RetroWiki

Amiga Bus

Here is some data on the Amiga's bus. Since I'm gathering enough data to build a Zorro II card I figured I could consolidate it and share it.

On the A2000

pin1 from the underside, where the pokeys poke through, is top right
pin1 from the top where the card goes in is top left

PCB Label	Slot Number	Type	Part Number	Notes
CN600	na	CPU slot	Foxconn ES04306	86 pins
CN601	5	Zorro II	Foxconn ES05006	far left
CN602	4	Zorro II	Foxconn ES05006	2nd from left
CN603	3	Zorro II	Foxconn ES05006	middle
CN604	2	Zorro II	Foxconn ES05006	2nd from right
CN605	1	Zorro II	Foxconn ES05006	far right
CN700	na	8 bit PC		far left
CN701	na	8 bit PC		2nd from left
CN702	na	8 bit PC		2nd from right
CN703	na	8 bit PC		far right
CN704	na	16 bit PC	Foxconn ES01806 or 530843.3	far left, empty, no connector soldered
CN705	na	16 bit PC	Foxconn ES01806 or 530843.3	2nd from left, empty, no connector soldered
CN706	na	16 bit PC	Foxconn ES01806 or 530843.3	2nd from right, flows down to Zorro slot 5
CN707	na	16 bit PC	Foxconn ES01806 or 530843.3	far right, flows down to Zorro slot 4

Bus

This is a popular copy of the pin out of the Amiga Bus, The A2000 and A3000 use a 100pin edge connector. This is a standard connector. If you can find one for a PC (IBM clone) it will work in the Amiga.

Why no reference to A4000? I know everyone wants one, but, the A3000 was the peak for me. If you want to donate me an A4000 I'll write up notes for it.

Pin	A500	A1000	A2000	A2000B	Name	Description
1	X	X	X	X	GND	Ground
2	X	X	X	X	GND	Ground
3	X	X	X	X	GND	Ground
4	X	X	X	X	GND	Ground
5	X	X	X	X	+5V	+5 Volts DC
6	X	X	X	X	+5V	+5 Volts DC
7	X	X	X	X	n/c
8	X	X	X	X	-5V	-5 Volts DC
9	X	X			n/c
9			X	X	28CLOCK	28MHz Clock
10	X	X	X	X	+12V	+12 Volts DC
11	X	X			n/c
11			X	X	/COPCFG	Configuration Out
12	X	X	X	X	CONFIG IN	Grounded
13	X	X	X	X	GND	Ground
14	X	X	X	X	/C3	C3 Clock
15	X	X	X	X	CDAC	Clock
16	X	X	X	X	/C1	C1 Clock
17	X	X	X	X	/OVR
18	X	X	X	X	RDY	Ready
19	X	X	X	X	/INT2	Interrupt 2
20	X*	X			/PALOPE	* This signal is NC on a A500 with a Gary Chip
20			X		n/c
20				X	/BOSS
21	X	X	X	X	A5	Address 5
22	X	X	X	X	/INT6	Interrupt 6
23	X	X	X	X	A6	Address 6
24	X	X	X	X	A4	Address 4
25	X	X	X	X	GND	Ground
26	X	X	X	X	A3	Address 3
27	X	X	X	X	A2	Address 2
28	X	X	X	X	A7	Address 7
29	X	X	X	X	A1	Address 1
30	X	X	X	X	A8	Address 8
31	X	X	X	X	FC0	Processor status 0
32	X	X	X	X	A9	Address 9
33	X	X	X	X	FC1	Processor status 1
34	X	X	X	X	A10	Address 10
35	X	X	X	X	FC2	Processor status 2
36	X	X	X	X	A11	Address 11
37	X	X	X	X	GND	Ground
38	X	X	X	X	A12	Address 12
39	X	X	X	X	A13	Address 13
40	X	X	X	X	/IPL0
41	X	X	X	X	A14	Address 14
42	X	X	X	X	/IPL1
43	X	X	X	X	A15	Address 15
44	X	X	X	X	/IPL2
45	X	X	X	X	A16	Address 16
46	X	X	X	X	/BEER	Bus Error
47	X	X	X	X	A17	Address
48	X	X	X	X	/VPA
49	X	X	X	X	GND	Ground
50	X	X	X	X	ECLK	E Clock
51	X	X	X	X	/VMA
52	X	X	X	X	A18	Address 18
53	X	X	X	X	RST	Reset
54	X	X	X	X	A19	Address 19
55	X	X	X	X	/HLT	Halt
56	X	X	X	X	A20	Address 20
57	X	X	X	X	A22	Address 22
58	X	X	X	X	A21	Address 21
59	X	X	X	X	A23	Address 23
60	X	X			/BR
60			X	X	/CBR
61	X	X	X	X	GND	Ground
62	X	X	X	X	/BGACK
63	X	X	X	X	D15	Data 15
64	X	X			/BG
64			X	X	/CBG
65	X	X	X	X	D14	Data 14
66	X	X	X	X	/DTACK
67	X	X	X	X	D13	Data 13
68	X	X	X	X	R/W	Read/Write
69	X	X	X	X	D12	Data 12
70	X	X	X	X	/LDS
71	X	X	X	X	D11	Data 11
72	X	X	X	X	/UDS
73	X	X	X	X	GND	Ground
74	X	X	X	X	/AS
75	X	X	X	X	D0	Data 0
76	X	X	X	X	D10	Data 10
77	X	X	X	X	D1	Data 1
78	X	X	X	X	D9	Data 9
79	X	X	X	X	D2	Data 2
80	X	X	X	X	D8	Data 8
81	X	X	X	X	D3	Data 3
82	X	X	X	X	D7	Data 7
83	X	X	X	X	D4	Data 4
84	X	X	X	X	D6	Data 6
85	X	X	X	X	GND	Ground
86	X	X	X	X	D5	Data 5

