10 CLEAR1000
20 EXEC &H6C00
30 ALL
40 *RDISK V1.0 - (C)1992 BY J.BIRD
50 *RAM DISK FOR DDOS
60 *EQUATES
70 ORG 490
80 @DDR EQU 56
90 @OFF EQU 60
100 @ACT EQU 44
110 @EXTMSR EQU 1
120 @READ EQU 2
130 @WRIT EQU 6
140 @EXTLSR EQU 8
150 @OUT EQU 255
160 @OUTB EQU 15
170 @IOA EQU $FF34
180 @CRA EQU $FF35
190 @IOB EQU $FF36
200 @CRB EQU $FF37
210 @LSN RMB 2
220 *INIT - COPY ROM TO RAM
230 @INIT ORCC #$50
240 LDX #32768
250 @CRAM LDA ,X
260 STA $FFDF
270 STA ,X+
280 STA $FFDE
290 CMPX #57344
300 BLO @CRAM
302 LDX #@RESET
304 STX 157
306 STA $FFDF
310 RTS
320 @RESET STA $FFDF
330 *SETUP B SIDE PIA FOR RDISK
340 LDA #@DDR
350 STA @CRB
360 LDA #@OUTB
370 STA @IOB
380 LDA #@OFF
390 STA @CRB
400 *PATCH DSKCOM ROUTINE
410 LDA #$7E
420 STA $C17C
430 LDX #@DSKCOM
440 STX $C17D
450 CLR @IOB
460 ANDCC #$AF
470 RTS
480 FML:FMS
490 ORG $E000
500 *DSKCOM - PATCH FOR DSKCOM
510 *CHECK FOR DRIVE 4
520 @DSKCOM LDA >$EB
530 CMPA #4
540 BEQ @RAMDISC
550 LDA $FF40
560 JMP $C17F
570 *RAMDISC-CALC LSN
580 @RAMDISC LDA >$EC
590 LDB #18
600 MUL
610 ADDB >$ED
620 BCC @GOTLSN
630 ADDA #1
640 @GOTLSN CMPD #1024
650 BHI @TRERR
660 STD @LSN
670 *BRANCH TO COMMANDS
680 LDA >$EA
690 BEQ @RESTORE
700 CMPA #1
710 BEQ @SEEK
720 CMPA #2
730 BEQ @READS
740 CMPA #3
750 LBEQ @WRITE
760 CMPA #4
770 LBEQ @WRITE
780 CMPA #5
790 BEQ @FORMAT
800 CMPA #6
810 BEQ @FORMAT
820 CMPA #7
830 BEQ @READS
840 CMPA #8
850 BEQ @FORMAT
860 LDB #8
870 ORCC #1
880 @EXIT STB >$F0
890 PULS U,Y,X,DP,A,CC
900 LDB >$F0
910 RTS
920 @FORMAT CLRB
930 BRA @EXIT
940 @TRERR LDB #135
950 ORCC #1
960 BRA @EXIT
970 *RESTORE - SET LSN TO 0000
980 @RESTORE CLR @LSN
990 CLR @LSN+1
1000 *SEEK - MOVE TO SECTOR IN RAM
1010 @SEEK LDA #@DDR
1020 STA @CRA
1030 LDA #@OUT
1040 STA @IOA
1050 LDA #@ACT
1060 STA @CRA
1070 LDA #@EXTMSR
1080 STA @IOB
1090 LDD @LSN
1100 STA @IOA
1110 LDA @IOA
1120 LDA #@EXTLSR
1130 STA @IOB
1140 STB @IOA
1150 LDB @IOA
1160 CLR @IOB
1170 LDA #@OFF
1180 STA @IOA
1190 CLRB
1200 BRA @EXIT
1210 *READ - READ SECTOR - INCLUDES VERIFY
1220 @READS LDA #@DDR
1230 STA @CRA
1240 CLR @IOA
1250 LDA #@ACT
1260 STA @CRA
1270 LDA #@READ
1280 STA @IOB
1290 LDX >$EE
1300 CLRB
1310 LDA >$EA
1320 CMPA #7
1330 BNE @RDLP
1340 *VERIFY-READ FIRST TWO BYTES INTO 79/80
1350 LDB #2
1360 LDX #79
1370 @RDLP LDA @IOA
1380 STA ,X+
1390 DECB
1400 BNE @RDLP
1410 CLR @IOB
1420 LDA #@OFF
1430 STA @IOA
1440 CLRB
1450 BRA @EXIT
1460 *WRITE-WRITE SECTOR
1470 @WRITE LDA #@DDR
1480 STA @CRA
1490 LDA #@OUT
1500 STA @IOA
1510 LDA #@ACT
1520 STA @CRA
1530 LDA #@WRIT
1540 STA @IOB
1550 LDX >$EE
1560 CLRB
1570 @WRTLP LDA ,X+
1580 STA @IOA
1590 LDA @IOA
1600 DECB
1610 BNE @WRTLP
1620 CLR @IOB
1630 LDA #@OFF
1640 STA @CRA
1650 LBRA @FORMAT
1660 FML
1670 END @INIT