;
 ORG $2000
;LOW LEVEL DISK ACCESS
;SECTOR READER
;WRITTEN BY THOMAS EVERETT
;FEB 17-19, 1989
;APR 2, 1989
;STARTED REVISION 2
;APRIL 26, 1989
;CONTINUED WORK
;JULY 18, 1989
;NOV 3, 1989
;APRIL 1,1990
;IT WILL RETURN TO BASIC
;PRESSING ESC. FROM
;THE EDITOR PUTS YOU
;IN THE ROUTINE TO SELECT
;TRK., SEC. ESC. WILL THEN
;EXIT THE PROGRAM
;
;ALL ROUTINES MUST EXIT
;WITH SLOT IN X
;
; ZERO PAGE VARIABLES
;
; NEXT 2, GENERAL PURPOSE
; SCRATCH VARIABLES
ST1 EQU $06
ST2 EQU $07
ST3 EQU $08
ST4 EQU $09
PT1L EQU $19
PT1H EQU $1A
; NEXT TWO VARIABLES
; ARE SCRATCH FOR READ
RDSC1 EQU $1B
RDSC2 EQU $1C
SLOT1 EQU $1D
; FOLLOWING VARIABLES
; (USES APPLESOFT'S SPACE)
; ARE SECTORING BYTES
;
; ADDRESS FEILD
AP1 EQU $60
AP2 EQU $61
AP3 EQU $62
AE1 EQU $63
AE2 EQU $64
AE3 EQU $65
; DATA FEILD
DP1 EQU $66
DP2 EQU $67
DP3 EQU $68
DE1 EQU $69
DE2 EQU $6A
DE3 EQU $6B
;
; $300 PAGE VAIABLES
;
TRK  EQU $300
UTRK EQU $301
DTRK EQU $302
SLOT EQU $303
DSEC EQU $304
USEC    EQU $305
SECB1   EQU $306
SECB2 EQU $307
CX    EQU $308
CY EQU $309
POS EQU $30A
NOBYTS EQU $30B
VOL EQU $30C
;
TOPBUFL EQU $320
TOPBUFH EQU $321
BOTBUFL EQU $322
BOTBUFH EQU $323
WRTRLOC EQU $324
RDTRLOC EQU $325
BUF1LOC EQU $326
BUF2LOC EQU $327
BUF3LOC EQU $328
BUF4LOC EQU $329
;
BSTR EQU $330
;
; MONITOR VARIABLES
;
 
KEYBD EQU $C000
STROBE EQU $C010
SPKR EQU $C030
PAGE2 EQU $C055
DISSEM EQU $FE5E
NORMAL EQU $FE84
INVERSE EQU $FE80
SAVEREG EQU $FF4A
GETREG EQU $FF3F
PRTAX EQU $F941
DELAY EQU $FCA8
PRSPC EQU $F948;3 SPACES
;PRBL2 IS PART OF PRSPC
PRBL2 EQU $F94A
HOME EQU $FC55
VTAB EQU $FC22
CROUT EQU $FD8E
COUT EQU $FDED
KEYIN EQU $FD0C
DIGOUT EQU $FDE3
MONITOR EQU $FF69
PRHEX  EQU $FDDA
BASIC EQU $3D0
;
; BUFFERS
;
WBUFFD EQU $3029
; WRITE TRANSLATE TABLE
; POINTER IS WRTRLOC
; SOURCE IS WRTRANS
;
RBUFFD EQU $3100
; READ TRANSLATE TABLE
; POINTER IS RDTRLOC
; SOURCE IS RDTRANS
;
BUFF1 EQU $3200
; PRIMARY BUFFER
; POINTER IS BUF1LOC
;
BUFF2 EQU $3300
; SECONDARY BUFFER
; POINTER IS BUF2LOC
;
BUFF3 EQU $3400
; SECTORIZED BUFFER
; POINTER IS BUF3LOC
;
BUFF4 EQU $3500
; TRACK READ/WRITE BUFFER
