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Rana Systems Elite Series User Manual

Page 186

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ELITE SERIES USER MANUAL

THEORY OF OPERATION

Select Bank

TXA

Build $Cn00 address

LSR

to access controller

LSR

slot dependent PROM.

LSR

ORA #$CO

STA ZPAGE+ 1

LDY #$OO

STY ZPAGE

LDA $CFFF

Map out other boards

LDA (ZPAGE),Y

Map in Elite Controller

LDY #BANK

Select Bank 0/1

STA $C800,Y

LDA $CFFF

Map out Elite Controller

Read a Byte

READ LDA

$CO8C,X

BPL READ

N O T E : $CO8E,X must already have been accessed to

assure Read mode. The loop is necessary to as—

sure that the accumulator will contain valid

data. If the data latch does not yet contain

valid data, the high bit will be zero.

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