
Developer Note
Macintosh LC 520 Computer

Developer Note
Developer Press
© Apple Computer, Inc. 2000

Apple Computer, Inc.
© 2000, Apple Computer, Inc.
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Contents
Figures and Tables
Preface
vii
About This Note
ix
Contents of This Note
ix
Supplemental Reference Documents
Conventions and Abbreviations
xi
Typographical Conventions
xi
Standard Abbreviations
xi
Chapter 1
Introduction
x
1
Summary of Features
2
Comparison With the Macintosh Color Classic
Comparison With the Macintosh LC III
3
Integrated Design
3
Front View
3
Back View
4
Access to the Logic Board
4
Built-in Color Display
4
Screen Control Pushbuttons
5
Video RAM
6
Power On and Off
6
Power Saver
7
RAM Expansion
8
RAM Configurations
8
RAM SIMM
8
PDS Expansion Slot
10
SCSI Bus
10
SCSI Connectors
10
SCSI Bus Termination
10
Comparison of SCSI Arrangements
12
Floppy Disk Drive
12
Serial I/O Ports
13
ADB Ports
15
Sound
15
Microphone
16
Sound Input Jack
16
Sound Control Pushbuttons
16
Keyboard
16
2
iii
Chapter 2
Architecture
19
Block Diagram
20
MC68030 Microprocessor
20
Ardbeg Custom IC
20
Ariel Custom IC
20
Combo Custom IC
22
Cuda ADB Controller
22
Sound Circuits
22
Sound Modes
22
Sample Rates
23
Address Map
23
RAM Addresses
23
Video RAM
25
Video Display Timing
25
Chapter 3
Expansion
29
Expansion Slot
30
Pin Assignments
30
Descriptions of the Signals
32
The PDS Expansion Card
34
Expansion Card Connectors
35
Address Space for the Expansion Card
Power for the Expansion Card
36
Chapter 4
Software
37
ROM Software
38
Unchanged Functions
38
MMU Initialization
38
Machine Identification
38
RAM Sizing and Addressing
38
One-Second Interrupt
39
Pushbutton Interrupts
39
Power Saver Software
39
Video Software
39
System Software
40
System Enabler
40
Booting From a CD-ROM
40
New Control Panels
40
Sound Control Panel
41
Screen Control Panel
42
iv
35
The Screen Driver
42
Screen Driver Calls
42
Open
43
Control
43
Status
44
Chapter 5
Internal Storage Devices
45
Storage Device Slide-In Bays
46
Front Drive Bezel
47
Connector Adapters
48
Internal CD-ROM Drive
48
Dimensions of the CD-ROM Drive
48
Mounting Method for the CD-ROM Drive
Power for the CD-ROM Drive
50
Internal CD-ROM Integration
51
Appendix
AppleCD 300i Specifications
General Information
Specifications
53
Index
Foldouts
50
53
53
55
59
v
Figures and Tables
Chapter 1
Chapter 2
Chapter 3
Chapter 4
Introduction
1
Figure 1-1
Figure 1-2
Figure 1-3
Figure 1-4
Figure 1-5
Figure 1-6
Front view of the Macintosh LC 520 computer
Back view of the Macintosh LC 520 computer
Screen control panel
7
RAM configurations
8
RAM expansion SIMM
9
Serial port sockets
14
Table 1-1
Table 1-2
Table 1-3
Table 1-4
Table 1-5
Table 1-6
VRAM size and number of colors
6
Pin assignments for the internal and external
SCSI connectors
11
Pin assignments for the internal floppy disk connector
Serial port signals
14
ADB connector pin assignments
15
Reset and NMI key combinations
17
Architecture
19
Figure 2-1
Figure 2-2
Figure 2-3
Figure 2-4
Block diagram
21
24-bit and 32-bit address maps
Standard video timing
26
Video timing for the Apple IIe card
Table 2-1
Table 2-2
Video parameters for the standard display
Video parameters for the Apple IIe display
Expansion
4
5
13
24
28
25
27
29
Figure 3-1
Generating the card select signal
Table 3-1
Table 3-2
Table 3-3
Table 3-4
Table 3-5
Signals on the 96-pin section of the expansion connector
31
Signals on the 18-pin section of the expansion connector
32
Processor-direct expansion connector signal descriptions
32
Expansion slot signals not connected to the MC68030
33
Power available for the expansion card
36
Software
Figure 4-1
Figure 4-2
Figure 4-3
35
37
Sound control panel
Sound options
41
Screen control panel
41
42
vii
Chapter 5
Appendix
Internal Storage Devices
Figure 5-1
Figure 5-2
Figure 5-3
Figure 5-4
Figure 5-5
Figure 5-6
Figure 5-7
Installation of the internal CD-ROM drive
46
Front drive bezel
47
Connector locations on the CD-ROM drive
48
Connector locations on the hard disk drive
49
Dimensions of the CD-ROM drive
49
The AppleCD 300i mounted on the sled
50
Pins on the CD-ROM audio connector
51
Table 5-1
Power available for the AppleCD 300i CD-ROM drive
AppleCD 300i Specifications
Table A-1
viii
45
53
AppleCD 300i specifications
53
50
P R E F A C E
About This Note
This developer note provides information about the Macintosh LC 520
computer, an integrated model with a built-in 14-inch color display. The
Macintosh LC 520 has about the same performance as the Macintosh LC III.
Note
While every attempt has been made to verify the accuracy of the
information presented here, it is subject to change without notice.
The primary reason for releasing this type of product information
is to provide the development community with essential product
specifications, theory, and application information for the purpose
of stimulating work on compatible third-party products. ◆
Contents of This Note
0
The information is arranged in five chapters, an Appendix, and a set of
foldouts:
■
Chapter 1, “Introduction,” gives a summary of the features and describes
the external features of the Macintosh LC 520 computer.
■
Chapter 2, “Architecture,” includes a block diagram and address maps and
describes the integrated circuits that are specific to the Macintosh LC 520
computer.
■
Chapter 3, “Expansion,” describes the single expansion slot in the
Macintosh LC 520 computer and the expansion card that plugs into it.
■
Chapter 4, “Software,” summarizes the features of the ROM software and
tells how the system software operates on the Macintosh LC 520 computer.
■
Chapter 5, “Internal Storage Devices,” is a developer guide for storage
devices to be installed inside the Macintosh LC 520 computer.
■
The Appendix gives the specifications for the AppleCD 300i, the internal
CD-ROM drive for the Macintosh LC 520 computer.
■
The foldouts provide engineering specifications and mechanical drawings
for selected parts.
ix
P R E F A C E
Supplemental Reference Documents
0
To supplement the information in this developer note, developers should have
copies of the appropriate Apple reference books, including Inside Macintosh,
Volumes IV, V, and VI; Guide to the Macintosh Family Hardware, second edition;
and Designing Cards and Drivers for the Macintosh Family, third edition. These
books are available in technical bookstores and through APDA.
Because the Macintosh LC 520 computer has many of the features of the
Macintosh LC II and LC III computers, developers should also have copies of
the developer notes that describe the Macintosh LC, LC II, and LC III. Those
are, respectively:
■
Macintosh IIsi, LC, and Classic Developer Notes, APDA catalog number
M0991LL/A
■
Macintosh Developer Note Number 1, APDA catalog number R0451LL/A
■
Macintosh Developer Note Number 3, APDA catalog number R0461LL/A
The developer notes are available from APDA and are also on the developer
CDs—the most recent, Macintosh Developer Note Number 3, has been available
since March 1993.
Note
The numbered developer notes are collections that describe several
Macintosh models. In addition to the Macintosh LC II computer,
Macintosh Developer Note Number 1 also covers the Macintosh IIvx,
the Macintosh PowerBook 145, 160, and 180, and the Macintosh
Quadra 950. Similarly, Macintosh Developer Note Number 3 covers the
Macintosh Color Classic, the Macintosh PowerBook 165c, the Macintosh
Centris 610 and 650, and the Macintosh Quadra 800 in addition to the
Macintosh LC III. ◆
APDA is Apple’s worldwide source for over three hundred development
tools, technical resources, training products, and information for anyone
interested in developing applications on Apple platforms. Customers receive
the quarterly APDA Tools Catalog featuring all current versions of Apple
development tools and the most popular third-party development tools.
Ordering is easy; there are no membership fees, and application forms are not
required for most of our products. APDA offers convenient payment and
shipping options, including site licensing.
x
P R E F A C E
To order products or to request a complimentary copy of the APDA Tools
Catalog, contact
APDA
Apple Computer, Inc.
P.O. Box 319
Buffalo, NY 14207-0319
Telephone
800-282-2732 (United States)
800-637-0029 (Canada)
716-871-6555 (International)
Fax
716-871-6511
AppleLink
APDA
America Online
APDA
CompuServe
76666,2405
Internet
APDA@applelink.apple.com
Conventions and Abbreviations
0
This developer note uses typographical conventions and abbreviations that
are standard in Apple publications.
Typographical Conventions
0
This note uses the following typographical conventions.
New terms appear in boldface where they are first defined.
Computer-language text—any text that is literally the same as it appears in
computer input or output—appears in Courier font.
Standard Abbreviations
0
When unusual abbreviations appear in this book, the corresponding terms
are also spelled out. Standard units of measure and other widely used
abbreviations are not spelled out.