; POINTER IS BUF4LOC
; RUNS FROM $3500->$5500
;
;
;
; START
;
START JSR HOME
 JSR SETUP
 JMP COMMNDIN
DRVON LDA $C08C,X; Q6 OFF
 LDA $C08E,X; Q7 OFF
 LDA $C08B,X; DRV 2
 LDA $C089,X; ON
 RTS
MARM  LDA DTRK
 ASL;MULT *2
 STA DTRK
MARM1 LDY TRK
 CPY DTRK
 BEQ MARM3
 BPL MARM2
 INC TRK
 INC TRK
MARM2 DEC TRK
 LDA TRK
 AND #$03
 ASL
 ORA SLOT
 TAX
 LDA $C081,X
 LDA #$56
 JSR DELAY
 LDA $C080,X
 JMP MARM1
MARM3 LDX SLOT
 STY TRK
 RTS
;  WRITEPROTECTED  
WRITPRO JMP MONITOR
;  WRITE  
WRITE JSR FINDSEC
WRA LDA $C08C,X
 BPL WRA
 STA $340
;
;
INIT9 SEC
 LDX SLOT
 STX SLOT1
; CHECK FOR WRITE PROTECT
 LDA $C08D,X
 LDA $C08E,X
 BMI WRITPRO
; GET FIRST BYTE 2NDARY BUFFER
 LDA BUFF2
 STA ST1
; DO FIRST WRITE
 LDA #$FF
 STA $C08F,X
 ORA $C08C,X
; WASTE TIME
 PHA
 PLA
 NOP
 LDY #$04
WR1 PHA;3
 PLA;4
 JSR WRTIME;6+22
 DEY;2
 BNE WR1;2
; WRITE FIRST BYTES
 LDA DP1
 JSR WRB1
 LDA DP2
 JSR WRB1
 LDA DP3
 JSR WRB1
; WRITE 2NDAY BUFFER
 TYA
 LDY #$56
 BNE WR2
WR3 LDA BUFF2,Y;5
WR2 EOR BUFF2-1,Y;4
 TAX;2
 LDA WBUFFD,X;5
 LDX SLOT1;2
 STA $C08D,X;5
 LDA $C08C,X;5
 DEY;2
 BNE WR3;2
 LDA ST1
 NOP
; WRITE 1ST BUFFER
WR4 EOR BUFF1,Y
 TAX
 LDA WBUFFD,X
 LDX SLOT
 STA $C08D,X
 LDA $C08C,X
 LDA BUFF1,Y
 INY
 BNE WR4
; CHECKSUM
 TAX
 LDA WBUFFD,X
 LDX SLOT1
 JSR WRITBT2
; WRITE ENDING BYTES
 LDA DE1
 JSR WRB1
 LDA DE2
 JSR WRB1
 LDA DE3
 JSR WRB1
 LDA #$FF
 JSR WRITBT
; PUT IN READ MODE
 LDA $C08E,X
 LDA $C08C,X
 RTS
WRITBT CLC
WRB1   NOP;2
 NOP;2
 NOP;2
 NOP;2
 STA $C08D,X;5
 LDA $C08C,X;5
 RTS
WRTIME PHA;3
 PLA;4
WRITBT2 STA $C08D,X;5
 ORA $C08C,X;4
 RTS;6
FINDSEC NOP
; PUT IN READ MODE
 LDA $C08E,X
 LDA $C08C,X
; FIND #$D5 (ADDRESS)
R1   LDA $C08C,X
 BPL R1
R1.1 STA BSTR
 EOR #$D5
 BNE R1
; FIND #$AA (ADDRESS)
R2 LDA $C08C,X
 BPL R2
 STA BSTR+1
 EOR #$AA
 BNE R1
;FIND #$96 (ADDRESS)
R3 LDA $C08C,X
 BPL R3
 STA BSTR+2
 EOR #$96
 BNE R1
;SKIP VOLUME BYTE ONE
R4 LDA $C08C,X
 BPL R4
 STA BSTR+3
;SKIP VOLUME BYTE TWO
R4.1 LDA $C08C,X
 BPL R4.1
 STA BSTR+4
;SKIP TRACK BYTE ONE
R4.2 LDA $C08C,X
 BPL R4.2
 STA BSTR+5
;SKIP TRACK BYTE TWO
R4.3 LDA $C08C,X
 BPL R4.3
 STA BSTR+6
