ftp.barnyard.co.uk/2015.02.ftp.barnyard.co.uk.tar/ftp.barnyard.co.uk/cpm/walnut-creek-CDROM/CPM/MEX/MXH-AM12.Z80

Text File | 2000-06-30 | 22KB | 771 lines

    TITLE    MXH-AM12 -- MEX Overlay for AMPRO LB

; MEX overlay for the Ampro Little Board Computer
;
;    New version for the XLR8 board
;
; Version 1.2  30 Oct 86
;  Changed to MXHAM12, added break send capability and SET BREAK.
;    -- Brian K. Uechi
;
;  Also changed to allow last cloned baud to be the default.
;    -- Dave VanHorn
;
; Version 1.1  07 Feb 1986
;  Changed to MXH-AM11 from MXO=AM10, added DCD & DTR support and
;  made LOADable from within MEX+    --Bob Connolly
;
; Version 1.0: 28 Nov 1984

REV    EQU    12        ;overlay revision level


; This is a MEX overlay file for the Ampro Computer.  It is designed
; to work with the modem connected to serial port 'B'.  It also
; requires the CTC and SIO parameter tables at the front of the
; Ampro bios, as well as the I/O initialization routine in the
; Ampro bios.  This is a non-standard bios call and if not present
; in the bios it must be duplicated in this overlay.

; Note that all overlays may freely use memory up to 0CFFH.  If the
; overlay must work with the MEX Smartmodem overlay (MXO-SMxx.ASM),
; the physical modem overlay should terminate by 0AFFH.

;------------------------------------------------------------

; Misc equates

NO    EQU    0
YES    EQU    0FFh
TPA    EQU    100h
CR    EQU    13
LF    EQU    10
TAB    EQU    9

; Ampro definitions

IOINT    EQU    57        ;BIOS call of initialization routine
SIOB    EQU    52h        ;relative location in bios
SIOB1    EQU    53h        ;Image in memory of SIO register 4
SIOB3    EQU    55h        ;Image in memory of SIO register 5
SIOB5    EQU    57h        ;Image in memory of SIO register 3
CT1    EQU    42h        ;CTC CTL reg

; port definitions

MODCTL    EQU    8Ch        ;modem control port B
MODDAT    EQU    88h        ;modem data port B

; bit definitions

MDRCVB    EQU    01h        ;modem receive bit (DAV)
MDRCVR    EQU    01h        ;modem receive ready
MDSNDB    EQU    04h        ;modem send bit
MDSNDR    EQU    04h        ;modem send ready bit

; 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

    ORG    TPA        ;we begin

    db    0c3h
    DS    2        ;MEX has a JMP START here

; The following variables are located at the beginning of the program
; to facilitate modification without the need of re-assembly. They will
; be moved in MEX 2.0.

