; Title 'MEX Overlay for the TeleVideo Computer Version 1.3'
;
REV EQU 13 ;OVERLAY REVISION LEVEL
;
;
; MEX Overlay for TeleVideo TS-802H Computers, use MXM-2400
; external overlay with this one to support SSET commands.
;
; A full-featured SET command processor is implemented.
; The following table outlines the SET command options:
;
; SET Command
;
; BAUD <RATE> Set modem to Baud rate specified.
; Baud rates supported are 110, 300,
; 600, 1200, 2400, 4800, 9600, 19200
;
; PARITY Set Parity to Odd, Even, or Off
; STOPBITS Set number of Stop Bits to 1, 1.5, 2
; LENGTH Set word length to 5, 6, 7, 8
;
; This overlay includes the smartmodem dialing routine from
; MXO-SM13.ASM by Ron Fowler which has been slightly modified
; to allow programmable delay for answer. (Note that this is
; different from the "ATS7=nn".).
;
; This overlay is intended to be fully compatible with the
; MEX structure and should be readily upward compatible with
; the predicted MEX 2.0.
;
; Calling conventions for the various overlay entry points
; are detailed more fully in the PMMI overlay (MXO-PMxx.ASM,
; where xx=revision number).
;
; History:
;
; 08/16/85 1.3 Stripped out Smartmodem stuff so overlay can be
; used with MXM-2400 overlay for USR/Hayes 2400s.
; -- Kim Levitt
;
; 12/19/84 1.0 Created new Televideo overlay from MXO-KPS3 overlay
; Fixed break bug while I was at it..
; -- Kim Levitt
;
; Credits:
;
; M7KP-1 overlay structure by Irv Hoff
; Parity, Length and Stopbits routines by Norm Saunders
; MXO-KP overlay structure by John Smith
; Art work by Terry Carroll
; Bug fix/feature added by Kim Levitt
; Based on an idea by an inspired hacker
; Music by John Williams
; Directed by Stanley Kubrick
;
;------------------------------------------------------------
;
; Miscellaneous equates
;
NO EQU 0
YES EQU 0FFH
;
TPA EQU 100H
;
CR EQU 13
LF EQU 10
TAB EQU 9
;
; Televideo port definitions
;
EXPORT EQU 20H ;base external port
EXTCT1 EQU EXPORT+2 ;external modem status port
EXTDAT EQU EXPORT ;external modem data port
BAUDRP EQU 08H ;external modem baud rate port
;
; Z80 SIO 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
;
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
;
DCONIO EQU 6 ;BDOS Direct Console IO function #
DCONIN EQU 0FFH ;BDOS DCONIO Flag for input
BDOS EQU 5 ;BDOS Function caller
;
;
ORG TPA ;we begin
;
DS 3 ;MEX has a JMP START here
;
DS 2 ;not used by MEX
TPULSE: DB 'T' ;T=touch, P=pulse (Used by this overlay)
CLOCK: DB 46 ;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
;routine at CLRSCRN
DB 0 ;was once ACKNAK, now spare
BAKFLG: DB YES ;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
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 NO ;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
;
DS 2 ;not used
;
; Low-level modem I/O routines.
;
INCTL1: JMP INC ;in modem control port
DB 0,0,0,0,0,0,0 ;spares if needed for non-PMMI
;
OTDATA: JMP OUTD ;out modem data port
DB 0,0,0,0,0,0,0 ;spares if needed for non=PMMI
;
INPORT: JMP IND ;in modem data port
DB 0,0,0,0,0,0,0 ;spares if needed for non-PMMI
;
; Bit-test routines.