; CHECK OUT SECTOR BYTE ONE
R8 LDA $C08C,X
 BPL R8
 CMP SECB1
 BNE R1
; CHECK OUT SECTOR BYTE TWO
R8.1 LDA $C08C,X
 BPL R8.1
 CMP SECB2
BRANCH BNE R1
; SKIP CHECKSUM BYTE ONE
R9 LDA $C08C,X
 BPL R9
 STA BSTR+7
; SKIP CHECKSUM BYTE TWO
R9.1 LDA $C08C,X
 BPL R9.1
 STA BSTR+8
; SKIP EPILOGUE BYTES (3)
R10 LDA $C08C,X
 BPL R10
 STA BSTR+9
R10.1 LDA $C08C,X
 BPL R10.1
 STA BSTR+10
 RTS
R10.2 LDA $C08C,X
 BPL R10.2
 STA BSTR+11
 RTS
READ NOP
 JSR FINDSEC
; LOOK FOR DATA'S #$D5
R5 LDA $C08C,X
 BPL R5
 EOR #$D5
 BNE R5
; LOOK FOR DATA'S #$AA
R6 LDA $C08C,X
 BPL R6
 EOR #$AA
 BNE BRANCH
; LOOK FOR DATA'S #$AD
 LDY #$56
R7 LDA $C08C,X
 BPL R7
 CMP #$AD
 BNE BRANCH
; LOAD SECONDARY BUFFER
 LDA #$00
RN1 DEY
RN1.2 STY RDSC1
RN1.1 LDY $C08C,X
 BPL RN1.1
 EOR RBUFFD,Y
 LDY RDSC1
 STA BUFF2 ,Y
 BNE RN1
; FILL PRIMARY BUFFER
RN2 STY RDSC1
RN2.1 LDY $C08C,X
 BPL RN2.1
 EOR RBUFFD,Y
 LDY RDSC1
 STA BUFF1,Y
 INY
 BNE RN2
;STORE VALUE OF ACC
 STA BSTR+16
; GET DISK CHECKSUM BYTE
RN3 LDY $C08C,X
 BPL RN3
 STY BSTR+14
; TURN OFF DRIVE
 LDA $C088,X
; GET CALCULATED CHECKSUM BYTE
 LDY BSTR+14
 LDA RBUFFD,Y
 STA BSTR+15
; CHECK IF SAME
 LDA BSTR+16
 CMP BSTR+15
 BNE EXITERR
EXITCL LDA #$80
 STA BSTR+17
 JMP EXITRD
EXITERR LDA #$FF
 STA BSTR+17
 JMP MONITOR
; EXIT READ
EXITRD LDX SLOT
 RTS
POSTNIB NOP
 LDA #$00
 STA ST1
 LDA BUF3LOC
 STA ST2
 LDY #$00
POSTNIB1 LDX #$56
POSTNIB2 DEX
 BMI POSTNIB1
 LDA BUFF1,Y
 LSR BUFF2,X
 ROL
 LSR BUFF2,X
 ROL
 STA (ST1),Y
 INY
 CPY #$00
 BNE POSTNIB2
 LDX SLOT
 RTS
PRENIB NOP
 LDA #$00
 STA ST1
 LDA BUF3LOC
 STA ST2
 LDX #$00
 LDY #$02
PRENIB1 DEY
 LDA (ST1),Y
 LSR
 ROL BUFF2 ,X
 LSR
 ROL BUFF2,X
 STA BUFF1,Y
 INX
 CPX #$56
 BCC PRENIB1
 LDX #$00
 TYA
 BNE PRENIB1
 LDX #$55
PRENIB2 LDA BUFF2,X
 AND #$3F
 STA  BUFF2,X
 DEX
 BPL PRENIB2
 LDX SLOT
 RTS
;
; READ A TRACK
;
RDTRK NOP
; SETUP
 JSR TRKRW
; READ MODE
 LDA $C08E,X
 LDA $C08C,X
; FIND SOME #$FF'S
; SO THAT IN SYNC
RDTRK2 LDY #$05
RDTRK3 LDA $C08C,X
 BPL RDTRK3
 CMP #$FF
 BNE RDTRK2
 DEY
 BNE RDTRK3
; READ INFORMATION
RDTRK1 LDA $C08C,X
 BPL RDTRK1
 STA (ST1),Y
; INC POINTERS
 INY
