User`s guide

ManualsBrandsVector Graphic ManualsComputer equipmentExtended Systems Monitor

Vector

ZCB

Single

Board

Ca!puter

2.4.2

Address

mirroring

disable/enable

Jumper

area:

0

Comections

as

manufactured:

function

enabled:

pad 3

comected

to

pad

2

Function:

emulates

8080

address

mirroring:

8-bit

I/O

p::>rt

address

is

mirrored

on

the

high

a:3dress

bus

during

an

I/O

instruction.

Options:

To

disable

address

mirroring,

cut

the

jumper between

pads

3 and 2 and

jumper

1

and

2

together.

'!his

will

place

the

I/O

device

address

on

the

lower

half

of

the

address

bus

am

the

value

of

the

contents

of

the

accumulator

on

the

upper

half

of

the

address

bus

during

a

direct

I/O

instruction.

I:Uring

indirect

I/O

instructions

(including

block

noves),

the

value

of

the

contents

of

register

C

is

placed

on

the

lower

half

of

the

address

bus

(device

address)

while

the

value

of

the

contents

of

register

B

is

placed

to

the

upper

half

of

the

address

bus.

Rev.

l-B

6/11/80

2-9