PMODEM:    DB    NO        ;yes=PMMI modem \ / These 2 locations are not
SMODEM:    DB    YES        ;yes=Smartmodem / \ referenced by MEX
TPULSE:    DB    'T'        ;T=touch, P=pulse (not referenced by MEX)
CLOCK:    DB    40        ;clock speed x .1, up to 25.5 mhz.
MSPEED:    DB    6        ;sets display time for sending a file
                ;0=110    1=300  2=450  3=600  4=710
                ;5=1200 6=2400 7=4800 8=9600 9=19200
BYTDLY:    DB    5        ;default time to send character in
                ;terminal mode file transfer (0-9)
                ;0=0 delay, 1=10 ms, 5=50 ms, 9=90 ms
CRDLY:    DB    5        ;end-of-line delay after CRLF in terminal
                ;mode file transfer for slow BBS systems
                ;0=0 delay, 1=100 ms, 5=500 ms, 9=900 ms
COLUMS:    DB    5        ;number of directory columns
SETFL:    DB    YES        ;yes=user-defined SET command
SCRTST:    DB    YES        ;yes=if home cursor and clear screen    10Ch
                ;routine at CLRSCRN
    DB    0        ;was once ACKNAK, now spare
BAKFLG:    DB    NO        ;yes=make .BAK file
CRCDFL:    DB    YES        ;yes=default to CRC checking
                ;no=default to Checksum checking
TOGCRC:    DB    YES        ;yes=allow toggling of Checksum to CRC    110h
CVTBS:    DB    NO        ;yes=convert backspace to rub
TOGLBK:    DB    YES        ;yes=allow toggling of bksp to rub
ADDLF:    DB    NO        ;no=no LF after CR to send file in
                ;terminal mode (added by remote echo)
TOGLF:    DB    YES        ;yes=allow toggling of LF after CR
TRNLOG:    DB    YES        ;yes=allow transmission of logon
                ;write logon sequence at location LOGON
SAVCCP:    DB    YES        ;yes=do not overwrite CCP
LOCNXT:    DB    NO        ;yes=local cmd if EXTCHR precedes
                ;no=not local cmd if EXTCHR precedes
TOGLOC:    DB    YES        ;yes=allow toggling of LOCNXTCHR
LSTTST:    DB    YES        ;yes=allow toggling of printer on/off
                ;in terminal mode. Set to no if using
                ;the printer port for the modem
XOFTST:    DB    NO        ;yes=allow testing of XOFF from remote
                ;while sending a file in terminal mode
XONWT:    DB    NO        ;yes=wait for XON after sending CR while
                ;transmitting a file in terminal mode
TOGXOF:    DB    YES        ;yes=allow toggling of XOFF testing
IGNCTL:    DB    NO        ;yes=do not send control characters
                ;above CTL-M to CRT in terminal mode
                ;no=send any incoming CTL-char to CRT
EXTRA1:    DB    0        ;for future expansion
EXTRA2:    DB    0        ;for future expansion
BRKCHR:    DB    '@'-40H        ;^@ = Send a 300 ms. break tone
NOCONN:    DB    'N'-40H        ;^N = Disconnect from phone line
LOGCHR:    DB    'L'-40H        ;^L = Send logon
LSTCHR:    DB    'P'-40H        ;^P = Toggle printer
UNSVCH:    DB    'R'-40H        ;^R = Close input text buffer
TRNCHR:    DB    'T'-40H        ;^T = Transmit file to remote
SAVCHR:    DB    'Y'-40H        ;^Y = Open input text buffer
EXTCHR:    DB    '^'-40H        ;^^ = Send next character        127h

    ds    2        ;make addresses right

; Low-level modem I/O routines: this will be replaced with
; a jump table in MEX 2.0 (you can insert jumps here to longer
; routines if you'd like ... I'd recommend NOT putting part of
; a routine in this area, then jumping to the rest of the routine
; in the non-fixed area; that will complicate the 2.0 conversion)

INCTL1:    IN    A,(MODCTL)    ;in modem control port            12Ah
    RET
    DB    0,0,0,0,0,0,0    ;spares if needed for non-PMMI

OTDATA:    OUT    (MODDAT),A    ;out modem data port            134h
    RET
    DB    0,0,0,0,0,0,0    ;spares if needed for non=PMMI

INPORT:    IN    A,(MODDAT)    ;in modem data port            13Eh
    RET
    DB    0,0,0,0,0,0,0    ;spares if needed for non-PMMI

; Bit-test routines.  These will be merged with the above
; routines in MEX 2.0 to provide a more reasonable format

MASKR:    AND    MDRCVB        ;bit to test for receive ready        148h
    RET

TESTR:    CP    MDRCVR        ;value of receive bit when ready    14Bh
    RET

MASKS:    AND    MDSNDB        ;bit to test for send ready        14Eh
    RET

TESTS:    CP    MDSNDR        ;value of send bit when ready        151h
    RET


dcdtst:    jp    dcdvec        ;data carrier detect            154h
rngdet:    jp    rngvec        ;ring-detect                157h

    db    0,0,0,0,0

; Special modem function jump table: if your overlay cannot handle
; some of these, change the jump to "DS 3", so the code present in
; MEX will be retained.  Thus, if your modem can't dial, change the
; JMP PDIAL at DIALV to DS 3, and MEX will print a "not-implemented"
; diagnostic for any commands that require dialing.

; DIALV  dials the digit in A. See the comments at PDIAL for specs.

; DISCV  disconnects the modem

; GOODBV is called just before MEX exits to CP/M.  If your overlay
;        requires some exit cleanup, do it here.

; INMODV is called when MEX starts up; use INMODV to initialize the modem.

; NEWBDV is used for phone-number baud rates and is called with a baud-rate
;        code in the A register, value as follows:

;     A=0:   110 baud       A=1:   300 baud      A=2:   450 baud
;     A=3:   600 baud       A=4:   710 baud      A=5:  1200 baud
;     A=6:  2400 baud       A=7:  4800 baud      A=8:  9600 baud
;
;        If your overlay supports the passed baud rate, it should store the
;     value passed in A at MSPEED (107H), and set the requested rate. If
;     the value passed is not supported, you should simply return (with-
;     out modifying MSPEED) -or- optionally request a baud-rate from the
;     user interactively.
;
; NOPARV is called at the end of each file transfer; your overlay may simply
;     return here, or you may want to restore parity if you set no-parity
;     in the following vector (this is the case with the PMMI overlay).

