Commodore Amiga A500 Product manual

Technical Reference Manual
0 Commodore

Commodore"Amiga"
AS00/AZ000
Technical Reference
Manual

COPYRIGHT
This manualiscopyright
0 1986. 1987 byCommodore-Amiga.Inc.All RightsReserved. Thisdocument
may not. in whole or part. be copied, photocopied, reproduced, translated or transferred to any
electronic medium or machine readable form without prior consent, in writing, from Commodore-
Amiga. Inc.
Amiga is a registeredtrademark ofCommodore-Amiga. Inc.
Commodore and CBM are registered trademarks ofCommodore Electronics Limited.
Hayes isa registeredtrademark of Hayes Microcomputer Products. Inc.
IBMisa registeredtrademark of International BusinessMachinesCorporation.
Maclntosh isa trademark ofApple Computer. Inc.
DISCLAIMER
THE INFORMATIONIS PROVIDED"AS IS" WITHOUT WARRANTY OF ANY KIND. EITHER EXPRESSEDOR
IMPLIED. THE ENTIRE RISK AS
TO THE ACCURACY OF THE INFORMATION HEREIN IS ASSUMED BY
YOU. COMMODORE-AMIGA DOES NOT WARRANT. GUARANTEE. OR MAKE ANY REPRESENTATIONS
REGARDING THE USE OF, OR THE RESULTS OF THE USE OF, THE INFORMATION IN TERMS OF
CORRECTNESS. ACCURACY. RELIABILITY, CURRENTNESS. OR OTHERWISE. IN NO EVENT WILL
COMMODORE-AMIGA. INC. BE LIABLE FOR DIRECT. INDIRECT, INCIDENTAL OR CONSEQUENTIAL
DAMAGES RESULTING FROM ANY DEFECT INTHE INFORMATION EVEN IF IT
HAS BEENADVISED OF
THE WSSlBlLlTY OF SUCH DAMAGES. SOME LAWSDO NOT ALLOW THE EXCLUSION OR LIMITATIONOF
IMPLIED WARRANTIES OR LIABILITIES FOR INCIDENTAL OR CONSEQUENTIAL DAMAGES. SO THE
ABOVE LIMITATIONOR EXCLUSION MAY NOT APPLY.
Schematicsrepresent current machinewhich is subjecttochange without notice.
Credits
The material for this manual was produced by Engineering, Documentation,
and Technical Support staff at Commodore West Chester. Commodore
Braunschweig, and Commodore-Amiga. Individuals contributing major por-
tions of information and input are Dave Haynie, Jeff Porter, Phil Lindsay,
Carolyn Scheppner, Lisa Siracusa, George Robbins, Andy Finkel, Eric Cotton,
Jeff Boyer. Steve Ahlbom, Steve Beats, Dieter Preiss, Bernd Assmann, and
Torsten Burgdorf.
This manual was compiled and edited by Steve Finkel.
Manual design by Jo-Ellen Temple and Wilson Harp.

AZOOO/AS00 Technical Reference Manual
Table
of Contents
Section 1 Summary of Differences
Section 2 System Block Diagrams
Section 3 Amiga Expansion
3.1
Designing hardware for the Amiga Expansion Architecture
3.2 Driver Documentation
3.3 Software for Amiga Expansion
3.4 Amiga Expansion Connectors
100Pin
86 Pin
Video Slot
Section 4 PC Bridgeboard
4.1
Description of the PCIXT emulator for the Amiga 2000
4.2 BlOS entry points
4.3 Janus library
Section S Amiga Hard DisWSCSl Controller
Section6 Custom Chips
Fat Agnus Chip
8520Chip
Section 7 Miscellaneous Hardware Information
7.1 ClocWcalendar registers
7.2 Power budgets
7.3 A2000 PAL equations
7.4 B2000 Jumpers
Appendix A. Diagrams
A-l
Backplane Example
A-2 PIC Example
A-3 A500 Exterior (86-pin expansion connector)
A-4 Amiga 2000 Expansion Board Layout
A-S Amiga 2000 Form Factor
A-6 Amiga 2000Video Card
A-7 86-Pin Slot Expansion Board
A-8 A2000lB2000 Keyboard Connector Pinout
A-9 Amiga 50012000 Mouse Diagram and Pinout
Appendix B. Schematics
A2000 Schematics
B2000 Schematics
A500 Schematics

Section 1
Summary of Differences
This manual presents technical documentation for three different
Amiga models, comparing them tothe original Amiga, referred toas
model A1 000. Technical information included in this manual
is rel-
evant for the following Commodore Amiga models:
the Amiga 500 (A500), a low-cost version of the origi-
nal Amiga computer, software-compatible with the
A1 000. Unlike the A1
000, the A500 has an integrated
keyboard, provision for internal memory expansion up
to 1 megabyte, new-style hardware connectors, and
Kickstart code in
ROM.
Two versions of the Amiga 2000:
theA2000 is software-compatiblewith theA1 000 and
has internal slots, real time clocWcalendarand new-
style hardware connectors.
the B2000,the cost-reduced version of the Amiga
2000,features some different custom chips, but is
otherwise similar tothe A2000.
The B2000 is still under development, and the information present-
ed in this document is subject tochange. The information included on
the B2000 is intended to aid developers in designing software and
peripherals that are applicable for both the current and upcoming
version of the Amiga 2000.
Unless differences are specifically noted, information presented for
the A2000 also holds true for the B2000. The differences between
the two Amiga 2000 models are mainly hardware differences which
will affect peripheral design, but not the way the computersfunction
with software. Section 2 contains system block diagrams for all
three new Amiga models.
KICKSTART IN ROM
Both the Amiga 2000and the Amiga 500feature version 1.2 of
lckstart built into ROM. Kickstart 1.2 (currently version 33.180)
boots automaticallywhen the Amiga is turned on.

