Subversion Repositories System09

*
** FLEX 9 DISK DRIVERS
*
* FOR SYS09BUG ON THE DIGILENT SPARTAN 3 STARTER BOARD
* WITH I/O MAPPED AT $XE000
* AND ROM MAPPED AT $XF000
* THE DIGILENT SPARTAN 3 STARTER BOARD HAS 1MBYTE OF SRAM
* THE FIRST 64K IS USED BY FLEX,
* THE SECOND 128K IS USED AS A ROM DISK
* THE REMAINING RAM IS USED FOR A RAM DISK
*
*
CFLAG   EQU $01     CARRY FLAG
VFLAG   EQU $02     OVERFLOW FLAG
ZFLAG   EQU $04     ZERO FLAG
NFLAG   EQU $08     NEGATIVE FLAG
IFLAG   EQU $10     IRQ MASK CC
HFLAG   EQU $20     HALF CARRY
FFLAG   EQU $40     FIRQ MASK CC
EFLAG   EQU $80     ENTIRE FLAG
*
MAPPAG  EQU $00     PAGE $0000 DAT ADDRESS
*
* Serial Port
*
ACIAS   EQU $E000
ACIAC1  EQU ACIAS
ACIAD1  EQU ACIAS+1
DELCON  EQU 1250    Delay (Processor clock in MHz * 50)
*
* XMODEM Control characters
*
SOH     EQU $01
EOT     EQU $04
ACK     EQU $06
NAK     EQU $15
CAN     EQU $18
*
* ASCII CONTROL CHARACTERS
*
HT      EQU $09
LF      EQU $0A
CR      EQU $0D
*
* Some dummy Constants
*
RMAXTRK EQU 48
RMAXSEC EQU 14
RTOTSEC EQU RMAXTRK*RMAXSEC-RMAXSEC
*
* Start
*
        ORG $0100
START   LBRA  LOAD1
*
*
* RAM SPACE
*
CHKSUM  FCB  0
BLKNUM  FCB  0 Xmodem block number
BYTCNT  FCB  0 Xmodem byte count
XSTATE  FDB  0 Xmodem State Vector
DELCNT  FCB  $00,$00,$00 Xmodem Poll timer
BUFPTR  FDB 0
TEXTFL  FCB 0
LINECT  FCB 0
        ORG  $0200
*
* SECTOR BUFFER
*
BUFFER  RMB  256
*
*
* ACIA INPUT TEST
*
INTEST  LDA ACIAC1
        BITA #$01
        RTS
*
* RESET ACIA
*
ACIRST  LDA #$03 master reset
        STA  ACIAC1
        LDA #$11
        STA ACIAC1
        RTS
*
* ACIA INPUT
*
INTER   LDA  #16
        STA  DELCNT+0
        CLR  DELCNT+1
        CLR  DELCNT+2
INTER0  LDA  ACIAC1
        BITA #$01
        BNE  INTER1
        BITA #$78
        BEQ  INTER2
        BSR  ACIRST
        BRA  INTER
*
INTER1  LDA  ACIAD1
        ANDCC #VFLAG
        RTS
*
INTER2  DEC  DELCNT+2
        BNE  INTER0
        DEC  DELCNT+1
        BNE  INTER0
        DEC  DELCNT+0
        BNE  INTER0
        CLRA
        ORCC #VFLAG
        RTS
*
* ACIA OUTPUT
*
OUTTER  PSHS A
*
OUTTE1  LDA ACIAC1
        BITA #$02
        BNE  OUTTE2
        BITA #$78
        BEQ  OUTTE1
        BSR  ACIRST
        BRA  OUTTE1
*
OUTTE2  PULS A
        STA ACIAD1
        RTS
*
* Print Data
*
PDATA0  BSR  OUTTER
PDATA1  LDA  ,X+
        CMPA #$04
        BNE  PDATA0
        RTS 
*
* Get a Byte using XModem protocol
* Carry clear => no errors
* Carry set   => errors
*
XREAD   PSHS U
        LDU  XSTATE
*
XBYTE0  LBSR INTER
        BVC  XBYTE1
        LDA  #NAK
        LBSR OUTTER
        LDU  #XSTS
        BRA  XBYTE0
*
XBYTE1  JSR  ,U
        BNE  XBYTE0
        STU  XSTATE
        PULS U,PC
*
* START - LOOK FOR SOH (START OF HEADER) = $01
*
XSTS  CMPA #SOH
        BNE  XSTS1
        LDU  #XSTB
        ANDCC #$FF-CFLAG-ZFLAG No abort, no valid data (no exit)
        RTS
*
XSTS1 CMPA #EOT
        BNE  XSTS2
        LDA  #ACK
        LBSR OUTTER
        ORCC  #CFLAG+ZFLAG  Set (c)=1 abort & exit
        RTS
*
XSTS2 CMPA #CAN
        BNE  XSTS3
        ORCC  #CFLAG+ZFLAG  Set (c)=1 abort & exit
        RTS
*
XSTS3 ANDCC #$FF-CFLAG-ZFLAG
        RTS
*
* Got SOH
* Now get block number
*
XSTB  CMPA BLKNUM
        BNE  XSTBE
        LDU  #XSTCOM
        ANDCC #$FF-CFLAG-ZFLAG No abort, No valid data (no exit)
        RTS
*
* Error in block number
*
XSTBE LDA  #NAK
        LBSR OUTTER
        LDU  #XSTS
        ANDCC #$FF-CFLAG-ZFLAG No abort, No valid data (no exit)
        RTS
*
* Get complement of block number
*
XSTCOM  COMA
        CMPA BLKNUM
        BNE  XSTBE
        CLR  CHKSUM
        LDA  #128
        STA  BYTCNT
        LDU  #XSTD
        ANDCC #$FF-CFLAG-ZFLAG No abort, No valid data (no exit)
        RTS
*
* Get data bytes
*
XSTD  PSHS A
        ADDA CHKSUM
        STA  CHKSUM
        PULS A
        DEC  BYTCNT
        BNE  XSTD1
        LDU  #XSTC
XSTD1 STA  ,X+
        ANDCC #$FF-CFLAG-ZFLAG No abort, no valid data (no exit)
        RTS
*
* Byte count reached zero
* Check checksum byte
*
XSTC  CMPA CHKSUM
        BNE  XSTC1 retry if wrong checksum
*
* Checksum OK ... 