Here are the standard units of measure used this developer note:
A
amperes
K
1024
dB
decibels
KB
kilobytes
GB
gigabytes
kg
kilograms
Hz
hertz
kHz
kilohertz
in.
inches
kΩ
kilohms
k
1000
lb.
pounds
xi
P R E F A C E
mA
milliamperes
µs
microseconds
µA
microamperes
ns
nanoseconds
MB
megabytes
sec.
seconds
MHz
megahertz
V
volts
mm
millimeters
W
watts
ms
milliseconds
Ω
ohms
Here are other abbreviations used in this developer note:
xii
$n
hexadecimal value n
AC
alternating current
ADB
Apple Desktop Bus
CD-ROM
compact-disk read-only memory
CLUT
color lookup table
EMI
electromagnetic interference
FPU
floating-point unit
IC
integrated circuit
I/O
input/output
LS
low-power Schottky (used as a standard for IC
device loads)
MMU
memory management unit
MOS
metal-oxide semiconductor
NMI
nonmaskable interrupt
PRAM
parameter RAM
PWM
pulse-width modulation
RAM
random-access memory
RMS
root-mean-square
ROM
read-only memory
SANE
Standard Apple Numerics Environment
SCC
serial communications controller
SCSI
Small Computer System Interface
SIMM
single inline memory module
SWIM
Super Woz Integrated Machine, a custom IC
that controls the floppy disk interface
TTL
transistor-transistor logic (used as a standard
for IC device loads)
VRAM
video RAM
C H A P T E R
Figure 1-0
Listing 1-0
Table 1-0
1
Introduction
1
C H A P T E R
1
Introduction
The Macintosh LC 520 computer is an integrated Macintosh computer with a built-in
color display. It is a larger version of the Macintosh Color Classic® with many of the
performance features of the Macintosh LC III.
This chapter outlines the main features of the Macintosh LC 520 computer and describes
its appearance and external features.
Summary of Features
1
Here is a summary of the hardware features of the Macintosh LC 520 computer
(individual features are described in the sections that follow):
■
integrated design with built-in 14-inch Trinitron color display
■
Motorola MC68030 microprocessor running at 25 MHz
■
built-in video hardware using separate video RAM
■
installed RAM capacity of 4 MB, expandable to 36 MB
■
1 MB ROM in sockets; optional expansion to 2 MB
■
internal hard disk with 40 MB, 80 MB, or 160 MB capacity, using the internal SCSI
connector; external SCSI port for additional SCSI devices
■
provision for an internal CD-ROM drive or other 5.25-inch storage device
■
internal Apple SuperDrive high-density floppy disk drive with 1.4 MB capacity
■
standard Macintosh I/O ports: two ADB ports, two serial ports, sound input and
output jacks, and a SCSI port
■
built-in microphone
■
front-panel headphone jack and internal stereo speakers
■
114-pin processor-direct slot (PDS) for hardware expansion (like the PDS on the
Macintosh LC III, and compatible with the 96-pin PDS on the Macintosh Color Classic
and the Macintosh LC II)
■
power on and off from the keyboard
■
pushbuttons on the front panel to control sound volume and display intensity
■
power saver mode to allow software to turn off the display monitor when the machine
is unused for a set period of time
Comparison With the Macintosh Color Classic
1
Here is a summary of features of the Macintosh LC 520 that are different from those of
the Macintosh Color Classic:
2
■
larger 14-inch Trinitron color display
■
microprocessor running at 25 MHz instead of 16 MHz; data bus 32 bits wide instead of
16 bits.
Summary of Features
C H A P T E R
1
Introduction
■
integrated case larger than that of the Macintosh Color Classic
■
RAM expandable to 36 MB instead of 10 MB
■
two internal speakers for stereo sound output
■
two sound output jacks, one in front, one in back
■
provision for an internal CD-ROM drive
■
extended processor-direct slot (PDS) for hardware expansion
Comparison With the Macintosh LC III
1
The Macintosh LC 520 computer combines the integrated design of the Macintosh Color
Classic with many of the functions and capabilities of the Macintosh LC III. Here is a
summary of features of the Macintosh LC 520 that are different from those of the
Macintosh LC III:
■
integrated design with a built-in 14-inch Trinitron color display
■
front-panel pushbuttons to control sound level and screen intensity
■
built-in microphone
■
stereo sound output, with built-in stereo speakers
■
two sound output jacks, one in front, one in back
■
provision for an internal CD-ROM drive
■
expansion socket for the system ROM
■
no external video connector
■
a different ADB controller IC (the Cuda)
Integrated Design
1
The Macintosh LC 520 computer has an integrated design similar to that of the Macintosh
Color Classic.
Front View
1
Figure 1-1 on page 4 shows the front of the Macintosh LC 520 computer, including the
display screen, the floppy disk slot, the CD-ROM slot, the front-panel headphone jack,
and the pushbuttons that control the screen intensity and sound level.
Integrated Design
3
C H A P T E R
1
Introduction
Figure 1-1
Front view of the Macintosh LC 520 computer
Built-in microphone
Color display
CD-ROM drive (optional)
Floppy disk drive
Stereo speakers
Headphone jack
Screen control buttons
Power-on light
Sound control buttons
Back View
1
Figure 1-2 shows the back of the Macintosh LC 520 computer. The master power switch is
located just beneath the fan grille. The external connectors are located in a row across the
lower part of the back.
Access to the Logic Board
1
Just above the row of I/O connectors on the back of the computer are two projecting tabs.
By pushing down on the tabs, the user can remove the connector cover and gain access to
the main logic board. The logic board has a custom connector that plugs into a socket at
the front so that the user can remove the board from the case by pulling it out the back.
Once the board has been removed, the user can add expansion RAM or plug in an
expansion card, as described in later sections of this note.
Built-in Color Display
The Macintosh LC 520 computer has a built-in color display with a 14-inch Trinitron
monitor. Like the video interface in the Macintosh Color Classic, the video interface
in the Macintosh LC 520 computer uses separate VRAM for the screen buffer. The
Macintosh LC 520 does not have an external video connector.
4
Built-in Color Display
1
C H A P T E R
1
Introduction
Figure 1-2
Back view of the Macintosh LC 520 computer
Power switch
Power connector
ADB ports
Printer port
Modem port
SCSI port
Sound input jack
Sound output jack
Expansion card access
The display screen in the Macintosh LC 520 computer displays the same amount of
information as the Macintosh 14-inch color display: 640 by 480 pixels.
Note
The Macintosh LC 520 computer also provides a 16-color,
560-by-384-pixel display mode when an Apple IIe Card is
installed in the expansion slot. ◆
Screen Control Pushbuttons
1
The Macintosh LC 520 computer has two pairs of pushbuttons on the front panel. The
pair on the left controls the intensity of the screen: pressing the top button causes the
intensity to increase, and pressing the bottom button causes the intensity to decrease. If
the user holds down a button, the intensity continues to increase (or decrease) until it
reaches a maximum (or minimum). (The pair of pushbuttons on the right controls the
sound level.)
Note
The user can also control the screen brightness and contrast by means of
the Screen control panel, described in the section “Screen Control Panel”
on page 42. ◆
Built-in Color Display
5
C H A P T E R
1
Introduction
Video RAM
1
The Macintosh LC 520 computer comes with 512 KB of VRAM and a socket for a SIMM
with an additional 256 KB of VRAM. The VRAM expansion SIMM is the same 68-pin
SIMM used with the Macintosh LC III and Macintosh Quadra computers. It requires
VRAM devices with access times of 80 ns or less.
The basic 512 KB VRAM provides up to 8 bits per pixel; the screen displays up to 256
colors, software-selectable from a range of 16 million. With the VRAM SIMM installed,
the Macintosh LC 520 has 768 KB of VRAM, allowing it to display up to 16 bits per pixel,
which provides 32,768 colors. If the VRAM SIMM has been installed, the user can set
the display to 16 bits per pixel by opening the Monitors control panel and choosing
Thousands.
Table 1-1 lists the bits per pixel and numbers of colors available for the different sizes
of VRAM.
Table 1-1
VRAM size and number of colors
VRAM size
Bits per pixel
Number of colors
512 KB
1, 2, 4, or 8
2, 4, 16, or 256
768 KB
1, 2, 4, 8, or 16
2, 4, 16, 256, or 32,768
(only 15 bits are used)
Power On and Off
1
The master power switch on the back of the computer must be in the On position for the
computer to operate. As long as the master power switch is in the On position, the user
can turn the power off and on by pressing the power key on the keyboard.
Note
If you plan to leave the computer turned off for an extended period of
time, you should flip the master power switch to the Off position. ◆
If the user attempts to turn off the computer—using either the power key or the Shut
Down menu item—while files are still open, the system displays an alert box warning the
user that files are open and should be closed to avoid loss of data. If the user turns off the
master power switch while the computer is operating, the computer shuts off
immediately, without performing the safe shutdown.
6
Power On and Off
C H A P T E R
1
Introduction
Power Saver
1
The power saver is an optional feature that automatically turns off the display whenever
the Macintosh LC 520 computer is turned on but is not used for more than a set period of
time. The user selects the power saver and sets the length of time before the screen turns
off by adjusting the slider in the Screen control panel, shown in Figure 1-3. After the
power saver has turned the display off, the software turns the display back on again
whenever the user moves the mouse or presses a key on the keyboard.
Figure 1-3
Screen control panel
Note
It may take up to several seconds for the screen display to reappear.
To let the user know that it has responded to the user’s action, the
computer emits a series of beeps while this is happening. ◆
Power Saver
7
C H A P T E R
1
Introduction
RAM Expansion
1
The Macintosh LC 520 computer comes with 4 MB of RAM built in. By installing a SIMM,
the user can expand the RAM up to a maximum of 36 MB.
RAM Configurations
1
Figure 1-4 shows the RAM configurations for different amounts of RAM. For more
information, see the section “RAM Addresses” on page 23.
Figure 1-4
4 MB
RAM configurations
5 MB
6 MB
8 MB
12 MB
20 MB
36 MB
RAM SIMM
The Macintosh LC 520 computer accepts one 72-pin RAM SIMM, illustrated in
Figure 1-5. The access time of the RAM must be 80 ns or less. The RAM SIMM can
contain 1 MB, 2 MB, 4 MB, 8 MB, 16 MB, or 32 MB of additional RAM.
