Commodore Computers 1581 - 6502 CPU Overview

1581 SERVICE MANUAL
6502 MICROPROCESSOR
Features of 6502
65K Addressable Bytes of Memory (A0-A15)
TR(5 Interrupt
On-the-chip Clock
TTL Level Single Phase Input
RC Time Base Input
Crystal Time Base Input
SYNC Signal
(can be used for single instruction execution)
RDY Signal
(can be used to halt or single cycle execution)
Two-Phase Output Clock for Timing of
Support Chips
NMT Interrupt
vss-
RDY-
Trq-
N.C.-
NMI-
SYNC-
VCC-
AO-
A1-
A2-
A3-
A4-
A5-
A6-
A7-
A8-
A9-
A1O-
A11-
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
40
39
38
37
36
35
34
33
32
6502 3-|
/iPRO- 30
CESSOR 29
28
27
26
25
24
23
22
21
RES
02(OUT)
S.O.
N.C.
N.C.
R/W
DO
D1
D2
D3
D4
D5
D6
D7
A15
A14
A13
A12
VSS
ADDRESS J
BUS A
r
A0 -«—
A1 -«—
A2 -*-
A3 ^~
A 4 -<—
A5 -*—
A6 -*-
A7 **-
A8 -*—
A9 ^_
A10 **—
A11 -«—
A12 -*—
A13 -«—
A14 -<—
A15 -<—
6512,13,14,15
6502.3.4.5,6.7