;
MASKR: ANI MDRCVB ! RET ;bit to test for receive ready
TESTR: CPI MDRCVR ! RET ;value of receive bit when ready
MASKS: ANI MDSNDB ! RET ;bit to test for send ready
TESTS: CPI MDSNDR ! RET ;value of send bit when ready
;
DS 12
;
LOGON: DS 2 ;needed for MDM compat, not ref'd by MEX
DIALV: RET!NOP!NOP ;need MXM overlay for modem for this
DISCV: JMP DISCON
GOODBV: JMP GOODBYE ;called before exit to CP/M
INMODV: JMP NITMOD ;initialization. Called at cold-start
NEWBDV: JMP PBAUD ;set baud rate
NOPARV: RET!NOP!NOP ;set modem for no-parity
PARITV: RET!NOP!NOP ;set modem parity
SETUPV: JMP SETCMD ;SET cmd: jump to a RET if you don't write SET
SPMENV: RET!NOP!NOP ;not used with MEX
VERSNV: JMP SYSVER ;Overlay's voice in the sign-on message
BREAKV: JMP SBREAK ;send a break
;
; MDM calls supported in MEX 1.0 but not recommended for use.
;
ILPRTV: DS 3 ;replace with MEX function 9
INBUFV: DS 3 ;replace with MEX function 10
ILCMPV: DS 3 ;replace with table lookup funct. 247
INMDMV: DS 3 ;replace with MEX function 255
NXSCRV: DS 3 ;not supported by MEX (returns w/no action)
TIMERV: DS 3 ;replace with MEX function 254
;
CLREOS: LXI D,EOSMSG
MVI C,PRINT
CALL MEX
RET
;
CLS: LXI D,CLSMSG
MVI C,PRINT
CALL MEX
RET
;
;------------------------------------------------------------
;
; end of fixed area
;
;------------------------------------------------------------
;
; Low level modem routine area
;
INC: MVI A,10H
OUT EXTCT1
IN EXTCT1
RET
;
IND: IN EXTDAT
RET
;
OUTD: OUT EXTDAT
RET
;
; Print out the overlay version
;
SYSVER: CALL MILP
DB 'TeleVideo TS-802H Overlay -- Version '
DB REV/10+'0'
DB '.'
DB REV MOD 10+'0'
DB CR,LF,CR,LF
DB 0
RET
;
; Break, disconnect and goodbye routines
;
SBREAK: MVI A,5
OUT EXTCT1
LDA REG5
ORI 9AH ;set break + RTS/DTR/TXEN
OUT EXTCT1
MVI B,3 ;DELAY 300 MS.
CALL MTIME
MVI A,5 ;then re-address WR5
OUT EXTCT1
LDA REG5 ;get current REG5 values
OUT EXTCT1 ;and restore/stop break
RET
;
; Disconnect Routine
;
DISCON:
MVI A,5
OUT EXTCT1 ;SEND TO THE STATUS PORT
MVI A,68H ;TURN OFF DTR/RTS
OUT EXTCT1
MVI B,10 ;DELAY 1 SEC.
CALL MTIME
MVI A,5
OUT EXTCT1
MVI A,0EAH ;TURN 'EM BACK ON AGAIN
OUT EXTCT1
RET
;
; GOODBYE routines are called by MEX prior to exit to CP/M
;
GOODBYE: RET ;NOTE: EXIT TO CP/M WITH NO CHANGE TO
;CONNECT STATUS OR SETTINGS (PARITY, ETC)
;
; Initialize RS-232 port, Smartmodem, and default modes.
;
NITMOD: CALL INC ;SEE IF MODEM IS CONNECTED, I.E., RETURNING
ANI 08H ; TO ACTIVE MODEM FROM CPM
RNZ ;SKIP IF CONNECTED
CALL NITSIO
LDA MSPEED ;Get default baud rate
CALL PBAUD ;Set default baud rate
RET ;Return
;
; Initialize the Zilog SIO chip
;
NITSIO: MVI A,00H ;Select reg. 0
OUT EXTCT1
LDA REG0 ;Command byte
OUT EXTCT1
MVI A,04H ;Select reg. 4
OUT EXTCT1
LDA REG4 ;Receive/transmit control byte
OUT EXTCT1
MVI A,03H ;Select reg. 3
OUT EXTCT1
LDA REG3 ;Receiver logic byte
OUT EXTCT1
MVI A,05H ;Select reg. 5
OUT EXTCT1
LDA REG5 ;Transmitter logic byte
OUT EXTCT1
RET
;
; Set command processor
;
SETCMD: MVI C,SBLANK ;ANY ARGUMENTS?
