NAM PPGTST-1

 ORG $0020
 LDX #CLRSCN
 JSR PDATA1
START LDA A #$3D 
 LDX PARADR 
 LDA B #$00 
 STA B 2,X
 STA A 3,X
LOOP1 LDA A 3,X
 AND A #$80 
 BEQ LOOP1
 LDA A 2,X  
 TAB
 AND A #$80 
 BNE LOOP1 
 AND B #$7F 
 STA B LOPOS
LOOP2 LDA A 3,X 
 AND A #$80 
 BEQ LOOP2
 LDA A 2,X 
 TAB
 AND A #$80
 BNE SKIP1
 LDX ERRSTR
 JSR PDATA1
 BRA LOOP1
SKIP1 AND B #$7F
 STA B HIPOS
 LDA A LOPOS 
SKIP2 JSR OUTHL
 LDA A LOPOS 
 JSR OUTHR
SKIP3 JSR OUTS 
 LDA A HIPOS
SKIP4 JSR OUTHL 
 LDA A HIPOS 
 JSR OUTHR
SKIP5 LDX #CRLF 
 JSR PDATA1 
 LDX PARADR 
 BRA LOOP1
LOPOS FCB $00
HIPOS FCB $00

CLRSCN FCB $0D,$0A,$10,$16,$00,$04

PARADR EQU $A002
CRLF FCB $0D,$0A,$00,$00,$00,$04
ERRSTR FCC /SEQUENCE ERROR/

 FCB $04
 ORG $A048
 FDB $20
 ORG $A002
 FDB $801C
PDATA1 EQU $E07E
OUTHL EQU $E067
OUTHR EQU $E06B
OUTS EQU $E0CC 
END