Radio Shack TRS-80 Model 3 - Page 86

TRS-80 MODEL III
Exit Conditions
DE is altered.
Sample Z-80 Program
TERMINAL PROGRAM FOR DEMO OF RS-232-C CALLS, $KBCHAR AND $VDCHAR
ASSUME 16888 & 16B89 CONTAIN THE PROPER INITIALIZATION VALUES
B32C
8T2D
B330
83:"~,3
B336
8 ,3:.3 r::;
833B
833D
B3
L
.0
8343
B346
B3'+9
E1.34 A
834C
B3
L
.E
B351
8353
AF
3:2FA41
CD5A00
CDC90i
CD2B00
FE(2)0
2806
CD3:3(2)(2)
CD5500
:21EB41
CD5000
lE
FE00
:28E8
CD3300
i8E3
C3191A
00127
00128
00129
(2)0130
00131
00132
00133
(2)013'+
00135
00136
00137
00138
00139
00140
00141
00142
00U.3
00144
00145
00146
00147
~{EYIN
RSIN
XOR
LD
CALL.
CALL
CALL
CP
JR
CALL
CALL
LD
CALL
LD
CP
,JR
CALL
JR
JP
A
(16B90), A
RSINIT
VDCLS
~{BCHAR
o
Z,RSIN
VDCHAR
RSTX
HL,16872
RSRCV
A, (HU
Q)
Zd{EYIN
VDCHAR
.\EYIN
READY
ZERO A TO SEL.ECT "DON'T WAIT"
CHECK ~\EYBOARD
IF NOTHING, CHECK RS232
SELF·-ECHO
SEND IT TO RS232
(HL)=CHAR.INPUT BUFFER
CHECK FOR RS232 INPUT
GET BUFFER CONTENTS
IF NOTHING, CHECK KB
ELSE DISPLAY IT
CHECK .\B
RETURN TO BASIC
$RSRCV -80/X'0050'
Receive a Character from the RS-232-C Inter(ace
If RS-232-C Waitis enabled, this routine waits for a characterto be received, or until
(BREAK) is pressed.
If Wait is notenabled, itreturns whether or not a characteris received.
EntryConditions
None
ExitConditions
(16872) = Characterreceived. Zero indicates no character.
DE is altered.
SampleZ-80 Programming
See $RSINIT.
12/18