Memory Map

This is a grab of some data found on the Interwebs. This shows both Zorro II and III details

Address	Size [MByte]	Description
0x0000 0000	2.0	Chip memory
0x0020 0000	8.0	Zorro II memory expansion space
0x00A0 0000	1.5	Zorro II I/O expansion space
0x00B8 0000	3.0	A2000 motherboard register space
0x00E8 0000	0.5	Zorro II I/O
0x00F0 0000	1.0	Motherboard ROM
0x0100 0000	112.0	A3000 motherboard space
0x0800 0000	128.0	32-Bit memory expansion space
0x1000 0000	1792.0	Zorro III expansion space
0x8000 0000	2032.0	Reserved
0xFF00 0000	64 KB	Zorro III Configuration unit
0xFF01 0000	16.0	Reserved
0xFFFF FFFF	16.0	Reserved
		Who can count hexadecimal? is 0xFF01 0000 to 0xFFFF FFFF equal to 16MB? I'm not clear if the last fields are a beginning and end range or two ranges each at 16MB

Power

This appears to the power that can be drawn through the bus. Nowadays, the only thing people care about is the 5v.

Volt	Ampere
+5	2.0
-5	< 0.3
+12	< 8.0
-12	< 0.3

CPU Slot

Amiga 2000 CPU Slot Pinout

Pin	Name
1	gnd
2
3	gnd
4
5	+5V
6	+5V
7	exp
8	-5V
9	28 MHz
10	+12V
11	COPFG*
12	CONFIG*
13	gnd
14	C3*
15	CDAC
16	C1*
17	OVR*
18	XRDY
19	INT2*
20	BOSS*
21	A5
22	INT6*
23	A6
24	A4
25	gnd
26	A3
27	A2
28	A7
29	A1
30	A8
31	FC0
32	A9
33	FC1
34	A10
35	FC2
36	A11
37	gnd
38	A12
39	A13
40	ILP0*
41	A14
42	ILP1*
43	A15
44
45	A16
46	BERR*
47	A17
48	VPA*
49	gnd
50	E
51	VMA*
52	A18
53	RES
54	A19
55	HLT*
56	A20
57	A22
58	A21
59	A23
60	CBR*
61	gnd
62	BGACK*
63	PD15
64	CBG*
65	PD14
66	DTACK*
67	PD13
68	PRW*
69	PD12
70	LDS*
71	PD11
72	UDS*
73	gnd
74	AS*
75	PD0
76	PD10
77	PD1
78	PD9
79	PD2
80	PD8
81	PD3
82	PD7
83	PD4
84	PD6
85	gnd
86	PD5

Table of Contents

Amiga Bus

Bus

Memory Map

Power

CPU Slot

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