 BNE RDTRK1
; NEXT PAGE
 INC ST2
 LDA ST2
 CMP ST3
 BNE RDTRK1
; EXIT
 LDA $C088,X
 RTS
;
; INITIALIZE A TRACK
;
; WRITE PROTECTED
INIT8 JMP MONITOR
INIT1 RTS
INIT NOP
; DO SETUP
;  
; VOL = 256
 LDA #$FF
 STA VOL
; $3E = #$AA
 LDA #$AA
 STA $3E
;  
; PUT VOL IN ZERO PAGE
 LDA VOL
 STA ST3
; PUT UTRK IN ZERO PAGE
 LDA UTRK
 STA ST4
;  
; GET TRACK
 JSR INFOIN2
; BLANK BUFF1 + BUFF2
 JSR BNKBF1
 JSR BNKBF2
; TURN ON DRIVE
 LDX SLOT
 JSR DRVON
; GOTO TRACK
 LDA UTRK
 STA DTRK
 JSR MARM
; START SECTOR $0F
 LDA #$10
 STA ST2
; START WITH 256 SYNCS
 LDY #$FF
INIT5 DEC ST2
 JSR INITER
; WRITE DATA
 LDX SLOT
 STX SLOT1
 JSR INIT9
; DO 16 SYNCS NEXT TRACKS
 LDY #$0F
; CONTINUE TRACK LOOP
 LDA ST2
 CMP #$00
 BNE INIT5
 JMP INIT6
INITER NOP
; CHECK FOR WRITE PROTECT
 LDA $C08D,X
 LDA $C08E,X
 BMI INIT8
; DO FIRST WRITE
; THIS PUTS IN WRITE MODE
 SEC
 LDA #$FF
 LDX SLOT
 STA $C08F,X
 CMP $C08C,X
; WASTE TIME
 PHA
 PLA
; WRITE AUTOSYNCS
INIT2 PHA;3
 PLA;4
 JSR INIT10;6+22
 DEY;2
 BNE INIT2;2
; WRITE SECTOR HEADER
 LDA AP1
 JSR INIT11
 LDA AP2
 JSR INIT11
 LDA AP3
 JSR INIT11
; DISK VOL 256
 LDA ST3
 JSR INIT4
 LDA ST4
 JSR INIT4
 LDA ST2
 JSR INIT4
 LDA ST3
 EOR ST4
 EOR ST1
 PHA
 LSR
 ORA $3E
 STA $C08D,X
 LDA $C08C,X
 PLA
 ORA #$AA
 JSR INIT7
 LDA AE1
 JSR INIT11
 LDA AE2
 JSR INIT11
 LDA AE3
 JSR INIT11
 RTS
; EXIT
INIT6 NOP
; PUT IN READ MODE
 LDA $C08E,X
 LDA $C08C,X
; TURN OFF DRIVE
 LDA $C088,X
 RTS
INIT4 PHA
 LSR
 ORA $3E;ORA #$AA
 STA $C08D,X
 CMP $C08C,X
 PLA
 NOP
 NOP
 NOP
 ORA #$AA
INIT7 NOP;2
INIT3 NOP;2
INIT10 PHA;3
 PLA;4
 STA $C08D,X;5
 CMP $C08C,X;4
 RTS;6
INIT11 NOP;2
 NOP;2
 NOP;2
 NOP;2
 STA $C08D,X;5
 LDA $C08C,X;5
 RTS
;
; BLANK BUFF1
;
BNKBF1   NOP
 LDA BUF1LOC
 STA ST2
 LDA #$00
 STA ST1
 LDY #$00
BNKBF1.2 STA (ST1),Y
 INY
 BNE BNKBF1.2
 RTS
;
; BLANK BUFF2
;
BNKBF2 NOP
 LDA BUF2LOC
 STA ST2
 LDA #$00
 STA ST1
 LDY #$00
BNKBF2.2 STA (ST1),Y
 INY
 BNE BNKBF2.2
 RTS
; CODE COMMON TO TRACK READ
; AND TRACK WRITE
TRKRW NOP
; GET TRACK
 JSR INFOIN2
; TURN ON DRIVE
 LDX SLOT
 JSR DRVON
; GOTO TRACK
 LDA UTRK
 STA DTRK
 JSR MARM
