CP/M/CPM_CDROM.iso/cpm/mex/mxo-rt10.asm

Assembly Source File | 1994-07-13 | 14KB | 440 lines

    TITLE    'MEX RACAL-VADIC VA3451 AUTO DIAL - V1.0'
;
; (DELETE ABOVE TITLE LINE IF ASSEMBLING WITH ASM)
;
; MXO-RT10.ASM  Original release 6/13/84
;
; Racal Vadic VA3451 overlay for MEX: revision 1.0
;  Written 13 June 1984 by Dave Mabry
;  Adapted using information and excerpts from Ron Fowler's
;   overlay for the PMMI modem.
;
; Please leave any bug reports or requests on TCBBS in Dearborn,
;  Michigan (313-846-6127) or Royal Oak RCPM (313-759-6569)
;  or call me at 313-956-5703 (voice).        mabry
;
; Note that unlike the Hayes modem, the Racal Vadic does not
;  have an ascii command that will cause a disconnect.  Therefore
;  for that feature of MEX to work properly, your normal overlay
;  for your machine must be able to toggle DTR in the DISCV routine.
;
; This overlay will work with any modem overlay that terminates
; prior to 0B00H
;
; Note: For the disconnect to work properly, you MUST have DISCV
;    implemented in your normal machine overlay.  This file
;    is overlayed in addition to your overlay.
;    Also, your overlay MUST have the entry point NEWBDV that
;    allows this program to set the baud rate by passing a
;    single byte parameter in the A register.
;    See Ron Fowler's overlay for the GodBout S-100 board for
;    examples of these routines.
;
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
;
MSPEED    EQU    107H        ; Variable in hardware overlay
NEWBDV    EQU    16EH        ; Entry in overlay to set baud rate
;
;
CR    EQU    13
LF    EQU    10
;
;
    ORG    DIALV        ;OVERLAY THE DIALING VECTOR
    JMP    DIAL
;
;
; 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
    XRA    A
    STA    BDFLAG        ; Zero BDFLAG
    LDA    MSPEED        ; Get baud rate set by MEX
    CPI    5        ; 1200 baud ???
    JZ    CLEAR        ; Nothing to do if 1200 baud
    STA    BDSAVE        ; Save baud rate locally
    MVI    A,TRUE        ; Else, set flag
    STA    BDFLAG
    MVI    A,1        ; If not 1200 baud then set 300
    CALL    NEWBDV        ;  baud for dialing
CLEAR:
    MVI    C,INMDM        ; Clean out the data buffer in usart
    CALL    MEX
    JNC    CLEAR        ; Get all available
    LXI    H,WAKEUP    ; Get modem's attention
    CALL    RVSEND
    CALL    STWAIT        ; After "HELLO..."
    LXI    H,DCMD        ; Send "dial" command to modem
    CALL    RVSEND
    CALL    SENDCR        ; Terminate dial command
    LXI    H,DIALBF    ; Point to number
    CALL    RVSEND        ; Send it to modem
    CALL    SENDCR        ; Send <cr> to terminate phone number
    LXI    H,CRMSG        ; Second <cr> to initiate dialing
    CALL    RVSEND
;
; 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    RETRN        ; No, 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
ERRET:
    MVI    A,2        ; Timed out waiting for answer
    JMP    IDLE        ; Disconnect and return error code
DIAL05:
    CPI    2        ; Failed call ?
    JZ    ERRET        ; Error return
    CPI    1        ; Dialing message ?
    JNZ    DIAL10
    MVI    C,ILP
    CALL    MEX
    DB    'Dialing...',0
    JMP    DLOOP
DIAL10:
    CPI    3        ; On line ?
    JNZ    ERRET
    XRA    A        ; Return on line code to MEX
RETRN:
    PUSH    PSW        ; Save return code
RET03:
    LDA    BDFLAG        ; See if we have to reset baud rate
    ORA    A
    JZ    RET05        ; Return if no
    LDA    BDSAVE        ; Get saved rate code
    CALL    NEWBDV        ; Set old baud again
RET05:
    POP    PSW        ; Get return code
    RET

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    DISCV        ; Make sure modem disconnects
    LXI    H,IDLCMD    ; Send idle command
    CALL    RVSEND
    JMP    RET03

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,10        ; Up to one second for <lf>
    LXI    H,RESPBF
    JMP    CATCHR        ; Use CATCHR to wait for <lf>

STWAIT:
    MVI    C,INMDM        ; Get one character from modem
    CALL    MEX
    JC    STWAIT        ; If time out, wait
    CPI    '*'        ; Is it the "*" prompt ?
    JNZ    STWAIT
    RET


; Table of valid responses from modem
RSPTBL:
    DB    'HE',0        ; "hello..."
    DB    'DI',0        ; "dialing..."
    DB    'FA',0        ; "failed call"
    DB    'ON',0        ; "on line"
    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
    MOV    A,B        ; Initialize space flag
    STA    SPFLAG
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    ' '        ; End of "DIALING:  "
    JZ    CRSPC        ; Handle space character
    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
;
; Handle space character, two in a row means the end of the
;  modem response "DIALING:  ".
;
CRSPC:
    LDA    SPFLAG        ; Get space flag
    ORA    A
    JNZ    EOL        ; This must be the second one in a row
    CMA            ; Otherwise, set the flag, it is the
    STA    SPFLAG        ;  first one, flag it
    JMP    CRLOOP        ; Loop for more characters
;
; User abort from ^C
;
UABORT:
    CALL    IDLE        ; Force disconnect
    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:
    PUSH    H        ; Save memory pointer
RV05:
    MVI    C,SNDRDY    ; Get modem send status
    CALL    MEX
    JNZ    RV05        ; Wait for modem ready
    MVI    B,1        ; Wait 1ms for modem software uart
    MVI    C,TIMER
    CALL    MEX
    POP    H        ; Restore pointer
    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
SPFLAG:    DS    1        ; Space flag for catch response routine
BDFLAG:    DS    1        ; True for 450 or 600 baud
BDSAVE:    DS    1        ; Save for MSPEED code for 450 or 600
RESPBF:    DS    20        ; Response from modem
DIALBF:    DS    30        ; Phone number buffer
DIALPT:    DS    2        ;DIAL POSITION POINTER
;
    END