Radio Shack TRS-80 Model III - Page 82

TRS-80
MODEL
$PRCHAR
—
59/X003B
'
Output
a
Character
to the Printer
SPRCHAR
waits until the Printer is
available or until (BREAK) is pressed
. If (BREAK) is
pressed, SPRCHAR returns
to caller.
Entry
Conditions
A
=
ASCII character
Exit Conditions
DE is altered.
Sample Z-80 Programming
8356
216583
8357
7E
835
A
23
835 B
CD3B00
835E
FE0D
8360
20F7
8362
C3191A
8365
54
8382
0D
402D
00000
ASSEMBLY
00148
; PRINTER
DEMO
00149
00150 LOOPS
00151
00152
00153
00154
00155
00156
TXT4
00157
00158
LD
HL»TXT4
LD
A!
(HL)
INC
HL
CALL
PRCHAR
CP
0DH
JR
NZi LOOPS
JP
READY
DEFM
DEFB
'THIS
SENTENCE
0DH
END
(HL)=SAMPLE
TEXT
GET CHAR.
INTO
A
POINT
TO
NEXT
CHAR
PRINT
CHAR
IN
A
WAS IT
A
CARRIAGE
RETURN';
IF
NO,
GET
NEXT
CHAR.
IF
YES,
SUIT
WILL
BE
PRINTED'
ERRORS
$PRSCN—
473/X01D9'
Print
Entire Screen
Contents
This routine copies all
1024 characters from the screen to the printer.
If the printer
is
unavailable, it waits until the printer
becomes available. If
(BREAK) is pressed,
SPRSCN returns to the caller.
Entry Conditions
None
Exit Conditions
All
registers are altered.
72