; CALC ENDING PAGE
; NOBYTS = PAGES NEEDED
 LDA BUF4LOC
 CLC
 ADC NOBYTS
 STA ST3
; SETUP POINTERS
 LDA #$00
 STA ST1
 LDA BUF4LOC
 STA ST2
 LDY #$00
 RTS
SETUP LDX #$60
 STX SLOT
; SETUP SECTOR BYTES
 LDA #$D5
 STA AP1
 LDA #$AA
 STA AP2
 LDA #$96
 STA AP3
 LDA #$DE
 STA AE1
 LDA #$AA
 STA AE2
 LDA #$EB
 STA AE3
 LDA #$D5
 STA DP1
 LDA #$AA
 STA DP2
 LDA #$AD
 STA DP3
 LDA #$DE
 STA DE1
 LDA #$AA
 STA DE2
 LDA #$EB
 STA DE3
; SETUP NUMBER OF PAGES
; FOR TRACK READ/WRITE
 LDA #$20
 STA NOBYTS
; SET BUFFER LOCATIONS
 LDA #$30
 STA WRTRLOC
 LDA #$31
 STA RDTRLOC
 LDA #$32
 STA BUF1LOC
 LDA #$33
 STA BUF2LOC
 LDA #$34
 STA BUF3LOC
 LDA #$35
 STA BUF4LOC
; SET RESET VECTOR TO START
;LDA #START
;STA $3F2
;LDA #START/
;STA $3F3
;JSR $FB6F
; SETUP READ TRANSLATE TABLE
 LDA #$00
 STA ST1
 LDA RDTRLOC
 STA ST2
 LDY #$96
 LDX #$00
SET1 LDA RDTRANS,X
 STA (ST1),Y
 INX
 INY
 BNE SET1
; SETUP WRITE TRANSLATE TABLE
 LDA #$00
 STA ST1
 LDA WRTRLOC
 STA ST2
 LDY #$29
 LDX #$00
SET2 LDA WRTRANS,X
 STA (ST1),Y
 INX
 INY
 CPY #$69
 BNE SET2
; RECALIBRATE THE DRIVE
 LDX SLOT
 LDA #$00
 STA DTRK
 LDA #$50
 STA TRK
 JSR DRVON
 JSR MARM1
 LDA $C088,X
 RTS
GTSECN NOP
 LDA DSEC
 ASL;MULT *2
 TAY
 INY
 LDA SECDAT,Y
 STA SECB1
 INY
 LDA SECDAT,Y
 STA SECB2
 RTS
;CTPHY TURNS THE LOGICAL SECTOR
;NUMBER IN DSEC TO PHYSICAL
CTPHY NOP
 LDY USEC
 INY
 LDA SECEQU,Y
 STA DSEC
 RTS
;READ TRANSLATE TABLE
;FOUND AT $BA96-> $BAFF IN DOS 3.3
RDTRANS DFC $00,$01,$98
 DFC $99,$02,$03,$9C,$04,$05,$06
 DFC $A0,$A1,$A2,$A3,$A4,$A5
 DFC $07,$08,$A8
 DFC $A9,$AA,$09,$0A,$0B,$0C,$0D
 DFC $B0,$B1,$0E,$0F,$10,$11,$12
 DFC $13,$B8,$14,$15,$16,$17,$18
 DFC $19,$1A,$C0,$C1,$C2,$C3,$C4
 DFC $C5,$C6,$C7,$C8,$C9,$CA,$1B
 DFC $CC,$1C,$1D,$1E,$D0,$D1,$D2
 DFC $1F,$D4,$D5,$20,$21,$D8,$22
 DFC $23,$24,$25,$26,$27,$28,$E0
 DFC $E1,$E2,$E3,$E4,$29,$2A,$2B
 DFC $E8,$2C,$2D,$2E,$2F,$30,$31
 DFC $32,$F0,$F1,$33,$34,$35,$36
 DFC $37,$38,$F8,$39,$3A,$3B,$3C
 DFC $3D,$3E,$3F
; WRITE TRANSLATE TABLE
; FOUND AT $BA29 -> $BA68 IN DOS
WRTRANS DFC $96,$97
 DFC $9A, $9B
 DFC $9D, $9E,$9F
 DFC $A6,$A7
 DFC $AB, $AC,$AD,$AE