CALL MEX
JC SETSHO ;IF NOT, DISPLAY DEFAULT(S)
LXI D,CMDTBL
MVI C,LOOKUP
CALL MEX ;PARSE THE ARGUMENT
PUSH H ;SAVE ANY PARSED ARGUMENTS ON STACK
RNC ;IF WE HAVE ONE, RETURN TO IT
POP H ;OOPS, INPUT NOT FOUND IN TABLE
SETERR: LXI D,SETEMS
MVI C,PRINT
CALL MEX
CALL CRLF
RET
SETEMS: DB CR,LF,'SET command error',CR,LF,'$'
;
; Argument table
;
CMDTBL: DB '?'+80H ; HELP
DW SETHELP
DB 'BAU','D'+80H ; SET BAUD
DW STBAUD
DB 'PARIT','Y'+80H ; SET PARITY
DW STPRTY
DB 'STOPBIT','S'+80H ; SET STOPBITS
DW STSTOP
DB 'LENGT','H'+80H ; SET LENGTH
DW STBITS
DB 0 ;TABLE TERMINATOR
;
;
; "SET (no args): PRINT CURRENT STATISTICS
;
SETSHO: CALL MILP
DB CR,LF
DB 'SET values:',CR,LF,0
CALL CRLF
CALL BDSHOW
CALL CRLF
CALL SHPRTY
CALL CRLF
CALL SHSTOP
CALL CRLF
CALL SHBITS
CALL CRLF
CALL CRLF
RET
;
; "SET ?" processor
;
SETHELP: CALL MILP
DB CR,LF,'SET PARITY - OFF, EVEN or ODD'
DB CR,LF,'SET STOPBITS - 1, 1.5 or 2'
DB CR,LF,'SET LENGTH - 5, 6, 7 or 8'
DB CR,LF,'SET BAUD - 300, 450, 600, 1200, 2400, '
DB '4800, 9600, 19200'
DB CR,LF,CR,LF,0
RET
;
; "SET BAUD" processor
;
STBAUD: MVI C,BDPARS ;FUNCTION CODE: PARSE A BAUDRATE
CALL MEX ;LET MEX LOOK UP CODE
JC SETERR ;JUMP IF INVALID CODE
CALL PBAUD ;NO, TRY TO SET IT
JC SETERR ;IF NOT ONE OF OURS, BOMB OUT
BDSHOW: LDA MSPEED ;GET CURRENT BAUD RATE
MVI C,PRBAUD ;LET MEX PRINT IT
CALL MEX
RET
;
; This routine sets baud rate passed as MSPEED code in A.
; Returns CY=1 if baud rate not supported.
;
PBAUD: PUSH H ;DON'T ALTER ANYBODY
PUSH D
PUSH B
MOV E,A ;MSPEED CODE TO DE
MVI D,0
LXI H,BAUDTB ;OFFSET INTO TABLE
DAD D
MOV A,M ;FETCH CODE
ORA A ;0 MEANS UNSUPPORTED CODE
STC ;PREP CARRY IN CASE UNSUPPORTED
JZ PBEXIT ;EXIT IF BAD
PUSH PSW ;NO, SET THE RATE
MVI A,47H
OUT BAUDRP
POP PSW
OUT BAUDRP
MOV A,E ;GET MSPEED CODE BACK
STA MSPEED ;SET IT
ORA A ;RETURN NO ERRORS
PBEXIT: POP B
POP D
POP H
RET
;
BAUDTB: DB 0H ;110 (not supported)
DB 80H ;300
DB 55H ;450
DB 40H ;600
DB 0 ;710 (not supported)
DB 20H ;1200
DB 10H ;2400
DB 08H ;4800
DB 04H ;9600
DB 02H ;19200
;
; SET PARITY command: reset transmit/receive parity
;
; Parity is controlled by bits 0 and 1 of
; the byte sent to the SIO write-register
; 4 as follows:
;
; Parity Bit 1 Bit 0
; Off - 0
; Odd 0 1
; Even 1 1
;
STPRTY: MVI C,SBLANK ;check for parity code
CALL MEX ;
JC SETERR ;if none, print error
LXI D,PARTBL ;check for proper syntax
MVI C,LOOKUP
CALL MEX
PUSH H ;match found, go do it!