* increment block number
* Don't send ACK until data written to CF
*
        INC  BLKNUM
        LDU  #XSTS
        ANDCC #$FF-CFLAG No abort
        ORCC #ZFLAG      Valid data (exit)
        RTS
*
* Checksum Error detected ...
* Reset Sector counter in ACCB to last 128 byte boundary
* and send NAK
*
XSTC1  LDX #BUFFER
        LDA  #NAK
XSTC2 LBSR OUTTER
        LDU  #XSTS
        ANDCC #$FF-CFLAG-ZFLAG No abort, no valid data (no exit)
        RTS
*
* Acknowledge Data Received
*
XACK    PSHS A
        LDA  #ACK
        LBSR OUTTER
        PULS A,PC
*
** FLEX CALLS
*
SYSFCB EQU $C840
WARMS  EQU $CD03
OUTCH  EQU $CD0F
OUTCH2 EQU $CD12
GETCHR EQU $CD15
PUTCHR EQU $CD18
PSTRNG EQU $CD1E
GETFIL EQU $CD2D
SETEXT EQU $CD33
RPTERR EQU $CD3F
GETHEX EQU $CD42
NXTCH  EQU $CD27
FMSCLS EQU $D403
FMS    EQU $D406
*
** MAIN ENTRY POINT
*
LOAD1  LDX #SYSFCB
       JSR >GETFIL
       BCC LOAD2
       LDB #$15
       STB $01,X
       JMP >FMSERR
LOAD2  JSR NXTCH
       ANDA #$5F
       CMPA #'T
       BNE LOAD3
       STA  TEXTFL
       LDX #TXTMSG
       JSR PDATA1
       BRA OPENWR
LOAD3  CMPA #$20
       BEQ LOAD2
*
** OPEN FILE FOR WRITE
*
OPENWR  LDX #SYSFCB
        LDA #$02
        STA ,X
        JSR >FMS
        LBNE DSKERR
        TST TEXTFL
        BEQ OPENW1
        LDA #$01
        JSR SETEXT
        BRA OPENW2
OPENW1  LDA #$FF
        STA $3B,X
OPENW2  EQU *
*
        LDU  #XSTS
        STU  XSTATE
        LDA  #1
        STA  BLKNUM
*
** WRITE BYTE TO DISK
*
WRLOOP LDX #BUFFER
       LBSR XREAD
       LBCS ABORT
       LDX #BUFFER
       LDB #128
       STX  BUFPTR
       STB  BYTCNT
WRLP1  LDX BUFPTR
       LDA ,X+
       STX BUFPTR
       TST  TEXTFL
       BEQ  WRLP2
       CMPA #HT
       BNE WRLP3
WRLP4  LDA  #$20
       LDX #SYSFCB
       JSR FMS
       INC LINECT
       LDA LINECT
       ANDA #$07
       BNE WRLP4
       BRA WRLP5
WRLP3  CMPA #LF
       BNE  WRLP2
       LDX  #SYSFCB
       JSR  FMS
       BNE DSKERR
       LDA  #CR
       CLR LINECT
       DEC LINECT
WRLP2  LDX #SYSFCB
       JSR >FMS
       BNE DSKERR
       INC LINECT
WRLP5  DEC  BYTCNT
       BNE  WRLP1
       LBSR XACK
       BRA  WRLOOP
*
** FINISHED LOAD
*
ABORT  LDX #ENDMSG
       JSR PSTRNG
       LBSR XACK
*
*
** CLOSE FILE
*
CLOSE  LDA #$04
       LDX #SYSFCB
       STA ,X
       JSR >FMS
       BEQ EXIT
*
** ERROR IN CLOSING
*
DSKERR LDA $01,X
FMSERR JSR >RPTERR
       JSR >FMSCLS
EXIT   JMP >WARMS
*
** MESSAGES
*
ENDMSG FCC "FILE LOADED"
       FCB $04
TXTMSG FCB $0D,$0A
       FCC "TEXT FILE"
       FCB $04
       END START