EXTRA KEYS ON THE
Both the Amiga 2000and 500 feature 94-key keyboards, as com-
KEYBOARD
pared to the A1 000's 89-key keyboard. (The European versions of
thekeyboards have
96 keys.) The new keys areall located on the nu-
meric keypad, and include:
KEY
SCAN CODE
Left parentheses
( $5A
Right parentheses 1 $5B
Slash
I $5C
Asterisk
* $5D
Plus
+ $5E
In PC mode on the Amiga 2000 (using a Bridgeboard), these keys
assume typical PC functions, including Number lock (left parenthe-
sis), Print screen (asterisk) and Scroll lock (right parenthesis).
On some keyboards, the left Amiga key has been replaced by the
Commodore key. This key performs identically in either case.
RAW KEY CODES ON
Keyboard Layout Showing Raw Key Codes
THEKEYBOARD
Figure 1 .l Key Codes
Note: On the U.S. keyboard, the keys with codes 44 and 60 are
extended toinclude the European keys with codes 2Band
30.
respectively. Also note that England uses the U.S. rather than
the European keyboard, but not the U.S. keymap.
See Table 1 - 1 atthe end of this section for a table of the raw key
codes.

EXTERNAL SYSTEM v0
This section describes each I10 interface in detail, and some of the
tradeoffs made with respect to
AI 000compatibility.
The Amiga 2000and Amiga
500 have differences in the serial and
parallel ports from the Amiga 1000,the main difference being
changes in the sex of each port (changingthe serial tofemale and the
parallel to male),which allowsthe new Amigas to use standard inter-
face cables.
RS232 and MIDI Port
The RS232 connector on the A500 and A2000 is form fit and func-
tion identical toa Commodore PC-10120with a fewexceptions.
This
is the OPPOSITE sex connector from the A1000. The connector
is a shielded male DB25P connector. The A1 000supplies various
non-standard RS232 signals on the DB25 connector. These non-
standard signals were removed wherever possible. The RS232 con-
nectar is NOT physically compatible with some MIDI interfaces but is
compatible with the ~miga~odem/1200RS (model 1680).Below is
a comparison chart between the RS232 standard,a Hayes Smart-
modem standard, the A1 000 RS232, and the new Amiga 50012000
RS232 connector.
AS001
PIN RS232 A1000 A2000 PC10 HAYES@ DESCRIPTION
GND
TxD
RxD
RTS
CTS
DSR
GND
DCD
-
-
S.SD
S.CTS
S.T X D
TxC
S.R X D
RxC
-
S.RTS
DTR
SQD
R I
SS
TxCl
-
Frame ground
Transmit Data
Receive Data
Request to send
Clear to send
Data set ready
Signal ground
Carrier detect
+ 12volt power
- 12volt power
Audio output
Speed Indicate
GND
TxD
RxD
RTS
CTS
DS
R
GND
DCD
GND
TxD
RxD
RTS
CTS
DSR
GND
DCD
+ 12v
- 12v
AUDO
-
CND
TxD
RxD
RTS
CTS
DSR
CND
DCD
+ 12v
- 12v
GND
TxD
RxD
-
CTS
DSR
GND
DCD
-
- 5Vdc
AUDO
AUDl
EB
INTZ*
- 5 volt power
Audio output
Audio input
Port clock 71
6KHz
Interrupt IineJAudio input
AUDl
DTR
+ 5Vdc DTR DTR
-
DTR Data terminal ready
+ 5 volt power
Ring indicator
+ 12volt power
3.58MHz clock
Buffered system reset
C2*
RESB*

As you will notice, the A500 and 2000deletes clocks and interrupt
lines from the A1 000. The
+ l - 5Vdc and reset lines are also de-
leted. The
+ 1 - 12Vdc lines are identical to a PC10120.
The following signals (formerlyon the RS232 connector)can
be found
on other connedors:
ResB = parallel connector
C2
= video connector
Centronics Port
The Centronics port also has some non-standard signals. Below is a
table comparing the A1
000 Centronics port with the A500lA2000
Centronics port. Again,this is the opposite sex from the A1 000
and the same sex connector as an IBMB-PC (i.e.,a female DB25
connector).
PIN A1 000 ASOO/AZOOO PC1 0
Video Output
DRDY*
Data 0
Data 1
Data 2
Data
3
Data 4
Data 5
Data 6
Data 7
ACK*
BUSY (data)
POUT(clk)
SEL
CND
CND
CND
CND
GND
+ 5v
NC
Reset*
STROBE*
Data
0
\ Data 1
j Data 2
Data
3
k; \
\ Data 7
ACK*
k. BUSY
h POUT
. SEL
%*A + 5v pullup
NC
RESET*
GND
GND
GND
GND
GND
STROBE*
Data
0
Data 1
Data 2
Data
3
Data 4
Data 5
Data 6
Data 7
ACK*
BUSY
POUT
SEL
AUTOFDXT*
ERROR*
INIT*
SLCT IN*
GND
GND
GND
GND
The A500 and A2000, like the A1 000, use a DB23 video connector.
This 23pin connector contains all the signals necessary toworkwith
a Genlock, but the current Genlock will need
to be redesigned in or-
der to meet the physical requirements of the
A500 and A2000, in-