Sharp MZ-80B - Page 60

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The control functions of each port are listed below:
Port A
Port
Active
Control function
terminal
A7
H Assigns addresses $DOOO - $FFFF to V-RAM.
A6
H
Assigns addresses $50000 - $7FFF to V-RAM.
As
H
Changes screen to 80-character mode (L: 40-character mode).
A4
L
Turns all key strobe signals to L.
A3
11 Output strobe signals for keyboard scan.
A2
AI
Ao
Port B
Port
Active
Control function
terminal
B7
B6
Bs
B4
> Data inputs for keyboard scan.
B3
B2
B1
Bo
I-'