 DFC $AF,$B2,$B3
 DFC $B4,$B5
 DFC $B6,$B7
 DFC $B9,$BA,$BB
 DFC $BC,$BD,$BE
 DFC $BF,$CB
 DFC $CD,$CE,$CF
 DFC $D3,$D6,$D7
 DFC $D9,$DA,$DB
 DFC $DC,$DD,$DE,$DF
 DFC $E5,$E6,$E7
 DFC $E9,$EA,$EB,$EC
 DFC $ED,$EE,$EF
 DFC $F2,$F3,$F4,$F5,$F6,$F7
 DFC $F9,$FA,$FB,$FC,$FD,$FE,$FF
;DATA TABLE OF LOGICAL SECTOR #'S
SECEQU NOP
 DFC $00,$0D,$0B,$09,$07,$05,$03,$01,$0E,$0C,$0A,$08,$06,$04,$02,$0F
;DATA TABLE OF SECTOR NUMBER BYTES
SECDAT NOP
D0 DFC $AA,$AA
D1 DFC $AA,$AB
D2 DFC $AB,$AA
D3 DFC $AB,$AB
D4 DFC $AA,$AE
D5 DFC $AA,$AF
D6 DFC $AB,$AE
D7 DFC $AB,$AF
D8 DFC $AE,$AA
D9 DFC $AE,$AB
DA DFC $AF,$AA
DB DFC $AF,$AB
DC DFC $AE,$AE
DD DFC $AE,$AF
DE DFC $AF,$AE
DF DFC $AF,$AF
WORDS1 ASC "TRACK "
WORDS2 ASC "SECTOR "
WORDS3 ASC "COMMAND "
HEXIN JSR KEYIN
 CMP #$9B
 BEQ EXIT
 CMP #$88
 BEQ HEXIN
 JSR CONV
 STA ST1
 JSR DIGOUT
 LDA ST1
 ASL
 ASL
 ASL
 ASL
 STA ST1
HEXIN1 JSR KEYIN
 CMP #$9B
 BEQ EXIT
 CMP #$88
 BEQ HEXIN1
 JSR CONV
 STA ST2
 JSR DIGOUT
 LDA ST2
 ORA ST1
 STA ST1
 RTS
CONV CMP #$C0
 BPL C1
 SBC #$AF
 JMP C2
C1 SBC #$B7
C2 RTS
EXIT JMP $3D0
INFOIN2 NOP
 LDX #$00
 LDY #$15
 JSR TAB
 JMP PR3
INFOIN NOP
 LDX #$00
 LDY #$14
 JSR TAB
 LDY #$00
PR2 LDA WORDS2,Y
 JSR COUT
 INY
 CPY #$07
 BNE PR2
 JSR HEXIN
 STA USEC
 JSR CROUT
PR3 LDY #$00
PR1 LDA WORDS1,Y
 JSR COUT
 INY
 CPY #$06
 BNE PR1
 JSR HEXIN
 STA UTRK
 RTS
;
; SCREEN EDITOR FOR DISK PROGRAM
; STARTED FEB 20, 1989
; BY THOMAS EVERETT
;PT1 POINTS TO POSITION IN BUFFER
;TOPBUF AND BOTBUF POINT TO
;START AND END OF BUFFER
;
; START
;
COMMNDIN JSR SHOW256
COMMND JSR SHOWPOS
 LDX CX
 LDY CY
 JSR TAB
 JSR KEYIN
 JSR BEEP
; INTERPERT INPUT
COMMND1 NOP
 CMP #$C9
 BEQ CUPJ
 CMP #$8B
 BEQ CUPJ
 CMP #$CD
 BEQ CDOWNJ
 CMP #$8A
 BEQ CDOWNJ
 CMP #$88
 BEQ CLEFJ
 CMP #$95
 BEQ CRJ
 CMP #$8D
 BEQ RETJ
 CMP #$9B
 BEQ ESCJ
 CMP #$D2
 BEQ READCOMJ
 CMP #$D7
 BEQ WRITCOMJ
 CMP #$B1
 BEQ SHOW256J
 CMP #$B2
 BEQ SHOWPRMJ
 CMP #$B3
 BEQ SHOW2NDJ
 CMP #$B4
 BEQ SHOW4J
 CMP #$CE
 BEQ PRENJ
 CMP #$C4
 BEQ POSTNJ
 CMP #$DA
 BEQ RDTRKJ
 CMP #$D8
 BEQ INITJ
 CMP #$AC;,
 BEQ CONSTDNJ
 CMP #$AE
 BEQ CONSTUPJ;.
