CP/M/CPM_CDROM.iso/cpm/mex/mxo-mw10.asm

Assembly Source File | 1994-07-13 | 14KB | 449 lines

    TITLE    'MEX RACAL-VADIC MAXWELL 1200V OVERLAY V1.0'
;
; (DELETE ABOVE TITLE LINE IF ASSEMBLING WITH ASM)
;
; MXO-MW10.ASM
;. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
; Revised from and thanks to:                    .
;                                .
; MXO-RV10.ASM  Original release 5/20/84            .
;                                .
; Racal Vadic VA212 overlay for MEX: revision 1.2        .
;  Written 20 May 1984 by Dave Mabry                .
;  Adapted using information and excerpts from Ron Fowler's    .
;   overlay for the PMMI modem.                     .
;. . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . .
;
;  MXO-MW10.ASM Released 9/25/84
; Racal-Vadic Maxwell 1200V overlay for mex revision 1.0
; questions or comments; leave message on Dark Chambers RiBBs
;            [phone]
;             Jim van der Heyden
;
; This overlay will work with any modem overlay that terminates
; prior to 0B00H
;
FALSE    EQU    0
TRUE    EQU    NOT FALSE
;
;
; SYSTEM CONSTANTS
;
DIALV    EQU    0162H        ;LOCATION OF DIAL VECTOR IN OVERLAY
DISCV    EQU    0165H        ;LOCATION OF DISCONNECT VECTOR IN OVERLAY
DIALOC    EQU    0B00H        ;DIALING CODE GOES HERE
;
;
; MEX service processor stuff ... MEX supports an overlay service
; processor, located at 0D00H (and maintained at this address from
; version to version).  If your overlay needs to call BDOS for any
; reason, it should call MEX instead; function calls below about
; 240 are simply passed on to the BDOS (console and list I/O calls
; are specially handled to allow modem port queueing, which is why
; you should call MEX instead of BDOS).  MEX uses function calls
; above about 244 for special overlay services (described below).
;
; Some sophisticated overlays may need to do file I/O; if so, use
; the PARSFN MEX call with a pointer to the FCB in DE to parse out
; the name.  This FCB should support a spare byte immediately pre-
; ceeding the actual FCB (to contain user # information).  If you've
; used MEX-10 for input instead of BDOS-10 (or you're parsing part
; of a SET command line that's already been input), then MEX will
; take care of DU specs, and set up the FCB accordingly.  There-
; after all file I/O calls done through the MEX service processor
; will handle drive and user with no further effort necessary on
; the part of the programmer.
;
MEX    EQU    0D00H        ;address of the service processor
INMDM    EQU    255        ;get char from port to A, CY=no more in 100 ms
TIMER    EQU    254        ;delay 100ms * reg B
TMDINP    EQU    253        ;B=# secs to wait for char, cy=no char
CHEKCC    EQU    252        ;check for ^C from KBD, Z=present
SNDRDY    EQU    251        ;test for modem-send ready
RCVRDY    EQU    250        ;test for modem-receive ready
SNDCHR    EQU    249        ;send a character to the modem (after sndrdy)
RCVCHR    EQU    248        ;recv a char from modem (after rcvrdy)
LOOKUP    EQU    247        ;table search: see CMDTBL comments for info
PARSFN    EQU    246        ;parse filename from input stream
BDPARS    EQU    245        ;parse baud-rate from input stream
SBLANK    EQU    244        ;scan input stream to next non-blank
EVALA    EQU    243        ;evaluate numeric from input stream
LKAHED    EQU    242        ;get nxt char w/o removing from input