Note
The SIMM used in the Macintosh LC 520 computer is not the same as the
30-pin SIMMs used on some other Macintosh computers. ◆
8
RAM Expansion
1
C H A P T E R
1
Introduction
Figure 1-5
RAM expansion SIMM
-BR 1.57 ± 0.1
[.062 ± .004]
32.0 [1.26]
MAX
10.16 ± 0.20
[.400 ± .008]
6.35 ± 0.20
[.250 ± .008]
3.38
[.133]
-A-
(6.35)
[.250]
1
2.03 ± 0.20
[.080 ± .008]
101.19 ± 0.20
[3.98 ± .008]
SEE DETAIL A
35 X 1.27 [.050] =
44.45 ± 0.20
[1.75 ± .008]
6.35 ± 0.05
[.250 ± .002]
107.95 ± 0.20
[4.25 ± .008]
0.10 [.004] M A B
R 1.57 ± 0.12
[.062 ± .005]
35 X 1.27 [.050] =
44.45 ± 0.20
[1.75 ± .008]
2X Ø3.18 ± 0.1
[.125 ± .004]
2.03
[.080]
MIN
0.25
[.010]
MAX
0.90 +0.17
- 0.08
.035 +.003
- .003
2.54 [.100]
MIN
1.27 ± 0.10
[.050 ± .004]
1.27 +0.10
- 0.08
.050 +.004
- .003
9.4 [.37]
MAX
Device on this
side optional.
DETAIL A
ROTATED 90°CCW
Note: Dimensions are in millimeters with inches in brackets.
RAM Expansion
9
C H A P T E R
1
Introduction
PDS Expansion Slot
1
The Macintosh LC 520 computer has a single internal 114-pin expansion connector that
provides direct access to the MC68030 microprocessor from an optional expansion card.
The connector can accept a 96-pin expansion card similar to the PDS card for the
Macintosh Color Classic. Like the PDS connector on the Macintosh LC III, it can also
accept an expansion card that uses all 114 pins to make better use of the power of the
MC68030 microprocessor. Chapter 3, “Expansion,” describes the signals on the PDS
connector and gives guidelines for designing a PDS card for the Macintosh LC 520.
Note
The PDS connector in the Macintosh LC 520 computer accepts the
Apple IIe Card for the Macintosh LC. The internal display provides a
560-by-384-pixel, 16-color display for running Apple IIe software. ◆
SCSI Bus
1
In addition to the internal hard drive and one or more external SCSI devices, the SCSI bus
on the Macintosh LC 520 computer supports the optional internal CD-ROM drive.
SCSI Connectors
1
The internal SCSI connector is a 50-pin connector with the standard SCSI pin
assignments. The external SCSI connector is a 25-pin D-type connector with the
same pin assignments as those in other Apple SCSI devices. Table 1-2 shows the
pin assignments on the internal and external SCSI connectors.
The internal hard disk and optional CD-ROM drive connect to the SCSI bus by means of
connector adapters that allow the drives to slide into their respective mounting bays. For
more information about the internal drives and connector adapters, see Chapter 5,
“Internal Storage Devices.”
SCSI Bus Termination
1
Because the internal portion of the SCSI bus must be long enough to connect multiple
devices, the bus requires termination at both ends. As on other Macintosh models, the
external end of the bus is normally terminated at the last external device. On the
Macintosh LC 520 computer, the internal end of the bus—the end at the last internal hard
disk drive—is terminated in the drive itself.
10
PDS Expansion Slot
C H A P T E R
1
Introduction
Table 1-2
Pin assignments for the internal and external SCSI connectors
Internal
(50-pin)
External
(25-pin)
Signal name
2
8
/DB0
4
21
/DB1
6
22
/DB2
8
10
/DB3
10
23
/DB4
12
11
/DB5
14
12
/DB6
16
13
/DB7
18
20
/DBP
20, 22, 24, 28,
30, and 34
–
n.c.
26
25
TPWR
32
17
/ATN
36
6
/BSY
38
5
/ACK
40
4
/RST
42
2
/MSG
44
19
/SEL
46
15
/C/D
48
1
/REQ
50
3
/I/O
All odd pins
(25 total)
7, 9, 14, 16,
18, and 24
GND
The Macintosh LC 520 computer includes a new feature that automatically provides the
proper termination when no external device is connected, that is, when the SCSI bus ends
at the external connector. When no external device is connected, special circuitry connects
the bus to a terminator on the logic board near the external connector. When one or more
external SCSI devices are connected, the circuitry detects the external termination during
system reset and disconnects the termination on the logic board.
SCSI Bus
11
C H A P T E R
1
Introduction
Comparison of SCSI Arrangements
1
There are now three arrangements of SCSI cabling and termination used in
Macintosh computers.
The first arrangement is used on Macintosh computers that support only one internal
SCSI device (examples include the Macintosh LC II and the Macintosh Quadra 700).
Terminators built into the internal SCSI device terminate the internal end of the SCSI bus.
A separate terminator block at the last external device terminates the external end of the
SCSI bus.
The second arrangement is used on the Macintosh Quadra 900 and 950 computers. Those
machines have two SCSI driver ICs, one for the internal SCSI devices and one for the
external devices. (The software treats the two hardware buses as one virtual bus with a
single set of SCSI ID numbers.) The internal and external SCSI cables are both terminated
on the logic board. In addition, the internal cable is so long that it—like the external
cable—requires termination at both ends, so it has built-in SCSI terminators for the last
device. While this arrangement provides for higher transmission speeds because the two
segments of the bus are terminated separately, it is expensive because it has two driver
ICs and two sets of active terminators on the logic board.
The third arrangement is used in the Macintosh LC 520 computer as well as other
recently introduced models with more than one internal SCSI device (such as the
Macintosh IIvx and the Macintosh Centris 650). As described earlier, that arrangement
uses a single SCSI driver IC for both internal and external devices and provides
automatic termination on the logic board.
Floppy Disk Drive
1
The Macintosh LC 520 computer supports one internal high-density floppy disk drive
(Apple SuperDrive). The drive is connected to the logic board by a 20-pin connector.
Table 1-3 shows the pin assignments for the floppy disk connector.
The floppy disk drive uses a special connector adapter that allows it to be installed by
sliding it into a bay in the computer’s chassis. See Chapter 5, “Internal Storage Devices,”
for information about connector adapters.
12
Floppy Disk Drive
C H A P T E R
1
Introduction
Table 1-3
Pin assignments for the internal floppy disk connector
Pin
number
Signal name
Signal description
1
GND
Ground
2
PH0
Phase 0: state control line
3
GND
Ground
4
PH1
Phase 1: state control line
5
GND
Ground
6
PH2
Phase 2: state control line
7
GND
Ground
8
PH3
Phase 3: register write strobe
9
n.c.
Not connected
10
/WRREQ
Write data request
11
+5V
+5 volts
12
SEL
Head select
13
+12V
+12 volts
14
/ENBL
Drive enable
15
+12V
+12 volts
16
RD
Read data
17
+12V
+12 volts
18
WR
Write data
19
+12V
+12 volts
20
n.c.
Not connected
Serial I/O Ports
1
The Macintosh LC 520 computer has two serial ports, one for a printer and one for a
modem. The printer port uses the standard 8-pin mini-DIN socket. The modem port uses
a 9-pin mini-DIN socket. Both sockets accept 8-pin plugs, but only the modem port
accepts a 9-pin plug. Figure 1-6 on page 14 shows the mechanical arrangement of the pins
on the serial port sockets; Table 1-4 on page 14 shows the signal assignments.
Serial I/O Ports
13
C H A P T E R
1
Introduction
Figure 1-6
8
Serial port sockets
7
5
6
4
2
8
3
5
1
Printer
7
6
9
4
2
1
3
Modem
Table 1-4
Serial port signals
Pin
number
Signal description
1
Handshake output
2
Handshake input
3
Transmit data –
4
Ground
5
Receive data –
6
Transmit data +
7
General-purpose input
8
Receive data +
9
+5 volts (modem port only)
The extra pin on the modem connector provides +5V power from the ADB power supply.
A modem should draw no more than 100 mA from that pin. The total current available
for all devices connected to the +5V supply for the ADB and the modem port is 500 mA.
Both serial ports include the GPi (general-purpose input) signal on pin 7. The GPi signal
for each port connects to the corresponding data carrier detect input on the SCC (Serial
Communications Controller). On serial port A (the modem port), the GPi line can be
connected to the receive/transmit clock (RTxCA) signal on the SCC. That connection
supports devices that provide separate transmit and receive data clocks, such as
synchronous modems. For more information about the serial ports, see Guide to the
Macintosh Family Hardware, second edition.
14
Serial I/O Ports
C H A P T E R
1
Introduction
ADB Ports
1
The ADB ports are functionally the same as those on other Macintosh computers.
The Apple Desktop Bus is a single-master, multiple-slave serial communications bus that
uses an asynchronous protocol and connects keyboards, graphics tablets, mouse devices,
and other devices to the Macintosh LC 520 computer. The custom ADB microcontroller
drives the bus and reads status from the selected external device. A 4-pin mini-DIN
connector connects the ADB controller to the outside world. Table 1-5 lists the ADB
connector pin assignments. For more information about the ADB, see Guide to the
Macintosh Family Hardware, second edition.
Table 1-5
ADB connector pin assignments
Pin
number
Name
Description
1
ADB
Bidirectional data bus used for input and output. It is an opencollector signal pulled up to +5 volts through a 470-ohm resistor
on the main logic board.
2
PSW
Power-on signal that generates reset and interrupt key
combinations.
3
+5V
+5 volts from the computer. A 1-ampere fuse at the output
satisfies safety requirements.
4
GND
Ground from the computer.
Note
The total current available for all devices connected to the +5V pins on
the ADB and the modem port is 500 mA. Each device should use no
more than 100 mA. ◆
Sound
1
Like other Macintosh computers, the Macintosh LC 520 computer can create sounds
digitally and play the sounds through its internal stereo speakers or send the
sound signals out through the sound out connectors. For recording sound, the
Macintosh LC 520 computer has a built-in microphone as well as an external sound input
jack.
