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Sharp MZ-3500 User Manual

Page 73

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7-6. I/O port map

8255 ON SUB CPU BUS

M / 3500

PA7

N.

DATAS '

PA6

DATAT

i‘A5

DATAS

PA4

DATA 5

PA3

Output

DATA4

8255

PA2

DATAS

Printer

chip address(CX)11 /xxxx]

oc PAI

DATA2

>

PAO

>

DATAI

PC7 OBF outpu

ACK T-SET

Group A: Mode 1

Group B: Mode 0

PC6 ACK inputi

ACK

PC 5

N

STROBE

^

PC4

MUS 1 C , sustain

PC3

INTR

NOT USE

PC 2

N

ACKC

'

PCI

STC

Keyboard

PCO

DC

PB7

P/M

CG selection

O

PB6

SRDY

Sub CPU READY

oc

T3

PB5

Output

CLK

ro

PB4

Din

PB3

C2

Clock

PB2

CI

PBl

CO

PBO

STRB

-

INPUT PORTC74LS2443

CDS7 :

HLT KEY

74LS244

CDS6D

STK D

Keyboard

port addressÌOlOO/xxxx]

CDS5D

DK

J

CDS4D

PDTR -1

CDS33

PE

Printer

CDS23

BUSY J

CDSl 3

Reads the 8255 OBF (PC7)

COSO 3

output or timer output.

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