GNC    EQU    241        ;get char from input, cy=1 if none
ILP    EQU    240        ;inline print
DECOUT    EQU    239        ;decimal output
PRBAUD    EQU    238        ;print baud rate
;
;
CONOUT    EQU    2        ;simulated BDOS function 2: console char out
PRINT    EQU    9        ;simulated BDOS function 9: print string
INBUF    EQU    10        ;input buffer, same structure as BDOS 10
;
;
CR    EQU    13
LF    EQU    10
;
;
    ORG    DIALV        ;OVERLAY THE DIALING VECTOR
    JMP    DIAL
;
    ORG    DISCV
    JMP    DISCIT        ;DISCONNECT VECTOR
;
;
; This is the DIAL routine called by MEX to dial a digit. The digit
; to be dialed is passed in the A register.  Note that two special
; codes must be intercepted as non-digits: 254 (start dial sequence)
; and 255 (end-dial sequence).  Mex will always call DIAL with 254
; in the accumulator prior to dialing a number.  Mex will also call
; dial with 255 in A as an indication that dialing is complete. Thus,
; the overlay may use these values to "block" the number, holding it
; in a buffer until it is completely assembled (in fact, that's the
; scheme employed here for the Racal Vadic).
;
; After the 254-start-dial sequence, MEX will call the overlay with
; digits, one-at-a-time.  MEX will make no assumptions about the dig-
; its, and will send each to the DIAL routine un-inspected (some modems,
; like the Smartmodem, allow special non-numeric characters in the
; phone number, and MEX may make no assumptions about these).
;
; After receiving the end-dial sequence (255) the overlay must take
; whatever end-of-dial actions are necessary *including* waiting for
; carrier at the distant end.  The overlay should monitor the keyboard
; during this wait (using the MEX keystat service call), and return
; an exit code to MEX in the A register, as follows:
;
;    0 - Carrier detected, connection established
;    1 - Far end busy (only for modems that can detect this condition)
;    2 - No answer (or timed out waiting for modem response)
;    3 - Keyboard abort (^C only: all others should be ignored)
;    4 - Error reported by modem
;
; <No other codes should be returned after an end-dial sequence>
;
; The overlay should not loop forever in the carrier-wait routine, but
; instead use either the overlay timer vector, or the INMDMV (timed 100
; ms character wait) service call routine.
;
; The DIAL routine is free to use any of the registers, but must return
; the above code after an end-dial sequence
;
    ORG    DIALOC
;
DIAL:    LHLD    DIALPT        ;FETCH POINTER
    CPI    254        ;START DIAL?
    JZ    STDIAL        ;JUMP IF SO
    CPI    255        ;END DIAL?
    JZ    ENDIAL        ;JUMP IF SO
;
; Not start or end sequence, must be a digit to be sent to the modem
;
    MOV    M,A        ;PUT CHAR IN BUFFER
    INX    H        ;ADVANCE POINTER
    SHLD    DIALPT        ;STUFF PNTR
    RET            ;ALL DONE
;
; Here on a start-dial sequence
;
STDIAL:    LXI    H,DIALBF    ;SET UP BUFFER POINTER
    SHLD    DIALPT
    RET
;
; Here on an end-dial sequence
;
ENDIAL:
    MVI    M,0        ; Terminate phone number string
CLEAR:
    MVI    C,INMDM        ; Clean out the data buffer in usart
    CALL    MEX
    JNC    CLEAR        ; Get all available
    CALL    IDLE        ; idle b-4 wakeup
    LXI    H,WAKEUP    ; Get modem's attention