The sound system includes a playthrough feature that allows an external audio source
to be mixed with computer-generated sound and played through the speakers or the
sound out connector. For more information, see the section “Sound Modes” beginning on
page 22.
ADB Ports
15
C H A P T E R
1
Introduction
Microphone
1
The Macintosh LC 520 computer has a built-in microphone at the front of the case. The
microphone is connected internally to the main logic board.
The user selects the built-in microphone as the sound source by using the Sound control
panel. For more information, see the section “Sound Control Panel” beginning on
page 41.
Sound Input Jack
1
There is a sound input jack on the back of the computer for connecting an external
microphone or other sound source. The sound input jack accepts a standard
1/8-inch phone plug, either monophonic or stereophonic (two signals plus ground).
The sound input jack accepts either the external microphone for the Macintosh LC 520
computer or a pair of line-level (amplified) signals. When the user selects the
corresponding input device in the Sound control panel, the computer sets the gain
appropriately. The internal circuitry mixes the pair of stereophonic signals into a
monophonic signal.
Note
The external microphone requires power from the main computer, which
it obtains by way of an extra-long, 4-conductor plug that makes contact
with a 5-volt pin inside the sound input jack. ◆
Sound Control Pushbuttons
1
The Macintosh LC 520 computer has two pairs of pushbuttons on the front panel. The
pair of buttons on the right controls the sound level: pressing the top button causes the
level to increase, and pressing the bottom button causes the level to decrease. (The left
pair of pushbuttons controls the intensity of the display.) If the computer is playing a
sound when you press one of the sound control pushbuttons, the sound level changes as
long as you continue to press the button. If no sound is playing when you press a sound
control pushbutton, the computer plays an alert sound to confirm the new level setting.
Keyboard
1
The Macintosh LC 520 computer comes with a separate keyboard like the one used with
the Macintosh Color Classic. The keyboard has a power key, identified by the symbol p.
There are no programmer’s switches on the Macintosh LC 520 case, so the reset and NMI
functions are generated by pressing the power key on the keyboard while holding down
other keys, as shown in Table 1-6. The Command key is identified by the symbols 
and x.
16
Keyboard
C H A P T E R
1
Introduction
Note
The user must hold down a key combination for at least 1 second to
allow the ADB microcontroller enough time to respond to the NMI
or hard-reset signal. ◆
Table 1-6
Reset and NMI key combinations
Key combination
Function
Power (p)
Power on and off
Command-Power (x-p)
NMI (always active)
Control-Command-Power
(Control-x-p)
Reset
Note
The NMI in the Macintosh LC 520 computer can always be activated
from the keyboard. This is a change from the Macintosh LC computer,
where the keyboard NMI function can be deactivated by the software.
Keyboard
◆
17
C H A P T E R
Figure 2-0
Listing 2-0
Table 2-0
2
Architecture
2
C H A P T E R
2
Architecture
This chapter describes the architecture of the Macintosh LC 520 computer. It describes
the main components on the logic board and explains the features that are different from
those of earlier Macintosh computers.
Block Diagram
2
The architecture of the Macintosh LC 520 computer is based on the design of the
Macintosh LC III. The Macintosh LC 520 uses several new custom ICs, as shown
in the block diagram in Figure 2-1.
MC68030 Microprocessor
2
The Macintosh LC 520 computer uses a Motorola MC68030 microprocessor running at a
clock speed of 25 MHz.
The Macintosh LC 520 computer does not have a built-in floating-point unit (FPU). The
main circuit board has a socket for adding an FPU. Also, an expansion board can provide
an FPU, because the /FPU select signal is available on the expansion connector. For more
information, see Chapter 3, “Expansion.”
Ardbeg Custom IC
2
A custom IC called Ardbeg combines several functions performed by individual ICs in
older machines:
■
timing and clock generation
■
memory mapping
■
VIA1 and VIA2 registers
■
video addressing and timing
■
SWIM II floppy disk interface
■
sound timing and control
■
interface to front-panel pushbuttons
The VIA functions are similar to those in the Macintosh LC III. The first VIA is a
full-function VIA, and the second is a set of registers like those in the V8 custom IC.
Ariel Custom IC
2
Another custom IC, called Ariel, contains the video CLUT (color look-up table) and DAC.
The Ariel IC is pin and software compatible with the AC843 but does not support 24 bits
per pixel. For information about the number of bits per pixel provided on different video
monitors, see the section “Video RAM” on page 25.
20
Block Diagram
C H A P T E R
2
Architecture
Figure 2-1
Block diagram
Processor direct slot
A21–2
ROM
ROM SIMM
Bidirectional
bus
transceivers
CPU
D31–0
MC68030
A31–0
D31–0
A31–0
D31–0
D31–0
FPU
socket
MC68882
RA10–0
RAM
RAM SIMM
Bidirectional
bus
transceivers
14-inch
video
monitor
VRAM
VRAM SIMM
D31–0
D15–0
Ariel
A31,
A23–0
Ardbeg
Custom
system
controller
IC
Connector for internal
floppy disk drive
Monitor
circuitry
CLUT/DAC
(includes
SWIM II
floppy disk
controller)
Speaker
amplifier
Internal
speakers
External
sound
output
DFAC II
Output
filter
Internal mic
Pushbuttons
Input
amplifier,
AGC, &
filter
ADC
External
mic input
Cuda
DFAC control
ADB ports
(68HC05)
ADB
microcontroller
ADB
transceiver
Connector for internal
SCSI hard disk drive
A6–4
D31–24
A2 A1
Block Diagram
85C80
Combo
(includes
SCC and
SCSI
controller)
Ch. A
Ch. B
Port A (modem)
Drivers &
receivers
External
SCSI port
Serial ports
Port B (printer)
21
C H A P T E R
2
Architecture
Combo Custom IC
2
In the Macintosh LC 520 computer, the functions of two interface ICs, the SCC (85C30)
and the SCSI (53C80), are combined into one device, the Combo IC (85C80). The SCSI
port on the Macintosh LC 520 is the same as that on the Macintosh LC III.
The SCC (serial) ports are also like their counterparts except that they include the GPi
signal (on pin 7). The GPi signal can be used for input handshaking or for a receive clock
input to support a synchronous modem. The pin assignments for the serial ports are
listed in Table 1-4 on page 14.
Cuda ADB Controller
2
The Cuda IC is a version of the 68HC05 microcontroller. It provides the ADB interface
and control signals to the DFAC II IC along with parameter RAM, the real-time clock,
and soft-power control. For a description of soft power, see the section “Power On and
Off” beginning on page 6.
Sound Circuits
2
The analog sound processing devices in the Macintosh LC 520 computer are built into a
custom IC called the DFAC II. In addition, the Ardbeg custom IC performs sound routing
and control along with its other digital functions.
For sound input, the DFAC II processes the signal from the internal microphone or the
sound input jack through a sound input amplifier (with automatic gain control), an input
filter, an A/D converter, and the necessary switching circuits.
For sound output, circuits in the Ardbeg custom IC receive data from the sound buffer
and generate a pulse-width-modulated (PWM) signal that is sent to the DFAC II. After
low-pass filtering in the DFAC II, the signal is sent to the sound output jacks and to
separate amplifiers that drive the built-in speakers. Inserting a plug into either sound
output jack disconnects the internal speakers.
Sound Modes
The DFAC II is normally used in one of four modes of operation:
22
■
Sound playback: computer-generated sound is sent to the speaker and the sound
output jack.
■
Sound playback with playthrough: computer sound and sound input are mixed and
sent to the output.
■
Sound record: sound input is recorded; this is the preferred method for recording,
especially when using the built-in microphone.
■
Sound record with playthrough: input sound is recorded and also fed through to
the output.
Block Diagram
2
C H A P T E R
2
Architecture
One way of using sound record with playthrough is in the recording of sounds from a
CD or CD-ROM.
IMPORTANT
As in the Macintosh LC, the sound mode is selected by means of a call
to the Sound Manager. To prevent feedback that might be audible, an
application should not let the user select select playthrough mode when
either microphone has been selected as the sound input source. For more
information, see the section “Sound Control Panel” beginning on
page 41. ▲
Sample Rates
2
The Macintosh LC 520 computer records and plays back sound at either of two sample
rates: 11k samples per second and 22k samples per second. For sound input, the system
switches the input filter between two cutoff frequencies that correspond to the two
sampling rates: 3.5 kHz cutoff for the 11k sample rate and 7 kHz cutoff for the 22k sample
rate.
Similarly on playback, the system switches between a filter with a 3.5 kHz cutoff
frequency for sounds at 11k samples per second and a 7 kHz filter for sounds at 22k
samples per second.
Address Map
2
The Macintosh LC 520 computer supports both 24-bit and 32-bit addressing. Figure 2-2
on page 24 shows the relationship between the 24-bit addresses and the 32-bit addresses.
The address map is similar to that of the Macintosh LC III.
Note
Developers should not use actual hardware addresses in applications but
should always communicate with hardware devices by means of system
software. ◆
RAM Addresses
2
The first 1 GB of the address space is reserved for RAM. The actual amount of RAM
installed can be from 4 MB to 36 MB. At startup time, a routine in the ROM determines
the amount of RAM available and stores the size in a low-memory global variable.
Address Map
23
C H A P T E R
2
Architecture
Figure 2-2
24-bit and 32-bit address maps
Expansion slot
$FFFF FFFF
$FE00 0000
$F000 0000
NuBus
super
slot
space
$7000 0000
$60FF FFFF
Video RAM
$50FF FFFF
$FF FFFF
$F0 0000
$E0 0000
$6000 0000
I/O
I/O
Expansion slot
$4020 0000
ROM
$C0 0000
$5000 0000
$4000 0000
Video RAM
$B0 0000
$90 0000
ROM
$80 0000
RAM
(up to 8 MB)
$023F FFFF
RAM
$00 0000
24-bit address space
24
Address Map
32-bit address space
$0000 0000
C H A P T E R
2
Architecture
Video RAM
2
The Macintosh LC 520 computer uses separate video RAM (VRAM) to store the screen
buffer. The video RAM occupies a dedicated address space, as shown in Figure 2-2.