 CMP #$CC
 BEQ LISTJ
 JMP COMMND
;JUMP TABLE
CUPJ JSR CUP
 JMP COMMND
CDOWNJ JSR CDOWN
 JMP COMMND
CLEFJ JMP CLEF
CRJ JMP CR
RETJ JMP RET
ESCJ JMP ESC
READCOMJ JMP READCOM
WRITCOMJ JMP WRITCOM
SHOW256J JSR SHOW256
 JMP COMMND
SHOWPRMJ  JSR SHOWPRM
 JMP COMMND
SHOW2NDJ JSR SHOW2ND
 JMP COMMND
SHOW4J JSR SHOW4
 JMP COMMND
PRENJ JSR PRENIB
 JMP COMMND
POSTNJ JSR POSTNIB
 JMP COMMND
RDTRKJ JSR RDTRK
 JMP COMMND
INITJ JSR INIT
 JMP COMMND
CONSTDNJ JSR CONSTDN
 JMP COMMND
CONSTUPJ JSR CONSTUP
 JMP COMMND
LISTJ JSR LIST
 JMP COMMND
CUP NOP
; AT TOP OF BUFFER?
 LDA PT1H
 CMP TOPBUFH
 BNE CUP1
 LDA PT1L
 CMP TOPBUFL
 BNE CUP1
; YES
; CURSOR AT TOP OF SCREEN?
 LDY CY
 CPY #$02
 BNE CUP2
; YES
; DO NOTHING
 RTS
; MOVE UP CURSR
CUP2 LDY CY
 DEY
 STY CY
 LDA POS
 SEC
 SBC #$08
 STA POS
 RTS
CUP1 NOP
; CURSOR AT BOTTOM OF BUFFER?
 LDY #$05
 CPY CY
 BCC CUP2
; MOVE UP PAGE
 JSR UP
 RTS
CDOWN NOP
; AT BOTTOM OF BUFFER?
 LDA PT1H
 CMP BOTBUFH
 BNE CDOWN1
 LDA PT1L
 CMP BOTBUFL
 BNE CDOWN1
; YES
; CURSOR AT BOTTOM OF SCREEN?
 LDY CY
 CPY #$08
 BNE CDOWN2
; YES
; DO NOTHING
 RTS
; MOVE DOWN CURSOR
CDOWN2 LDY CY
 INY
 STY CY
 LDA POS
 CLC
 ADC #$08
 STA POS
 RTS
CDOWN1 NOP
; AT TOP OF SCREEN
 LDY CY
 CPY #$05
 BCC CDOWN2
; NO
; MOVE PAGE DOWN
 JSR DOWN
 RTS
CLEF NOP
; GET X POSITION
 LDA CX
; AT LEFT EGDE?
 BEQ CLEF1
; NO SUBTRACT #$04 FROM X
 SEC
 SBC #$03
 STA CX
; DEC POS
 DEC POS
CLEF1 JMP COMMND
CR NOP
; GET X POSITION
 LDA CX
; AT RIGHT EDGE?
 CMP #$15
; YES, EXIT
 BEQ CR1
; NO ADD #$04 TO X
 CLC
 ADC #$03
 STA CX
; INC POS
 INC POS
CR1 JMP COMMND
RET LDX #$0D
 LDY #$14
 JSR TAB
 JSR HEXIN
 LDY POS
 STA (PT1L),Y
 JSR PRNT
 JMP COMMND
ESC JMP MONITOR
READCOM JSR INFOIN
 LDX SLOT
 JSR DRVON;DRV ON
 LDA UTRK
 STA DTRK
 JSR MARM;DO ARM
 JSR CTPHY;L TO P
 JSR GTSECN; BYTES
 JSR READ
 JSR POSTNIB
 LDX SLOT
 LDA $C088,X
 JSR SHOW256
 JMP COMMND
WRITCOM JSR INFOIN
 LDX SLOT
 JSR DRVON
 LDA UTRK
 STA DTRK
 JSR MARM
 JSR CTPHY
 JSR GTSECN
 JSR PRENIB
 JSR WRITE
 LDA $C088,X
 JMP COMMND
CONSTDN NOP
CONST1 LDA KEYBD
 BPL CONST2
 BIT STROBE
 RTS
CONST2 JSR CDOWN
 JSR SHOWPOS
 JMP CONST1
CONSTUP NOP
CONST3 LDA KEYBD
 BPL CONST4
 BIT STROBE
 RTS
CONST4 JSR CUP
 JSR SHOWPOS
 JMP CONST3
LIST NOP
 LDA $3B
 STA ST2
 LDA $3A
 STA ST1