; PARITV is called at the start of each file transfer; your overlay may simply
;     return here, or you may want to enable parity detection (this is the
;     case with the PMMI overlay).

; SETUPV is the user-defined command ... to use this routine to build your own
;     MEX command, set the variable SETFL (117H) non-zero, and add your SET
;     code.  You can use the routine presented in the PMMI overlay as a
;     guide for parsing, table lookup, etc.

; SPMENU is provided only for MDM compatibility, and is not used by MEX 1.0 for
;     any purpose (it will be gone in MEX 2).

; VERSNV is called immediately after MEX prints its sign-on message at cold
;     startup -- use this to identify your overlay in the sign-on message
;     (include overlay version number in the line).
; BREAKV is provided for sending a BREAK (<ESC>-B in terminal mode).  If your
;     modem doesn't support BREAK, or you don't care to code a BREAK rou-
;     tine, you may simply execute a RET instruction.
;
smdisc:    ds    3        ;smartmodem disc (not here}        15Fh
DIALV:    DS    3        ;dial digit in A (see info at PDIAL)    162h
DISCV:    jp    drdtr        ;disconnect the modem            165h
GOODBV:    DS    3        ;called before exit to CP/M        168h
INMODV:    JP    NITMOD        ;initialization. Called at cold-start    16Bh
NEWBDV:    JP    PBAUD        ;set baud rate                16Eh
NOPARV:    JP    NOPAR        ;set modem for no-parity        171h
PARITV:    JP    PARITY        ;set modem parity            174h
SETUPV:    JP    SETCMD        ;SET cmd: jump to a RET if no SETCMD    177h
SPMENV:    DS    3        ;not used with MEX            17Ah
VERSNV:    JP    SYSVER        ;Overlay's voice in the sign-on message    17Dh
BREAKV:    jp    SBREAK        ;1.2| send a break            180h

; The following jump vector provides the overlay with access to special
; routines in the main program (retained and supported in the main pro-
; gram for MDM overlay compatibility). These should not be modified by
; the overlay.

; Note that for MEX 2.0 compatibility, you should not try to use these
; routines, since this table will go away with MEX 2.0 (use the MEX
; service call processor instead).

ILPRTV:    DS    3        ;replace with MEX function 9        183h
INBUFV:    DS    3        ;replace with MEX function 10        186h
ILCMPV:    DS    3        ;replace with table lookup funct. 247    189h
INMDMV:    DS    3        ;replace with MEX function 255        18Ch
NXSCRV:    DS    3        ;not supported by MEX (returns w/no action)
TIMERV:    DS    3        ;replace with MEX function 254        192h

; Clear/screen and clear/end-of-screen. Each routine must use the
; full 9 bytes alloted (may be padded with nulls).

; These routines (and other screen routines that MEX 2.0 will sup-
; port) will be accessed through a jump table in 2.0, and will be
; located in an area that won't tie the screen functions to the
; modem overlay (as the MDM format does).

CLREOS:    LD    DE,EOSMSG    ;                    195h
    LD    C,PRINT
    CALL    MEX
    RET

CLS:    LD    DE,CLSMSG    ;null unless patched              19Eh
    LD    C,PRINT
    CALL    MEX
    RET

    org    200h        ; area above is reserved

EOSMSG:    DB    27,89,0,0,0,'$'

CLSMSG:    DB    27,42,0,0,0,'$'

NOPAR:    RET

PARITY:    RET

DRDTR:    LD    A,5        ; Setup to write register 5
    OUT    (MODCTL),A
    LD    A,68H        ; Clear RTS causing shutdown
    OUT    (MODCTL),A
    RET

dcdvec:    ld    a,10h        ;reset status
    out    (modctl),a    ;  0=NO CARRIER  255=CARRIER
    in    a,(modctl)    ;  254=NOT SUPPORTED
    and    20h        ;dcd from modem must
    ret    z        ; be connected to
    or    0ffh        ; cts (ampro) else
    ret            ; return 0feh (unsupported)