    CALL    RVSEND        ; Send ^E,<cr>
    CALL    LFWAIT        ; First thing after ^E,<cr>
    RNZ            ; Return if time out
    CALL    LFWAIT        ; After "HELLO..."
    RNZ            ; Return if time out
    LXI    H,DCMD        ; Send "dial" command to modem
    CALL    RVSEND
    LXI    H,DIALBF    ; Point to number
    CALL    RVSEND        ; Send it to modem
    CALL    SENDCR        ; Send <cr> to terminate phone number
    RNZ
;
; Here starts the main loop waiting for messages from the modem
;  and interpreting them.  Some are just passed to the console
;  and others trigger a specific action.
;
DLOOP:
    LXI    H,RESPBF    ; Point to response buffer
    MVI    C,255        ; Long wait here
    CALL    CATCHR        ; Catch response from modem
    ORA    A        ; Zero return code ?
    JNZ    IDLE        ; No, disconnect and return error code
    MOV    A,B        ; Get character count from CATCHR
    ORA    A        ; Hope it isn't zero
    JZ    DLOOP        ; If it is, then ignore this response
    LXI    H,RESPBF    ; Point to string from modem
    LXI    D,RSPTBL    ; Point to valid response table
    CALL    COMPR        ; Find out which response we got
    MOV    A,B        ; Get return value
    CPI    255        ; No response match
    JNZ    DIAL05
NOANS:
    CALL    IDLE
    MVI    A,2        ;Tell MEX:no answer
    RET
ERRET:
    MVI    A,4        ; Error return to MEX
    JMP    IDLE        ; Disconnect and return error code
DIAL05:
    CPI    3        ; Failed call? probally no answer!
    JZ    NOANS        ; Error return
    CPI    1        ; Dialing message ?
    JNZ    DIAL10
    MVI    C,ILP
    CALL    MEX
    DB    'Dial..',0
    JMP    DLOOP
DIAL10:
    CPI    2        ; Ringing ?
    JNZ    DIAL15
    MVI    C,ILP
    CALL    MEX
    DB    'Ring..',0
    JMP    DLOOP
DIAL15:
    CPI    4        ; Answer tone ?
    JNZ    DIAL20
    MVI    C,ILP
    CALL    MEX
    DB    'Carrier..',0
    JMP    DLOOP
DIAL20:
    CPI    5        ; On line ?
    JNZ    DIAL25
    XRA    A        ; Return on line code to MEX
    RET
DIAL25:
    CPI    7        ; Busy ?
    JNZ    DIAL35
DIAL30:
    MVI    A,1        ; Return busy code to MEX
    JMP    IDLE        ; Disconnect and return error code
DIAL35:
    CPI    6        ; No dial tone?
    JNZ    DIAL40
    PUSH    B
    PUSH    D
    PUSH    H
    MVI    C,ILP
    CALL    MEX
    DB    'No dial tone..',cr,lf,0
    JMP    UABORT
DIAL40:
    CPI    8        ; Voice ?
    JNZ    ERRET        ; If there was a match not handled above
;
; Handle "VOICE" here
;
    CALL    SENDCR        ; <cr> ends the "voice" mode
    JMP    DIAL30        ; Abort and return busy code to MEX
;
; Disconnect vector is to disconnect modem from phone line
; whenever the ^J,N or when DSC is used.
;
DISCIT:
    LXI    H,QUITIT
    CALL    RVSEND
IDLE:
;
; Forces modem into idle state by sending "idle" command and
;  then toggling DTR using the user's DISCV entry.
; Preserves any return code that may be in register A.
;
    PUSH    PSW        ; Preserve any return code
    CALL    SENDCR        ; Abort any dialing taking place
    LXI    H,IDLCMD    ; Send idle message to modem
    CALL    RVSEND        ; idle command modifed to 'I'
    MVI    C,TIMER        ; Let's slow things down a bit
    MVI    B,1        ; 1/10 second.
    CALL    MEX
    POP    PSW        ; Retrieve return code
    RET

