Radio Shack CCR-81 Operation Manual

Computer Graphics
TRS-BO@
Operation Manual
,.....---..
~fiffif98
ADD HL,DE
~fiffif99
XOR
A
~fif1fif~
CP
(HL)
iEnd of buffer?
~fif1~l
JR
Z,EPRT
~fif1fif2
LD
C, (CTL)
~fif1fif3
CALL PRLINE
~fif1fi14
LD HL,2l4
fi1fi11fi1S
ADD HL,DE
iNext part of buffer
fi1fi1lfi16
EX DE,HL
~fif1fi17
JR PART
fi1fi1lfi18
EPRT
POP
BC
fi1fif1fi19
RET
fi1fif1lfi1
·
,
~fi111l PRLINE
EQU
$
iPrint a line. HL==>line to print
fi1fif1l2
PUSH DE
fi1fi1l13
PRL2
LD
A, (HL)
iB =
# characters to print
~fi1114
INC HL
iC =
EOL char (sent after line)
~fi1l1S CALL
3BH
iHL,
BC, AF, and DE used
fi1fif1l6
DJNZ PRL2
~fifl17 LD
A,C
~fifl18 OR
A
~fi1119
CALL NZ,3BH
fi1fif12fi1
POP
DE
fi1fifl2l RET
~
~fif122
·
,
fi1fi1l23
i
INITG -- Initialize
Model III Graphics
Board
fi1 fif12 4
·
,
~fifl2S
INITG
LD
A, lfi1H
fi1fi1126 OUT
(236),A
iTurn on port
fi1fifl27
LD BC,lS
~fif128 LD HL,DATA
fi1fi1l29
LOOP
LD A,B
iProgram CRTC chip for 8fi1 by 24
~fif13fi1
OUT (136) ,A
~fifl31 LD
A, (HL)
fi1fif132 OUT <l37),A
~fifl33 INC
HL
~fif134 INC
B
~fifl3S
LD A,B
~fif136 CP
C
fi1fi1l37 JR NZ,LOOP
~fif138 RET
~fif139
DATA
DEFB
99
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Radio Shack CCR-81 Specifications

General

Brand	Radio Shack
Model	CCR-81
Category	Desktop
Language	English