The computer comes with 512 KB of VRAM soldered to the main logic board. A
68-pin SIMM socket accepts an additional 256 KB for a total of 768 KB of VRAM.
The VRAM SIMM is the same size and has the same pin assignments as the VRAM
expansion SIMM for the Macintosh Display Card 8•24. The system interface to the
VRAM is a 16-bit data bus using bits 31–16.
Note
The 256 KB VRAM SIMM used in the Macintosh LC 520 computer is the
same as that used in the Macintosh Color Classic; it is not the same as the
512 KB VRAM SIMM used in the Macintosh LC and Macintosh LC II
computers. ◆
A color lookup table (CLUT) provides color values for 4-bit and 8-bit video modes. With
the Monitors control panel set to black-and-white, the CLUT is still used, but all three
color components (R, G, and B) are the same.
Video Display Timing
2
The standard video display on the Macintosh LC 520 computer has the same number of
pixels as the display used with the AppleColor High-Resolution RGB Monitor: 640 by 480
pixels. Table 2-1 lists the video parameters; Figure 2-3 on page 26 shows the timing and
the synchronizing signals.
Table 2-1
Video parameters for the standard display
Parameter
Value
Dot clock
30.24 MHz
Dot time
33.07 ns
Line rate
35.00 kHz
Line time
28.57 µs
Frame rate
66.67 Hz
Frame time
15.00 ms
Video Display Timing
25
C H A P T E R
2
Architecture
Figure 2-3
Standard video timing
Horizontal timing
White
Video
Video
Black
224 dots
640 dots
HBLANK
864 dots
/HSYNC
Back porch = 96 dots
Horizontal sync pulse = 64 dots
Front porch = 64 dots
;;;;;;
;;;;;;
;;;;;;
Vertical timing
Video
;;;;;;;;;;;;
;;;;;;;;;;;;
;;;;;;;;;;;;
Lines of video
45 lines
480 lines
VBLANK
525 lines
/VSYNC
Back porch = 39 lines
Vertical sync = 3 lines
Front porch = 3 lines
26
Video Display Timing
;;;
;;;
;;;
White
Black
C H A P T E R
2
Architecture
When the Apple IIe Card for the Macintosh is installed in the expansion slot, the
Macintosh LC 520 computer generates a 560-by-384-pixel video display. Table 2-2 lists the
video parameters for the Apple IIe display and Figure 2-4 on page 28 shows the timing
and synchronizing signals.
Table 2-2
Video parameters for the Apple IIe display
Parameter
Value
Dot clock
17.234 MHz
Dot time
58.02 ns
Line rate
24.48 kHz
Line time
40.85 µs
Frame rate
60.15 Hz
Frame time
16.63 ms
Video Display Timing
27
C H A P T E R
2
Architecture
Figure 2-4
Video timing for the Apple IIe card
Horizontal timing
White
Video
Video
Black
144 dots
560 dots
HBLANK
704 dots
/HSYNC
Back porch = 80 dots
Horizontal sync pulse = 32 dots
Front porch = 32 dots
Vertical timing
;;;;;
;;;;;
Video
;;;;;;;;;;;;
;;;;;;;;;;;;
Lines of Video
23 lines
384 lines
VBLANK
407 lines
/VSYNC
Back porch = 19 lines
Vertical sync = 3 lines
Front porch = 1 line
28
Video Display Timing
;;;
;;;
White
Black
C H A P T E R
Figure 3-0
Listing 3-0
Table 3-0
3
Expansion
3
C H A P T E R
3
Expansion
The expansion feature of the Macintosh LC 520 computer is a processor-direct slot that
connects directly to the MC68030 microprocessor. This chapter describes the expansion
slot and gives the specifications for an expansion card.
Expansion Slot
3
The expansion slot in the Macintosh LC 520 computer is an extended processor-direct slot
that accepts either of two types of PDS cards: the 96-pin PDS card used in the
Macintosh LC II computer or the 114-pin PDS card used in the Macintosh LC III. The
114-pin connector provides additional signals to support features of the MC68030
microprocessor that are not available with the 96-pin card.
Note
An expansion card designed for the Macintosh LC II computer will work
in the Macintosh LC 520 computer if the card’s designer has followed the
guidelines in Designing Cards and Drivers for the Macintosh Family, third
edition. ◆
The PDS expansion connector in the Macintosh LC 520 computer is mechanically the
same as the expansion connector in the Macintosh LC III. It is essentially a 120-pin
Euro-DIN connector with six pins removed to make a notch. The notch divides the
connector into two sections: a 96-pin section that accepts the 96-pin connector used
on expansion cards for the Macintosh LC II, and a separate 18-pin section for the
additional signals.
Pin Assignments
3
Pins numbered 1–32 in rows A, B, and C correspond to the 96-pin section of the
connector. Table 3-1 gives the pin assignments for the 96-pin section.
Except for one signal, 16MASTER (on pin B31 and described in Table 3-4), the pin
assignments on the 96-pin section of the extended PDS are the same as those on the PDS
in the Macintosh LC II. On the Macintosh LC II, pin B31 is the Apple II clock input.
Pins 33 and 34 in all three rows are missing—those pins correspond to the notch in the
connector. Pins 35–40 in rows A, B, and C make up the 18-pin section of the extended
connector. Table 3-2 on page 32 gives the pin assignments for the 18-pin section.
Note
Signal names starting with a slash (/) are active when their signal lines
are driven to a logical zero (0). ◆
IMPORTANT
Under no circumstances should you use the Analog GND pin (Pin 1,
Row B) for a digital ground on your expansion card. Doing so will cause
digital noise to be coupled into the audio system, resulting in degraded
sound quality. ▲
30
Expansion Slot
C H A P T E R
3
Expansion
Table 3-1
Signals on the 96-pin section of the expansion connector
Pin
number
Row A
Row B
Row C
1
SNDOUT
Analog GND
/FPU.SEL
2
/SLOTIRQ
/R/W
/DS
3
/PDS.AS
+5V
/BERR
4
/PDS.DSACK1
+5V
/PDS.DSACK0
5
/HALT
SIZ1
SIZ0
6
FC2
GND
FC1
7
FC0
CLK16M
/RESET
8
RMC
GND
/SLOT.BG
9
D31
D30
D29
10
D28
D27
D26
11
D25
D24
D23
12
D22
D21
D20
13
D19
D18
D17
14
D16
D15
D14
15
D13
D12
D11
16
D10
D9
D8
17
/BGACK
/BR
A0
18
A1
A31
A27
19
A26
A25
A24
20
A23
A22
A21
21
A20
IPL2
IPL1
22
IPL0
D3
D4
23
D2
D5
D6
24
D1
D0
D7
25
A4
A2
A3
26
A6
A12
A5
27
A11
A13
A7
28
A9
A8
A10
29
A16
A15
A14
30
A18
A17
A19
31
n.c.
16MASTER
FC3
32
+12V
GND
–5V
Expansion Slot
31
C H A P T E R
3
Expansion
Table 3-2
Signals on the 18-pin section of the expansion connector
Pin
number
Row A
Row B
Row C
35
A28
/CPU.BG
CPU.CLK
36
A29
CPU.TYPE
A30
37
/CIOUT
/CPU.AS
/STERM
38
/CBACK
/CPU.DISABLE
/CBREQ
39
/SLOTIRQ.D
/DSACK0
/SLOTIRQ.C
40
CACHE
GND
/DSACK1
All the signals on the expansion connector are capable of driving at least one TTL load
(1.6 mA sink, 400 µA source). Most of the signals are connected to other MOS devices on
the main logic board; for those signals, the DC load on the bus signals is small. The
high-order 16 data lines (D16–D31) have one LS load connected to them.
Descriptions of the Signals
3
Most of the signals on the expansion connector are connected directly to the signal of the
same name on the MC68030 microprocessor. Table 3-3 describes the functions of those
processor-direct signals. Table 3-4 gives the signal descriptions for the signals that are not
connected to the MC68030.
Table 3-3
Processor-direct expansion connector signal descriptions
Signal name
Signal description
A0–A31
Address lines.
/BERR
Bus error; bidirectional signal indicating that invalid bus operation is being
attempted.
/BGACK
Bus grant acknowledge; input signal indicating that external device has become
bus master.
/BR
Bus request; input signal indicating that external device is requesting to become
bus master.
/CBACK
CPU burst acknowledge; used with /STERM during a burst transfer to indicate
that individual elements of a burst transfer are ready.
/CBREQ
CPU burst request; used to initiate a quadruple longword burst transfer.
/CIOUT
Cache inhibit out signal from main processor, indicating that a second-level cache
is allowed to participate in the current bus transaction.
/CPU.AS
Processor’s address strobe; three-state output signal indicating that an active bus
transaction is occurring.
continued
32
Expansion Slot
C H A P T E R
3
Expansion
Table 3-3
Processor-direct expansion connector signal descriptions (continued)
Signal name
Signal description
/CPU.BG
Processor bus grant; signal from the external device can become bus master
following completion of current processor bus cycle.
D0–D31
Data lines.
/DS
Data strobe. During read operation, /DS indicates that external device should place
data on data bus; during write operation, /DS indicates that the main processor has
placed valid data on the data bus.
/DSACK0,
/DSACK1
Data transfer acknowledge signals; indicate completion of data transfer operation
from main processor; inform the processor of the size of the data port.
FC0–FC2
Function code used to identify address space of current bus cycle.
/HALT
Signal indicating that main processor should suspend all bus activity.
IPL0–IPL2
Interrupt priority-level lines.
/RESET
Bidirectional signal that initiates system reset.
RMC
Three-state output signal that identifies current bus cycle as part of indivisible
read-modify-write operation.
/R/W
Read/write; three-state output signal that defines direction of bus transfer with
respect to the main processor.
