6520 PIA pinout

DIP-40. Keyboard, cassette 1, IEEE-488 data (PET)

Two 8-bit ports with handshake lines. PIA1 at $E810: keyboard rows, cassette 1, screen-retrace IRQ, diagnostic sense. PIA2 at $E820: IEEE-488 data port. Dead keyboard points at PIA1; no disk or IEEE-488 points at PIA2 or the VIA.

Open the interactive PIA pinout

Pins

Pin	Name	Type	Signal
1	Vss	ground	0 V.
2	PA0	io	Port A bit 0.
3	PA1	io	Port A bit 1.
4	PA2	io	Port A bit 2.
5	PA3	io	Port A bit 3.
6	PA4	io	Port A bit 4.
7	PA5	io	Port A bit 5.
8	PA6	io	Port A bit 6.
9	PA7	io	Port A bit 7.
10	PB0	io	Port B bit 0.
11	PB1	io	Port B bit 1.
12	PB2	io	Port B bit 2.
13	PB3	io	Port B bit 3.
14	PB4	io	Port B bit 4.
15	PB5	io	Port B bit 5.
16	PB6	io	Port B bit 6.
17	PB7	io	Port B bit 7.
18	CB1	io	Port B handshake / interrupt input (active edge set in the control register).
19	CB2	io	Handshake, port B.
20	Vcc	power	+5 V supply.
21	R/W	ctrl	Read/write from the CPU.
22	CS0	ctrl	Chip select 0, active HIGH.
23	/CS2	ctrl	Chip select 2, active LOW.
24	CS1	ctrl	Chip select 1, active HIGH.
25	Φ2 (E)	clock	Phase 2 (E) clock from the CPU.
26	D7	data	Data bus bit 7.
27	D6	data	Data bus bit 6.
28	D5	data	Data bus bit 5.
29	D4	data	Data bus bit 4.
30	D3	data	Data bus bit 3.
31	D2	data	Data bus bit 2.
32	D1	data	Data bus bit 1.
33	D0	data	Data bus bit 0.
34	/RES	ctrl	Reset. LOW clears the PIA.
35	RS1	addr	Register select bit 1.
36	RS0	addr	Register select bit 0.
37	/IRQB	ctrl	Interrupt request, port B.
38	/IRQA	ctrl	Interrupt request, port A.
39	CA2	io	Handshake line, port A.
40	CA1	io	Interrupt input, port A.

Fitted in

PET / CBM
Atari 400 A102 (motherboard)
Atari 800 A102 (motherboard)
Atari 600XL
Atari 800XL U23
Atari 130XE U23

Sources

MCS6520 Peripheral Adapter data sheet, p. 1 pin configuration (GIF scans)