SENDCR:
;
; Sends a carriage return character to the modem and waits for a
;  line feed character to be returned.
;
    LXI    H,CRMSG        ; Send <cr> to modem
    CALL    RVSEND

; Note: execution falls through to LFWAIT
;
; Waits til the character from the modem is a line feed
; Returns the same codes as CATCHR.
;
LFWAIT:
    MVI    C,1        ; Up to one-Tenth second for <lf>
    LXI    H,RESPBF
    JMP    CATCHR        ; Use CATCHR to wait for <lf>



; Table of valid responses from modem
RSPTBL:
    DB    'HE',0        ; "hello..."
    DB    'DI',0        ; "dialing..."
    DB    'RI',0        ; "ringing..."
    DB    'FA',0        ; "failed call"
    DB    'AN',0        ; "answer tone"
    DB    'ON',0        ; "on line"
    DB    'NO',0        ; "no dial tone"
    DB    'BU',0        ; "busy"
    DB    'VO',0        ; "voice??"
    DB    0        ; Table terminator


COMPR:
; Compares a string of characters in memory to a table of
;  strings.  Each entry of the table must be terminated by
;  a zero byte, and the table must be terminated by another
;  zero byte.
; Inputs:  HL points to the string to look for
;       DE points to the table
; Output:  B contains the number of the table entry that
;         matches the string, and a 255 if no entry matched.
;
    MVI    B,0        ; Init index
CMPR05:
    MVI    C,2        ; Number of characters to try to match
CMPR10:
    LDAX    D        ; Fetch char from table
    CMP    M        ; Same as char in string ?
    JNZ    CMPR15        ; Jump if not this entry in table
    INX    H        ; Else, point to next char in string
    INX    D        ;  and next char in table entry
    DCR    C        ; Decrement counter of characters
    JNZ    CMPR10        ; Go check next char
    RET            ; B contains the index of match
CMPR15:
    INR    B        ; Increment index
CMPR20:
    INX    D        ; Next char in table
    LDAX    D        ; Get next char from table
    ORA    A        ; Is it last char in that entry ?
    JNZ    CMPR20        ; No, keep looking
    INX    D        ; Yes, then point to first char of next one
    LDAX    D        ; Now check for end of table
    ORA    A        ; Zero delimits table
    JNZ    CMPR05        ; Go check this table entry
    MVI    B,255        ; No match return code
    RET


CATCHR:
;
; Catch response from modem.
; Input:  HL pointing to buffer for characters from modem
;      C  delay allowed before timeout (multiples of 100ms)
; Output: Buffer contains the string received from modem with
;       any control characters filtered out.
;      C  count of characters received before <cr>
;      A  error code:  0 ==> normal return
;              2 ==> time out occurred
;              3 ==> user typed ^C
;
    MVI    B,0        ; Character counter
CRLOOP:
    MOV    D,C        ; Initialize count down timer
CRL05:
    PUSH    B        ; Save character counter
    PUSH    D        ; Save time out count down
    PUSH    H        ; Save buffer pointer
    MVI    C,CHEKCC    ; See if user typed ^C
    CALL    MEX
    JZ    UABORT        ; If yes, jump to user abort code
    MVI    C,INMDM        ; Else, continue
    CALL    MEX        ; Get char in 1ms if available
    POP    H        ; Restore working registers
    POP    D
    POP    B
    JC    NOCHAR        ; If no char in 1ms, handle it
    ANI    7FH        ; Mask any parity bit
    CPI    LF        ; End of line from modem ?
    JZ    EOL        ; If <lf> then end of line
    CPI    ' '        ; Filter unwanted characters
    JC    CRLOOP        ; Ignore control characters
    CPI    'z'+1        ; Nothing above lower case alpha's
    JNC    CRLOOP
    MOV    M,A        ; Here we have a valid character
    INX    H        ;  so save it and bump pointer
    INR    B        ; Increment character counter also
    JMP    CRLOOP        ; Go get the next one

;
; Handle no character from modem in 1ms
;
NOCHAR:
    DCR    D        ; Decrement time out counter
    JNZ    CRL05        ; If not to zero, wait some more
    MOV    C,B        ; Else, return with what we have now
    MVI    A,2        ; Time-out error code
    RET
;
; End of line from modem
;
EOL:
    MOV    C,B        ; Character count
    XRA    A        ; Return zero
    RET
;
; User abort from ^C
;
UABORT:
    CALL    IDLE        ; Reset modem
    POP    H        ; Since these are still on the stack
    POP    D
    POP    B
    MOV    C,B        ; Count of characters up to now
    MVI    A,3        ; User abort code
    RET

;
; Sends a string of characters pointed to by HL terminated by zero
;
RVSEND:
    MVI    C,SNDRDY    ; Get modem send status
    CALL    MEX
    JNZ    RVSEND        ; Wait for modem ready
    MOV    A,M        ; Get character
    INX    H        ; Point to next character
    ORA    A        ; Is this the terminator ?
    RZ            ; If yes, done
    MOV    B,A        ; Pass character in B
    MVI    C,SNDCHR    ; Let MEX send to modem
    CALL    MEX
    JMP    RVSEND

;
; DATA AREA
;
WAKEUP:    DB    'E'-40H,CR,0    ; String to wake up modem
IDLCMD:    DB    'I',CR,0    ; Idle command
DCMD:    DB    'D',0        ; Dial command to modem
CRMSG:    DB    CR,0        ; Note, this is end of DCMD
RESPBF:    DS    20        ; Response from modem
DIALBF:    DS    30        ; Phone number buffer
DIALPT:    DS    2        ; Dial position pointer
QUITIT:    DB    03,04,0        ; Disconnect modem codes
;
ENDm
;
EOL:
    MOV    C,B        ; Character count
    XRA    A        ; Return zero
    RET
;
; User abort fro