Memory and I/O Capability
ZT8809A REV. A
W2
W3
W4
W5
W6
W7
W8
W12
W9
W10
W11
W64
W65
W63
W62
W60
W61
W51
W52
W53
W54
W55
W56
W57
W58
W59
W50
W66
W47
W49
W48
W37
W33
W34
W36
W35
W38
W40
W39
W43
W46
W13
W14
W15
W16
W17
W18
W19
W20
W21
W22
W23
W24
W25
W26
W27
W28
W29
W30
W31
W32
W44
W45
LPT
INTERRUPTS
TIMER
COUNTER
COM2
COM1
W67
W68
W1
AB
B
A
B
A
B
A
A B
A B
A B
B
A
AB
A
B
A
B
A
A
B
A
B
128K RAM
256K EPROM
512K RAM
Not Installed
Figure 5–4. STD DOS With 640K RAM Jumper Configuration.
5-7