SIZ0–SIZ1
Three-state output signals that work in conjunction with processor’s dynamic bus
sizing capabilities to indicate number of bytes remaining to be transferred during
current bus cycle.
/STERM
Connected to the /STERM signal on the main processor; indicates termination of a
transfer using the MC68030 synchronous cycle.
Table 3-4
Expansion slot signals not connected to the MC68030
Signal name
Signal description
CACHE
Signal from the card, indicating that the current bus transaction can be satisfied by
the external cache on the card.
CLK16M
Independent clock running at 15.6672 MHz; provided for compatibility with
Macintosh LC and LC II PDS cards.
CPU.CLK
Main processor clock (25.0 MHz).
/CPU.DISABLE
Disables the MC68030 CPU (and MC68882 FPU, if installed) on the main logic
board. This signal is used by a PDS card that replaces the main processor.
CPU.TYPE
Defines bus protocol for the PDS; logical one (1) for MC68020 and MC68030, logical
zero (0) for MC68040.
continued
FC3
Additional function code bit, used to indicate that the software is running
in 32-bit address mode. (As in the Macintosh LC II, the software always runs in
32-bit mode.)
Expansion Slot
33
C H A P T E R
3
Expansion
Table 3-4
Expansion slot signals not connected to the MC68030 (continued)
Signal name
Signal description
/FPU.SEL
Select signal for an optional MC68881 or MC68882 FPU on the card.
/PDS.AS
Address strobe synchronized to 16 MHz regardless of the actual processor speed;
used to indicate the occurrence of an active bus transaction. /PDS.AS is asserted
only when a valid slot address is being generated by the bus master or by an access
to the FPU. Slot addresses are in the slot $E range ($xxExxxxx in 24-bit mode,
$FExxxxxx or $Exxxxxxx in 32-bit mode). When a PDS card is the active bus master,
the card may drive either /PDS.AS or /CPU.AS, but not both.
/PDS.DSACK0,
/PDS.DSACK1
Data transfer acknowledge signals from the PDS card.
16MASTER
Indicates the width of the data port when the card is alternate bus master. A logical
one (1) indicates a 16-bit port; logical zero (0) indicates a 32-bit port. The signal is
pulled high on the main logic board.
/SLOT.BG
Bus grant signal to the expansion card. A bus master card may take control of the
system bus after all pending bus traffic has been completed (when /PDS.AS,
/BGACK, and all /DSACK signals are inactive).
/SLOTIRQ
Interrupt request line from the card; reported to the system by way of the SLOT.E
request; when low, generates a level-2 interrupt if the slot interrupt enable bit is set.
/SLOTIRQ.C,
/SLOTIRQ.D
For future expansion; not used in the Macintosh LC 520 computer.
SNDOUT
Input to the speaker amplifier so that the card can drive the speaker independently
of the main processor. This signal accepts only sound output by the method used
on the original Apple II, using 1’s and 0’s.
▲
W AR N I N G
The SNDOUT pin must not be grounded; doing so will short-circuit the
+5V power to the sound ciruitry. If you don’t use the SNDOUT pin, leave
it unconnected. ▲
The PDS Expansion Card
3
The PDS expansion card for the Macintosh LC 520 computer is approximately 3 inches
wide by 5 inches long. It mounts parallel to the main logic board and reaches to an
opening in the back of the case (normally filled by a snap-out cover). The opening
provides access to a 15-pin D-type connector on the card for external I/O.
The PDS card for the Macintosh LC 520 computer is the same size and shape as the PDS
card for the Macintosh LC III computer. The section “Foldouts” at the end of this
developer note contains mechanical drawings showing the recommended design
guidelines for the PDS card. Foldout 1 shows the maximum dimensions of the expansion
card and the location of the PDS connector. Foldout 2 provides component height
34
The PDS Expansion Card
C H A P T E R
3
Expansion
restrictions for the expansion card. Foldout 3 shows how the card is installed on the main
logic board.
Expansion Card Connectors
3
The custom 114-pin PDS connector on the computer’s main logic board accepts either a
96-pin or 120-pin standard Euro-DIN connector. You can order connectors meeting Apple
specifications from Amp Incorporated, Harrisburg, PA 17105 or from Augat
Incorporated, Interconnect Products Division, P. O. Box 779, Attleboro, MA 02703. Refer
to Designing Cards and Drivers for the Macintosh Family, third edition, for more information
about those connectors.
Address Space for the Expansion Card
3
The expansion card’s address space depends on the memory addressing mode. In 24-bit
mode, the card appears in the address space $E0 0000–$EF FFFF; in 32-bit mode, the card
appears in the address space $8000 0000–$FFFF FFFF. To match the conventions used by
the Slot Manager, software should address the card as if it were in slot space $E: either
the 16 MB slot space $FE00 0000–$FEFF FFFF or the super slot space
$E000 0000–$EFFF FFFF.
The expansion card must generate its own select signal from the address and function
code signals on the connector. The card select signal must be disabled when FC0, FC1,
and FC2 are all active; that condition corresponds to a function code of 111 (CPU space).
Figure 3-1 shows a typical logic circuit for generating the card select signal.
Figure 3-1
Generating the card select signal
A31
FC0
FC1
FC2
32-bit mode
select
Disable selection
on interrupt
acknowledge
cycles
FC3
A23
A22
A21
A20
Card
select
24-bit mode
select
IMPORTANT
To ensure compatibility with future hardware and software, you should
minimize the chance of address conflicts by decoding all the address bits.
To ensure that the Slot Manager recognizes your card, the card’s
declaration ROM must reside at the upper address limit of the 16 MB
address space ($FE00 0000–$FEFF FFFF). ▲
The PDS Expansion Card
35
C H A P T E R
3
Expansion
Power for the Expansion Card
3
The PDS card uses power supplied through the 96-pin connector. The maximum current
available at each supply voltage is shown in Table 3-5. The card must not dissipate more
than 5 W total; for example, if the card uses the maximum current at –5 V and +12 V, it
must not use more than 500 mA from the +5 V supply.
Table 3-5
▲
Power available for the expansion card
Voltage
Current
+5
1.0 A
–5
20 mA
+12
200 mA
W AR N I N G
Cards dissipating more than 5 watts may overheat and damage
the Macintosh LC 520 computer’s circuitry or cause it to become
inoperable. ▲
36
The PDS Expansion Card
C H A P T E R
Figure 4-0
Listing 4-0
Table 4-0
Software
4
4
C H A P T E R
4
Software
The first part of this chapter describes the software in the Macintosh LC 520 computer’s
ROM. The second part describes the system software that supports the new features of
the Macintosh LC 520 computer.
ROM Software
4
The ROM in the Macintosh LC 520 computer is based on the ROM for the
Macintosh LC III with the necessary changes to support machine-specific hardware.
Unchanged Functions
4
Many ROM software components in the Macintosh LC 520 computer are functionally the
same as their counterparts in the Macintosh LC III. Those components are
■
the Slot Manager
■
network booting routines
■
Color QuickDraw
■
floating-point arithmetic routines
■
SANE routines
The AppleTalk routines are no longer in the ROM; they are now in the system software,
but they are similar to their counterparts in the ROM in the Macintosh LC III.
MMU Initialization
4
The code has been modified to support the memory addressing used by the
Macintosh LC 520 computer. There are new MMU tables to match the address mapping.
Machine Identification
4
The ROM includes new tables and code for identifying the machine.
Applications can find out which computer they are running on by using the Gestalt
Manager routines; see Inside Macintosh, Volume VI. The 'gestaltMachineType' value
for the Macintosh LC 520 computer is 56 (hexadecimal $38).
RAM Sizing and Addressing
The Macintosh LC 520 computer uses the same code as the Macintosh LC III for
determining the size of RAM, for setting up the MMU to make the RAM addresses
contiguous, and for address decoding.
To be able to run with virtual memory active, the Macintosh LC 520 computer uses the
32-bit Memory Manager and runs in 32-bit mode.
38
ROM Software
4
C H A P T E R
4
Software
One-Second Interrupt
4
As on the Macintosh Color Classic and Macintosh LC III computers, the one-second
interrupt on the Macintosh LC 520 computer is provided by the ADB microcontroller,
which sends the one-second interrupt to the main processor as a pseudodevice
transaction. In those cases where a one-second interrupt has been missed, the ADB
microcontroller sends the current value of the real-time clock so that the system software
can update the value stored in the Time global variable.
Pushbutton Interrupts
4
The ROM in the Macintosh LC 520 computer includes routines for initializing the
pushbutton interrupt bits in the interrupt enable and flag registers and for initializing
other new registers that support the pushbuttons.
Pushing any of the four pushbuttons on the front of the case causes the machine to set a
bit in a new register, the Pushbutton register, which in turn causes a level-2 interrupt. The
interrupt handler disables the pushbutton interrupt until the button that caused the
interrupt is released.
Power Saver Software
4
The software that controls the brightness of the display also includes code that
implements the power saver mode, which turns off the power to the display after a set
interval of time. Applications can turn the monitor on and off and read its status by
making the appropriate call to the Screen driver (.BCScreen). For more information, see
the section “The Screen Driver” beginning on page 42.
Note
The screen can remain dark for several seconds after the screen is
reactivated, so the system emits a series of beeps to reassure the user that
the computer is still operating. The Screen driver call that turns
the monitor back on also causes a call to the Notification Manager to play
the SysBeep sounds. When the screen is being reactivated, the keyboard
and mouse are disabled until the screen reappears. ◆
Video Software
4
Video support on the Macintosh LC 520 computer uses the same code as that used in the
Macintosh LC III computer. The only difference is that VRAM is always present in
the Macintosh LC 520.
ROM Software
39
C H A P T E R
4
Software
System Software
4
The Macintosh LC 520 computer requires System 7.1 or a later version of system software.
The disk labeled “Install Me First” includes a system enabler file that contains the
resources the system needs to start up and initialize the Macintosh LC 520 computer.
The system disk includes an Installer application to install the control panels for the new
features of the machine.