rngvec:    ld    a,0feh
    ret

NITMOD:    LD    A,(Mspeed)    ;set baud to last cloned rate

;------------------------------------------------------------------

PBAUD:    PUSH    HL        ;don't alter anybody
    PUSH    DE
    PUSH    BC
    LD    E,A        ;code to DE
    LD    D,0
    LD    HL,BAUDTB    ;offset into table
    ADD    HL,DE
    LD    A,(HL)        ;fetch code
    OR    A        ;0? (means unsupported code)
    SCF            ;return error for STBAUD caller
    JP    Z,PBEXIT    ;exit if so
    LD    (BSAVE1),A    ;save it
    LD    A,E        ;get speed code back
    LD    (MSPEED),A    ;make it current
    LD    HL,BAUDTX    ;offset into second table
    ADD    HL,DE
    LD    A,(HL)        ;get second value
    LD    (BSAVE2),A    ;save it also

    LD    HL,(1)        ;get location of bios
    LD    L,CT1        ;add 42 to reach CT1 in i/o table
    LD    A,47h
    LD    (HL),A
    INC    HL        ;move to next location
    LD    A,(BSAVE1)    ;get first table value
    LD    (HL),A        ;store it
    LD    A,(BSAVE2)    ;get second table value
    LD    B,A        ;and save it
    LD    L,SIOB1        ;move ahead to siob+1 values
    LD    A,(HL)        ;get current value
    AND    3Fh
    OR    B        ;or it with second value
    LD    (HL),A        ;store it in work table
    INC    HL
    INC    HL
    LD    A,(HL)        ;get last value and make
    OR    80h        ;sure msb is set
    LD    (HL),A        ;put it back in working table
    CALL    IOINIT        ;do the initialization
    SCF
    CCF            ;return no error for STBAUD

PBEXIT:    POP    BC        ;all done
    POP    DE
    POP    HL
    RET

IOINIT    LD    A,IOINT        ;offset into bios jump table
    LD    HL,(1)        ;address of bios in HL
    LD    L,A        ;add offset
    JP    GOHL        ;and go there with auto return

; table of baud rate divisors for supported rates

BAUDTB:    DB    0,208,139,208,0,104    ; 110, 300, 450, 600, 710,1200
    DB    52,26,13,0        ;2400,4800,9600,19200

BAUDTX:    DB    0,80h,80h,40h,0,40h
    DB    40h,40h,40h,0

BSAVE1    DB    0        ;current setting from
BSAVE2    DB    0        ;tables - uninitialized

; Sign-on message

SYSVER:    LD    DE,SOMESG
    LD    C,PRINT
    CALL    MEX
    RET

SOMESG:    DB    'Ampro Overlay Version '
    DB    REV/10+'0'
    DB    '.'
    DB    REV MOD 10+'0'
    DB    CR,LF
    DB    CR,LF
    DB    'Set Break and ^J@ Break enabled.'
    DB    CR,LF,'$'

; Newline on console

CRLF:    LD    A,CR
    CALL    TYPE
    LD    A,LF        ;fall into TYPE

; type char in A on console

TYPE:    PUSH    HL        ;save 'em
    PUSH    DE
    PUSH    BC
    LD    E,A        ;align output character
    LD    C,CONOUT    ;print via MEX
    CALL    MEX
    POP    BC
    POP    DE
    POP    HL
    RET

; Data area

;------------------------------------------------------------

; The remainder of this overlay implements a very versatile
; SET command -- if you prefer not to write a SET for your
; modem, you may delete the code from here to the END statement.

; Control is passed here after MEX parses a SET command.

SETCMD:    LD    C,SBLANK    ;any arguments?
    CALL    MEX
    JP    C,SETSHO    ;if not, go print out values
    LD    DE,CMDTBL    ;parse command
    CALL    TSRCH        ;from table
    PUSH    HL        ;any address on stack
    RET    NC        ;if we have one, execute it
    POP    HL        ;nope, fix stack

SETERR:    LD    DE,SETEMS    ;print error
    LD    C,PRINT
    CALL    MEX
    RET

SETEMS:    DB    CR,LF,'SET command error',CR,LF,'$'

; SET command table ... note that tables are constructed of command-
; name (terminated by high bit=1) followed by word-data-value returned
; in HL by MEX service processor LOOKUP.  Table must be terminated by
; a binary zero.

; Note that LOOKUP attempts to find the next item in the input stream
; in the table passed to it in HL ... if found, the table data item is
; returned in HL; if not found, LOOKUP returns carry set.