; POSITION ON SCREEN
 LDX #$00
 LDY #$09
 JSR TAB
; CALCULATE PRESENT POSITION
 LDA PT1L
 CLC
 ADC POS
 BCS LIST2
 TAX
 LDA PT1H
LIST3 STA $3B
 STX $3A
 JSR LISTER
 LDA ST2
 STA $3B
 LDA ST1
 STA $3A
 RTS
LIST2 TAX
 LDY PT1H
 INY
 TYA
 JMP LIST3
LISTER TSX
 STX ST1
 JSR $FE75
 LDA #$05
LISTER2 PHA
 JSR $F8D0
 JSR $F953
 STA $3A
 STY $3B
 PLA
 SEC
 SBC #$01
 BNE LISTER2
 LDX ST1
 TXS
 RTS
SHOW256 LDX BUF3LOC
 JMP SETPNTS
SHOWPRM  LDX BUF1LOC
 JMP SETPNTS
SHOW2ND LDX BUF2LOC
 JMP SETPNTS
SHOW4 LDA BUF4LOC
 STA PT1H
 STA TOPBUFH
 CLC
 ADC NOBYTS
 STA BOTBUFH
 LDA #$00
 STA BOTBUFL
 STA TOPBUFL
 JMP SETPNTS1
SETPNTS NOP
; SET POINTER HIGH
 STX PT1H
; SET BUFFER BOUNDRIES
 STX TOPBUFH
 INX
 STX BOTBUFH
 LDX #$00
 STX TOPBUFL
 STX BOTBUFL
; CURSOR POSITON
SETPNTS1 LDX #$18
 STX POS
; CURSOR X POSITION
 LDA #$00
 STA CX
; CURSOR Y POSITION
 LDA #$05
 STA CY
; POINTER LOW
 LDA #$00
 STA PT1L
 RTS
; MOVE PAGE UP
UP  LDA PT1L
 BEQ UP1
 SEC
 SBC #$08
 STA PT1L
 RTS
UP1 SEC
 SBC #$08
 STA PT1L
 DEC PT1H
 RTS
; MOVE PAGE DOWN
DOWN LDA PT1L
 CMP #$F8
 BEQ DOWN1
 CLC
 ADC #$08
 STA PT1L
 RTS
DOWN1 CLC
 ADC #$08
 STA PT1L
 INC PT1H
 RTS
SETINV PHA
 TYA
 PHA
 JSR INVERSE
 PLA
 TAY
 PLA
 RTS
SETNORM PHA
 TYA
 PHA
 JSR NORMAL
 PLA
 TAY
 PLA
 RTS
TAB  NOP
 STX $24
 STY $25
 JSR VTAB
 RTS
BEEP  LDY #$50
BEEP2 BIT SPKR
 DEY
 BNE BEEP2
 RTS
SHOWPOS LDX #$00
 LDY #$13
 JSR TAB
 LDA PT1H
 LDX PT1L
 JSR PRTAX
 LDX #$01
 JSR PRBL2
 LDA POS
 JSR PRHEX
 LDX #$01
 JSR PRBL2
; DISPLAY ACTUAL POSITION IN BUFF
 LDA PT1L
 CLC
 ADC POS
 BCS SHOWPOS2
 TAX
 LDA PT1H
SHOWPOS3 JSR PRTAX
 JSR PRNT
 RTS
SHOWPOS2 TAX
 LDY PT1H
 INY
 TYA
 JMP SHOWPOS3
PRNT NOP
 LDA #$01
 STA ST2
 LDY #$00
 JMP PRNT4
PRNT1 LDX #$08
PRNT2 NOP
 LDA (PT1L),Y
 STA ST4
 JSR SAVEREG
 JSR PRNUM
 JSR PRCHR
 JSR GETREG
; DONE #$38 CHARS?
 INY
 CPY #$38
 BEQ PRNT3
 DEX
 BNE PRNT2
; DONE #$08 ACROSS, RESET REGS
PRNT4 LDA #$00
 STA ST1
 LDA #$19
 STA ST3
 INC ST2
 JMP PRNT1
PRNT3 RTS
PRNUM NOP
; POSITION ON SCREEN
 LDX ST1
 LDY ST2
 JSR TAB
; HIGHLIGHT #$FF
 LDA ST4
 CMP #$FF
 BNE PRNUM1
 JSR SETINV
PRNUM1 JSR PRHEX
 JSR SETNORM
 INC ST1
 INC ST1
 INC ST1
 RTS
PRCHR NOP
; POSITION ON SCREEN
 LDX ST3
 LDY ST2
 JSR TAB
; GET CHAR
 LDA ST4
; PRINT
 JSR COUT
 INC ST3
 RTS