System Enabler
4
Starting with the international release of System 7.1, each reference release of the
Macintosh system software supports a new startup extension, the system enabler. The
system enabler is a software resource that is able to perform the correct startup process
for one or more Macintosh computers.
As soon as the system software on disk takes over the startup process, it searches for all
system enablers that can start up the particular machine. Each system enabler contains a
resource that specifies which computers it is able to start up and the time and date of its
creation. If the system software finds more than one enabler for the particular computer,
it passes control to the one with the most recent time and date.
In general, the system enabler included in each reference release of system software is
able to start up all previous computers. The system enabler that accompanies a later
computer will be able to start up that computer, possibly using resources from the
previous reference release.
Booting From a CD-ROM
4
The Macintosh LC 520 computer can start up (boot) from a built-in CD-ROM drive.
Starting up in this fashion is not recommended, because the system software was not
designed to operate from a locked storage device—one that the software can’t write to.
The system software that Apple Computer uses on the system CD-ROM includes only
one control panel file—for setting the startup disk—along with Installer software to
install the system onto a hard disk. Developers may wish to use a similar arrangement to
distribute bulky software.
New Control Panels
4
The system software for the Macintosh LC 520 computer includes new control panels for
the sound level and the screen brightness and contrast.
40
System Software
C H A P T E R
4
Software
Sound Control Panel
4
The Sound control panel on the Macintosh LC 520 computer is able to update its slider to
reflect changes in the sound level caused by the user pressing one of the sound
pushbuttons on the front of the case. The control panel also has a Mute checkbox to turn
off the sound. When the user adjusts the sound level, either with the control panel or
with the pushbuttons, the software also turns off the Mute checkbox. Figure 4-1 shows
the Sound control panel.
Figure 4-1
Sound control panel
The Sound control panel also allows the user to select the source of sound input, which
can be either the built-in microphone or a device plugged into the sound input jack.
When the user clicks the Options button, a dialog box appears, as shown in Figure 4-2.
The user can then select either the internal microphone, an external microphone, or the
line-level inputs.
Either the external microphone or line-level inputs can be plugged into the sound input
jack. When the user selects the corresponding input device in the Sound control panel,
the computer sets the gain appropriately.
Figure 4-2
Sound options
System Software
41
C H A P T E R
4
Software
Screen Control Panel
4
The Screen control panel has sliders for adjusting brightness and contrast. The user can
adjust either slider by dragging with the mouse and can adjust the contrast using the
arrow keys or the number keys. Figure 4-3 shows the Screen control panel.
Figure 4-3
Screen control panel
Note
The Screen control panel uses minimum and maximum values supplied
by the Screen driver so as not to set the screen so dark that the user
cannot see the control panel to make further adjustments. ◆
The Screen Driver
4
Applications can read and set the brightness and contrast of the screen by making
appropriate status and control calls to the Screen driver (.BCScreen). The system
startup code uses the Screen driver to set the initial screen values.
The current values of brightness and contrast are stored as byte values in parameter
RAM. If the startup software finds a value below the minimum startup value, it sets
it to a default midrange value.
IMPORTANT
The Screen Driver is machine specific; it does not support
all Macintosh models. ▲
Screen Driver Calls
4
Screen driver calls use the ParamBlockRec method as described in the Device Manager
chapter of Inside Macintosh. The parameter passing conventions are the standard ones: the
calling program passes a pointer to the parameter block in register A0.
42
System Software
C H A P T E R
4
Software
Because the Screen driver is opened at startup and is never closed, and because there is
nothing to read or write, the following calls are not supported:
■
CloseDriver
■
FSRead
■
FSWrite
■
KillIO
The following are calls supported by the Screen Driver.
Open
4
PBOpen (paramBlock: ParmBlkPtr; async: BOOLEAN) : OSErr_Open
Parameter block
→
←
→
←
→
ioCompletion
ioResult
ioNamePtr
ioRefNum
ioPermssn
Nil.
noErr (zero).
Pointer to the name .BCScreen.
Driver’s reference number.
Must be fsCurPerm.
When the system software opens the Screen driver at startup time, the Device Manager
creates a device control entry (DCE) and stores its handle in the proper unit table entry.
Subsequent Open calls merely return refNum and a result (noErr). Programs can use the
Open call to obtain the refNum value for use in control and status calls.
High-level call:
OpenDriver (name: Str255; VAR refNum: INTEGER) : OSErr
Control
4
PBControl (paramBlock: ParmBlkPtr; async: BOOLEAN) : OSErr_Control
Parameter block
→
←
ioCompletion
ioResult
→
→
→
ioRefNum
csCode
csParam
System Software
Nil.
controlErr (–17) if csCode is unimplemented;
otherwise noErr (0).
Driver’s reference number.
Identifies the call; described below.
Depends on the call; described with the csCode values
where it is used (csParam is an array of 11 shorts).
43
C H A P T E R
4
Software
csCode values:
Name
Value
Description
CtrlScrnBright
$4301
Set screen brightness PWM value to
csParam[0] (value = 0-255).
CtrlSaveBright
$4302
Store current brightness to PRAM.
CtrlScrnCont
$4307
Set screen contrast PWM value to
csParam[0] (value = 0-255).
CtrlSaveCont
$4308
Store current contrast to PRAM.
CtrlScreenOff
$4309
Turn off power to internal monitor.
CtrlScreenOn
$4310
Turn on power to internal monitor.
High-level call:
Control(refNum: INTEGER; csCode: INTEGER; csParamPtr: Ptr) : OSErr
Status
4
PBStatus (paramBlock: ParmBlkPtr; async: BOOLEAN) : OSErr_Status
Parameter block
→
←
ioCompletion
ioResult
→
→
→
ioRefNum
csCode
csParam
Nil.
controlErr (–17) if csCode value is unimplemented;
otherwise, noErr (0).
Driver’s reference number.
Identifies the call; described below.
Depends on the call; described with the csCode values
where it is used (csParam is an array of 11 shorts).
csCode values:
Name
Value
Description
StatScrnBright
$5301
Return current screen brightness in
csParam[0](value = 0-255).
StatBrtMinMax
$5303
Return minimum and maximum brightness values:
csParam[0] = maximum brightness,
csParam[1] = minimum brightness.
StatScrnCont
$5307
Return current screen contrast in
csParam[0] (value = 0-255).
StatConMinMax
$5308
Return minimum and maximum contrast values:
csParam[0] = maximum contrast,
csParam[1] = minimum contrast.
StatScrnOnOff
$5309
Return state of internal monitor in
csParam[0]:
$00FF = monitor power is on,
$0000 = monitor power is off.
High-level call:
Status(refNum: INTEGER; csCode: INTEGER; csParamPtr: Ptr) : OSErr
44
System Software
C H A P T E R
Figure 5-0
Listing 5-0
Table 5-0
5
Internal Storage Devices
5
C H A P T E R
5
Internal Storage Devices
This chapter describes the internal storage devices in the Macintosh LC 520 computer.
The computer accommodates one floppy disk drive, one half-high hard disk, and an
optional AppleCD 300i CD-ROM drive.
IMPORTANT
This chapter describes the internal storage devices in the
Macintosh LC 520 computer, but does not include design guides for
developers. Because the front drive bezel does not include a separate
component for the CD-ROM drive, and because the internal drives
are specially modified to permit slide-in mounting, Apple Computer,
Inc., does not recommend that developers provide internal storage
devices for the Macintosh LC 520 computer. ▲
Storage Device Slide-In Bays
5
The hard disk drive, floppy disk drive, and optional CD-ROM drive slide into their
respective mounting bays in the computer chassis. Connections to each drive are made
by one or more connector adapters that fit onto the connector pins on the drive. When
you slide a drive into its bay, the connector adapter fits into a matching socket at the back
of the bay. Figure 5-1 shows how the AppleCD 300i CD-ROM drive slides into its bay in
the front of the computer. The other internal storage devices are installed in much the
same way, except that the bay for the hard disk drive is in the back of the computer,
behind the removable back cover.
Figure 5-1
Installation of the internal CD-ROM drive
Audio adapter
SCSI and power adapter
CD 300i
CD mounting sled
CD and FD bezel
Floppy disk drive
46
Storage Device Slide-In Bays
C H A P T E R
5
Internal Storage Devices
Front Drive Bezel
5
The front drive bezel has openings for access to removable media. On computers with no
internal CD-ROM drive, the bezel has only the opening for floppy disks. Figure 5-2
shows the two views of the front drive bezel for the Macintosh LC 520 computer with the
AppleCD 300i internal CD-ROM drive.
Note
To remove the front drive bezel, insert a flat screwdriver into the slot on
the bottom of the bezel and twist while sliding the bezel downwards. ◆
Figure 5-2
Front drive bezel
Storage Device Slide-In Bays
47
C H A P T E R
5
Internal Storage Devices
Connector Adapters
5
As Figure 5-1 illustrates, the Macintosh LC 520 computer uses special adapters that allow
internal storage devices to slide into place and plug directly into the computer. The
connectors on the devices themselves must be located properly so that the connector
adapters will fit. Figure 5-3 shows the connector locations on the internal CD-ROM drive.
Figure 5-4 shows the connector locations on the internal hard disk drive.
The internal hard disk uses a single connector adapter that incorporates both the signal
pins and the power pins. The optional CD-ROM drive uses two connector adapters. The
first of those is similar to the hard disk adapter and incorporates both signal and power
pins. The second adapter is for the separate audio connector.
Figure 5-3
Connector locations on the CD-ROM drive
124.4
64.4
49.5
14.9
11.4
1
Audio connector
SCSI connector
Power connector
32.1
33.5
Note: Dimensions are in millimeters
Center
for12-M3
screw
Internal CD-ROM Drive
5
This section describes the dimensions, mounting method, and power budget for the
AppleCD 300i CD-ROM drive installed in the Macintosh LC 520 computer.
Dimensions of the CD-ROM Drive
Figure 5-5 shows the dimensions of the AppleCD 300i CD-ROM drive. The Appendix
gives the other specifications of the AppleCD 300i.