CMDTBL:    DB    '?'+80H        ;"set ?"
    DW    STHELP
    DB    'BAU','D'+80H    ;"set baud"
    DW    STBAUD
    DB    'BIT','S'+80H    ;"set bits"
    DW    STBITS
    DB    'PARIT','Y'+80H    ;"set parity"
    DW    STPAR
    DB    'STO','P'+80H    ;"set stop"
    DW    STSTOP
    DB    'SHAK','E'+80H    ;"set shake"
    DW    STSHAK
    DB    'BREA','K'+80H    ;1.2| "set break"
    DW    SBREAK        ;1.2|

    DB    0        ;<<=== table terminator

; SET <no-args>: print current statistics

SETSHO:    LD    HL,SHOTBL    ;get table of SHOW subroutines
SETSLP:    LD    E,(HL)        ;get table address
    INC    HL
    LD    D,(HL)
    INC    HL
    LD    A,D        ;end of table?
    OR    E
    RET    Z        ;exit if so
    PUSH    HL        ;save table pointer
    EX    DE,HL        ;adrs to HL
    CALL    GOHL        ;do it
    CALL    CRLF        ;print newline
    LD    C,CHEKCC    ;check for console abort
    CALL    MEX
    POP    HL        ;it's done
    JP    NZ,SETSLP    ;continue if no abort
    RET

GOHL:    JP    (HL)

; table of SHOW subroutines

SHOTBL:    DW    BDSHOW
    DW    BITSH
    DW    PARSH
    DW    STPSH
    DW    SHKSH
    DW    0        ;<<== table terminator

; SET ?  processor

STHELP:    LD    DE,HLPMSG
    LD    C,PRINT
    CALL    MEX
    RET

; The help message

HLPMSG:    DB    CR,LF,'SET command, Ampro version:',CR,LF
    DB    CR,LF,'  >SET BAUD 300, 450, 600, 1200, 2400, 4800, or 9600.'
    DB    CR,LF,'  >SET BITS 5, 6, 7, or 8.'
    DB    CR,LF,'  >SET PARITY ODD, EVEN, or NONE.'
    DB    CR,LF,'  >SET STOP 1, or 2.'
    DB    CR,LF,'  >SET SHAKE ON, or OFF.'
    DB    CR,LF,'  >SET BREAK  (Only used from mex readfiles to send'
    DB    CR,LF,'               break in an auto-logon environment.)'
    DB    CR,LF,CR,LF,'$'

; SET BAUD processor

STBAUD:    LD    C,BDPARS    ;function code
    CALL    MEX        ;let MEX look up code
    JP    C,SETERR    ;invalid code
    CALL    PBAUD        ;no, try to set it
    JP    C,SETERR    ;not-supported code

BDSHOW:    CALL    ILPRT        ;display baud
    DB    '  Baud rate: ',0
    LD    A,(MSPEED)
    LD    C,PRBAUD    ;use MEX routine
    CALL    MEX
    RET

; SET BITS processor

STBITS:    LD    DE,BITTBL    ;load lookup table
    CALL    TSRCH        ;look for 7 or 8
    JP    C,SETERR    ;if not found
    LD    C,L        ;save selection value
    LD    HL,(1)        ;get bios address
    LD    L,SIOB3        ;move to siob+3
    LD    A,(HL)        ;wr5 info
    AND    9Fh        ;mask
    OR    C        ;add selection
    LD    (HL),A        ;store it
    LD    A,C        ;get selection
    RLA
    LD    C,A        ;shift selection left
    LD    L,SIOB5        ;move to siob+5
    LD    A,(HL)        ;wr3 info
    AND    3Fh        ;mask
    OR    C
    LD    (HL),A        ;store it
    CALL    IOINIT        ;do it.

BITSH:    CALL    ILPRT
    DB    '  Data bits: ',0
    LD    HL,(1)        ;get bios location
    LD    L,SIOB3        ;move to siob+3
    LD    A,(HL)        ;get current value
    AND    60h
    CP    60h
    JP    Z,BITSH8
    CP    20h
    JP    Z,BITSH7
    CP    40h
    JP    Z,BITSH6
    CALL    ILPRT
    DB    '5',0        ;show a 5
    RET

BITSH6    CALL    ILPRT
    DB    '6',0        ;show a 6
    RET

BITSH7    CALL    ILPRT
    DB    '7',0        ;show a 7
    RET

BITSH8:    CALL    ILPRT
    DB    '8',0
    RET

BITTBL:    DB    '5'+80h
    DW    00h
    DB    '6'+80h
    DW    40h
    DB    '7'+80h
    DW    20h
    DB    '8'+80h
    DW    60h
    DB    0

