The Programmer's Guide to TRSDOS Version 6 - Tim Mann's Home ...

8.16 DMP-500 BOLDFACE Filter Illustrated
;BOLDFACE/ASM - FILTER to invoke boldfacing on DMP-500 - 03/20/83
TITLE ''
;*****
; This filter uses two trigger toggle characters to turn
; on and off the boldface mode of the DMP-500 printer.
; One character called TOGGLE (defaults to tilde) will
; toggle on/off boldface and output a space in lieu of
; the toggle character. This is useful to maintain right
; justification. The other character called NULL (defaults
; to DELETE, X'7F') toggles the boldface mode but causes
; no character to be sent in lieu of the toggle character.
; The boldface mode is automatically turned off when a
; carriage return (X'0D') is sensed.
;*=*=*
COM ''
;*=*=*
LF EQU 10
CR EQU 13
ESCAPE EQU 27
BOLDON EQU 31
BOLDOFF EQU 32
@CHNIO EQU 20
@HIGH$ EQU 100
@DSPLY EQU 10
@FLAGS$ EQU 101
@PARAM EQU 17
@LOGOT EQU 12
;
ORG 3000H
BEGIN PUSH DE
POP IX ;Get DCB into IX
LD (MODDCB),DE ;Stuff DCB pointer
PUSH HL ;Save INBUF$ pointer
LD HL,HELLO$
LD A,@DSPLY
RST 40
POP HL ;Rcvr INBUF$ pointer
;*=*=*
; Check if entry from SET command
;*=*=*
LD A,@FLAGS$ ;Get flags pointer into IY
RST 40
BIT 3,(IY+'C'-'A') ;System request?
JP Z,VIASET
;
LD DE,PRMTBL$ ;Grab any user parms
LD A,@PARAM
RST 40
JP NZ,PRMERR
;*=*=*
; Transfer requested TOGGLE e/w space to filter
;*=*=*
LD A,(TRESP) ;Ck if any entry
LD B,A
TOGGLE LD HL,7EH ;Set default to TILDE
LD A,(HL) ;P/u assumed string
BIT 5,B ;String entry?
JR NZ,TSTUF
LD A,L ;P/u hex or dec entry
BIT 6,B ;Error if switch entry
JP NZ,PRMERR
TSTUF LD (TILDE1+1),A ;Stuff it in there
LD (TILDE2+1),A
;*=*=*
; Transfer requested toggle w/o space to filter
;*=*=*
LD A,(NRESP) ;Ck if any entry
LD B,A
NULL LD HL,7FH ;Set default to DELETE
LD A,(HL) ;P/u assumed string
BIT 5,B ;String entry?
JR NZ,NSTUF
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