48
Internal CD-ROM Drive
5
C H A P T E R
5
Internal Storage Devices
Figure 5-4
Connector locations on the hard disk drive
4.69
3.42
4.19
C28.96
89.92
Center of
6-32 bottom
mounting hole
Note: Dimensions are in millimeters
Figure 5-5
Dimensions of the CD-ROM drive
41.4 –0°.5
21.84 ±0.3
146.05 –0.5°
139.7 ±0.5
9.91 ±0.3
203.2
–0°.3
79.25 ±0.3
47.5 ±0.3
A
5
148.05 ±0.3
Mounting holes
for 4-M3 screws
0.8 ±0.5
CL
(0.3)
42.5
±0.2
(42.5 ±0.5)
CL
Note: Dimensions are in millimeters
Internal CD-ROM Drive
A
49
C H A P T E R
5
Internal Storage Devices
Mounting Method for the CD-ROM Drive
5
Figure 5-6 shows the AppleCD 300i CD-ROM drive mounted on the sled that secures it in
the mounting bay. The sled is included in the AppleCD 300i mounting kit for the
Macintosh LC 520 computer.
Figure 5-6
The AppleCD 300i mounted on the sled
CD drive
CD carrier
Power for the CD-ROM Drive
Table 5-1 shows the power budget for the AppleCD 300i CD-ROM drive in the
Macintosh LC 520 computer.
Table 5-1
50
Power available for the AppleCD 300i CD-ROM drive
Voltage
Current
+5
500 mA max.
+12
800 mA max.,
1.5 A peak (300 ms, 50% duty cycle)
Internal CD-ROM Drive
5
C H A P T E R
5
Internal Storage Devices
Note
The AppleCD 300i CD-ROM drive connects to the internal SCSI bus. The
drive does not have a SCSI terminator, because the internal SCSI bus is
terminated in the built-in hard disk. ◆
Internal CD-ROM Integration
5
Apple’s internal CD-ROM drive uses SCSI ID number 3.
Audio from the CD-ROM is connected to the computer by a separate connector adapter.
Figure 5-7 shows the pin assignments. Each channel has its own ground return; the
computer’s audio circuits have differential inputs. The maximum signal level for the
audio is 0.7 V ± 0.1 V RMS at 47 KΩ.
Figure 5-7
Pins on the CD-ROM audio connector
1. Right audio +
2. Right audio –
Key flange
3. Left audio –
4. Left audio +
Internal CD-ROM Drive
51
A P P E N D I X
Figure A-0
Listing A-0
Table A-0
AppleCD 300i Specifications
A
This Appendix describes the performance and capabilities of the AppleCD 300i drive, the
internal CD-ROM drive included in some configurations of the Macintosh LC 520
computer.
General Information
A
The AppleCD 300i supports the world wide standards and specifications for CD-ROM
and CD-digital audio discs described in the Sony/Phillips Yellow Book and Red Book.
The drive can read CD-ROM, CD-ROM XA, CD-I, and PhotoCD discs as well as play
standard audio discs.
For improved performance, the AppleCD 300i features a new double-speed mechanism
that supports sustained data transfer rates of 300 KB per second—double the transfer rate
of previous drives. A 256 KB buffer on the drive controller further enhances performance.
Specifications
A
Table A-1 lists the specifications and performance characteristics of the
AppleCD 300i drive.
Table A-1
AppleCD 300i specifications
Physical
Depth (excluding bezel)
203.2 mm (8.00 in.)
Width
146.0 mm (5.75 in.)
Height
41.4 mm (1.63 in.)
Weight
1.25 kg (2.75 lb.)
General
Spin up time (maximum)
3 sec. (double speed), 2 sec. (normal speed)
Spin down time (maximum)
1.5 sec. (double speed), 1 sec. (normal speed)
Eject time (maximum)
7 sec. (double speed), 6.5 sec. (normal speed)
continued
General Information
53
A P P E N D I X
A
AppleCD 300i Specifications
Table A-1
AppleCD 300i specifications (continued)
CD-ROM
Modes supported
CD-ROM (Mode 1 and Mode 2), CD-ROM XA
(Mode 2, Form 1 and Form 2), and CD-I
(Mode 2, Form 1 and Form 2)
Block lengths supported
CD-ROM Mode 1
CD-ROM Mode 2
CD-ROM XA
2048, 1024, and 512 bytes
2340, 2336, 1024, and 512 bytes
2647, 2353, and 2336 bytes
Blocks per disc
336,150 (typical)
Data capacity
656 MB, Mode 1
748 MB, Mode 2
Address description
Minutes, seconds, frames
Transfer rate (sustained)
300 KB/sec., Mode 1 (double speed)
150 KB/sec., Mode 1 (normal speed)
342.2 KB/sec., Mode 2 (double speed)
171.1 KB/sec., Mode 2 (normal speed)
Blocks per second
150 (double speed), 75 (normal speed)
Access time (typical)
Full stroke (first to last block)
Random (block to block)
Track to adjacent track
520 ms (double speed), 550 ms (normal speed)
295 ms (double speed), 350 ms (normal speed)
2 ms
SCSI transfer rate (burst)
1.5 MB/sec., Mode 1 and Mode 2, asynchronous
4 MB/sec., Mode 1 and Mode 2, synchronous
SCSI buffer memory
256 KB
Uncorrected error rate (maximum)
ECC enabled (Mode 1)
ECC disabled (Mode 1 or Mode 2)
< 1 bit error per 10–12 blocks read (double speed)
< 1 bit error per 10–15 blocks read (normal speed)
< 1 bit error per 10–9 blocks read (double speed)
< 1 bit error per 10–12 blocks read (normal speed)
CD-audio
54
Block lengths supported
2448, 2368, and 2352 bytes
Playing time
74 minutes, 42 seconds
Line output
0.7 volts RMS at 47 KΩ
Headphone output (front panel)
0.65 volts RMS at 32 Ω
Distortion
< 0.04 percent at 1 KHz
Signal to noise ratio
> 80 dB
Frequency response
5 Hz to 20 KHz
Specifications
Index
Numerals
24-bit addressing 23
32-bit addressing 23, 38
68HC05 microcontroller 22
A
abbreviations xi to xii
access to the logic board 4
ADB (Apple Desktop Bus) ports 15
ADB controller 22
address maps 24
address modes 23
AppleCD 300i 48
features 53
Apple IIe card 10
video display for 27
Apple SuperDrive 12
Ardbeg custom IC 20, 22
automatic termination 11
color lookup table (CLUT) 25
Combo IC 22
connector adapters 48
connectors
ADB 15
floppy disk 12
for expansion card 35
SCSI 10
serial I/O 13
sound input jack 16, 41
sound output jack 22
Control call 43
control panels
Screen 42
Sound 41
custom ICs
Ardbeg 20, 22
Combo 22
DFAC II 22
H
hard disk, connector 48
I, J
internal storage devices, bezel for
front drives 47
interrupts
for the pushbuttons 39
one-second 39
K, L
keyboard
power key 6, 16
reset and NMI functions 16
D
DFAC II custom IC 22
B
bezel, for front drives 47
block diagram 21
booting from CD-ROM 40
E
C
F
carrier for CD-ROM drive 50
CD-ROM booting 40
CD-ROM drive 48
audio signals from 51
bezel for 47
connector 48
mounting sled for 50
power for 50
SCSI ID number 51
CD-ROM formats 53
clock speed 20
features summary 2
floppy disk connector 12
floppy disk controller 20
FPU (floating-point unit) 20
expansion card. See PDS card
G
M, N
machine identification 38
master power switch 6
location of 4
MC68030 microprocessor
clock speed 20
signals on PDS connector 32
microphone
built-in 16
connector for 16, 41
power for 16
O
one-second interrupt 39
Open call 43
Gestalt Manager 38
GPi (general-purpose input)
signal 14, 22
55
I N D E X
P, Q
S
T, U
parameter RAM 22
PDS (processor-direct slot) 10, 34
PDS card 34
addresses 35
card select signal 35
compatibility with
Macintosh LC II 30
connector for 35
design guidelines 35
power, maximum 36
signal loading 32
PDS connector signals 32
power, safe shutdown 6
power button 6
power for CD-ROM drive 50
power for PDS card 36
power key 6, 16
power saver 7, 39
power switch 6
location of 4
pushbutton interrupts 39
Pushbutton register 39
pushbuttons
interrupts for 39
location of 3
screen control 5
sound level 16
Screen control panel 42
screen control pushbuttons 5
Screen driver
Control call 43
Open call 43
Status call 44
SCSI, bus termination 10 to 12
SCSI connector 10
SCSI controller 22
serial I/O controller 22
serial I/O ports 13
GPi signal on 22
modem power 14
sound
filters 23
input jack 16, 41
microphone 16
modes of operation 22
output jack 22
playthrough feature 22
pushbuttons 16
sample rates 23
sound circuits 22
Sound control panel 41
sound input jack 16, 41
sound output jack 22
standard abbreviations xi to xii
startup from CD-ROM 40
Status call 44
summary of features 2
System 7.1 40
system enabler 40
system software 40
termination, of the SCSI bus 10 to
12
automatic 11
R
RAM
address space 23
configurations 8
expansion 8
RAM SIMM 8
reactivating the screen 39
removing the logic board 4
56
V, W, X, Y, Z
VIA registers 20
video display
for Apple IIe card 5, 27
bits per pixel 6
dimensions 5
dimming by power saver 7
intensity of 5
timing 25
VRAM 6
video RAM. See VRAM
virtual memory 38
VRAM 25
expansion 6
SIMM 25
VRAM data bus 25
Figure 6-0
Listing 6-0
Table 6-0
Foldouts
6
062-0487-B
Expansion card design gu
FOLDOUT 1
062-0487-B
Expansion card componen
FOLDOUT 2
062-0487-B
Expansion card assembl
FOLDOUT 3