STPAR:    LD    DE,PARTBL
    CALL    TSRCH
    JP    C,SETERR
    LD    C,L
    LD    HL,(1)        ;get bios address
    LD    L,SIOB1        ;go to siob+1
    LD    A,(HL)
    AND    0FCh
    OR    C
    LD    (HL),A
    CALL    IOINIT

PARSH:    CALL    ILPRT
    DB    '     Parity: ',0
    LD    HL,(1)        ;get bios address
    LD    L,SIOB1
    LD    A,(HL)
    AND    03h        ;mask
    CP    01h        ;check for none
    JP    Z,PARSHO
    CP    03h
    JP    Z,PARSHE

    CALL    ILPRT
    DB    'none',0
    RET

PARSHO    CALL    ILPRT
    DB    'odd',0
    RET

PARSHE:    CALL    ILPRT
    DB    'even',0
    RET

PARTBL:    DB    'OD','D'+80h
    DW    01h
    DB    'EVE','N'+80h
    DW    03h
    DB    'NON','E'+80h
    DW    00h
    DB    0

STSTOP:    LD    DE,STPTBL
    CALL    TSRCH
    JP    C,SETERR
    LD    C,L
    LD    HL,(1)        ;get bios address
    LD    L,53h        ;shift to bios+1
    LD    A,(HL)
    AND    0F3h
    OR    C
    LD    (HL),A
    CALL    IOINIT

STPSH:    CALL    ILPRT
    DB    '  Stop bits: ',0
    LD    HL,(1)        ;get bios address
    LD    L,53h        ;shift to bios+1
    LD    A,(HL)
    AND    0Ch
    CP    0Ch
    JP    Z,STPSH2
    CALL    ILPRT
    DB    '1',0
    RET

STPSH2:    CALL    ILPRT
    DB    '2',0
    RET

STPTBL:    DB    '1'+80h
    DW    04h
    DB    '2'+80h
    DW    0Ch
    DB    0

STSHAK:    LD    DE,SHKTBL    ;get handshake table
    CALL    TSRCH        ;search it for parameter
    JP    C,SETERR    ;if not found
    LD    C,L        ;temp store value in C
    LD    HL,(1)        ;get location of BIOS
    LD    L,6Dh        ;location of HSB in bios
    LD    (HL),C        ;put new value in it

SHKSH:    CALL    ILPRT
    DB    ' Hand Shake: ',0
    LD    HL,(1)        ;get bios location
    LD    L,6DH        ;location of HSB in bios
    LD    A,(HL)        ;get current value
    CP    1
    JP    Z,SHKSHY    ;show a yes
    CALL    ILPRT
    DB    'off',0
    RET

SHKSHY    CALL    ILPRT
    DB    'on',0
    RET

SHKTBL    DB    'OF','F'+80h
    DW    0
    DB    'O','N'+80h
    DW    1
    DB    0

;----------------------------------------------------------

; This routine sends a 300 ms break.    1.2| vv
;
SBREAK:    LD    HL,(1)        ;HL = A(bios jump table)
    LD    L,SIOB3        ;offset to memory image of SIO reg 5
    LD    A,(HL)        ;get memory image
    PUSH    HL
    PUSH    AF        ;save address and original value for later
    OR    10H        ;set SEND BREAK bit in SIO reg 5
    LD    (HL),A        ;put it back in memory
    CALL    IOINIT        ;update SIO so it sends break
    LD    DE,BRKMSG    ;Tell user about break
    LD    C,PRINT
    CALL    MEX
    LD    B,3        ;leave break on for 300 ms
    LD    C,TIMER
    CALL    MEX
    POP    AF        ;restore original value of
    POP    HL        ;...memory image of SIO reg 5
    LD    (HL),A
    CALL    IOINIT        ;update SIO
    RET

BRKMSG:    DB    '[Sending Break]','$'

;----------------------------------------------------------

; Compare next input-stream item in table @DE; CY=1
; if not found, else HL=matched data item

TSRCH:    LD    C,LOOKUP    ;get function code
    JP    MEX        ;pass to MEX processor

; Print in-line message ... blows away C register

ILPRT:    LD    C,ILP        ;get function code
    JP    MEX        ;go do it

;------------------------------------------------------------

; End of AMPRO MEX modem overlay

;------------------------------------------------------------

    END