Planck 6502 expansion bus pinout signals @ PinoutGuide.com

at the backplane

This is the expansion but pinout for the Planck 6502 open hardware, extensible retro computer.

Pin Number	Pin Name	Description
1	A0	Processor address bus pin 0
2	D0	Processor data bus pin 0
3	A1	Processor address bus pin 1
4	D1	Processor data bus pin 1
5	A2	Processor address bus pin 2
6	D2	Processor data bus pin 2
7	A3	Processor address bus pin 3
8	D3	Processor data bus pin 3
9	A4	Processor address bus pin 4
10	D4	Processor data bus pin 4
11	A5	Processor address bus pin 5
12	D5	Processor data bus pin 5
13	A6	Processor address bus pin 6
14	D6	Processor data bus pin 6
15	A7	Processor address bus pin 7
16	D7	Processor data bus pin 7
17	A8	Processor address bus pin 8
18	EX0	Extra pin for future use or for communication between expansion cards
19	A9	Processor address bus pin 9
20	EX1	Extra pin for future use or for communication between expansion cards
21	A10	Processor address bus pin 10
22	SLW	Used by slow peripherals to request a slower clock speed, active low.
23	GND	Ground
24	VCC	Positive voltage
25	VCC	Positive voltage
26	GND	Ground
27	A11	Processor address bus pin 11
28	SS	An expansion card is selected. Used by the processor card to disable it's built-in ram and ROM, active low
29	A12	Processor address bus pin 12
30	INH	When this is active (low), processor card RAM and ROM are disabled
31	A13	Processor address bus pin 13
32	SEL	Used by the backplane to signal to expansion cards when they should activate, active low
33	A14	Processor address bus pin 14
34	L1	Connected to one of the backplane LEDs
35	A15	Processor address bus pin 15
36	L2	Connected to one of the backplane LEDs
37	RDY	Processor I/O pin. When low, the processor waits in it's curent state
38	L3	Connected to one of the backplane LEDs
39	BE	Processor input pin. when low the processor releases the bus
40	L4	Connected to one of the backplane LEDs
41	CLK	Main computer clock. Can be stretched or not depending on the state of the SLOW signal.
42	CLK_12M	Stable clock for e.g. VIA timers. Not connected to slot 0
43	R/W	CPU read / write pin
44	EX2	Extra signal 2. Not connected to slot 0
45	IRQ	This goes low when an interrupt request has occured, active low
46	EX3	Extra signal 3. Not connected to slot 0
47	SYNC	CPU output. Indicates when the CPU is fetching an opcode
48	SIRQ	Used by expansion cards to signal an interrupt request to the processor board, active low
49	RST	Reset signal trigered by the button on the backplane, active low
50	NMI	non maskable interrupt signal trigered by the button on the backplane, active low