RNC ;
POP H ;no match: fix stack and
JMP SETERR ; print error
;
PROFF: LDA REG4 ;get register 4 byte
ANI 0FEH ;reset bit 0
JMP PARTB1 ;
PREVEN: LDA REG4 ;
ORI 003H ;set bits 0 & 1
JMP PARTB1 ;
PRODD: LDA REG4 ;
ORI 001H ;set bit 0
ANI 0FDH ;reset bit 1
PARTB1: STA REG4 ;
CALL NITSIO ;re-initialize the USART
CALL SHPRTY ;print the result
RET
;
SHPRTY: CALL MILP ;display parity
DB 'Parity: ',TAB,' ',0
LDA REG4 ;
ANI 001H ;test bit 0
CPI 0 ;if bit0=0 then parity off
JNZ SHPRT1 ;
CALL MILP ;
DB 'Off',0 ;
RET
SHPRT1: LDA REG4 ;
ANI 002H ;test bit 1
CPI 0 ;if bit1=0 then parity odd
JNZ SHPRT2 ;
CALL MILP ;
DB 'Odd',0 ;
RET ;
SHPRT2: CALL MILP ;
DB 'Even',0 ;
RET
;
; SET PARITY command table
;
PARTBL: DB 'OF','F'+80H ;"set parity off"
DW PROFF
DB 'EVE','N'+80H ;"set parity even"
DW PREVEN
DB 'OD','D'+80H ;"set parity odd"
DW PRODD
DB 0 ;<<== end of parity table
;
; SET STOPBITS command: reset number of stop bits
;
; The number of stop bits is controlled by bits
; 2 and 3 of the byte sent to the SIO write-
; register 4, as follows:
;
; Stop bits Bit 3 Bit 2
; 1 0 1
; 1.5 1 0
; 2 1 1
;
;
STSTOP: MVI C,SBLANK ;check for stop bits
CALL MEX ;
JC SETERR ;if none, print error
LXI D,STPTBL ;check for proper syntax
MVI C,LOOKUP
CALL MEX ;
PUSH H ;match found, go do it!
RNC ;
POP H ;no match: fix stack and
JMP SETERR ; print error
;
STOP01: LDA REG4 ;get register 4 byte
ANI 0F7H ;reset bit 3
ORI 004H ;set bit 2
JMP STSTP1 ;
STOP02: LDA REG4 ;
ORI 00CH ;set bits 2 and 3
JMP STSTP1 ;
STOP15: LDA REG4 ;
ORI 008H ;set bit 3
ANI 0FBH ;reset bit 2
STSTP1: STA REG4 ;
CALL NITSIO ;
CALL SHSTOP ;print the result
RET
SHSTOP: CALL MILP ;display stop-bits
DB 'Stop bits:',TAB,' ',0
LDA REG4 ;
ANI 004H ;test bit 2
CPI 0 ;if bit2=0 then 1.5
JNZ SHSTP1 ;
CALL MILP ;
DB '1.5',0 ;
RET
SHSTP1: LDA REG4 ;
ANI 008H ;test bit 3
CPI 0 ;if bit3=0 then 1
JNZ SHSTP2 ;
CALL MILP ;
DB '1',0 ;
RET
SHSTP2: CALL MILP ;
DB '2',0 ;
RET
;
; SET STOPBITS command table
;
STPTBL: DB '1'+80H ;"set stop 1"
DW STOP01
DB '2'+80H ;"set stop 2"
DW STOP02
DB '1.','5'+80H ;"set stop 1.5"
DW STOP15
DB 0 ;<<== End of stop-bits table
;
; SET LENGTH command: set bits per character
;
; The number of bits per character is controlled for
; the receiver circuit by bits 6 and 7 of the byte
; sent to the SIO write-register 3 and for the trans-
; mitter circuit by bits 5 and 6 of the byte sent to
; the SIO write-register 5. The assumption has been
; made here that both transmission and reception will
; be carried on at the same number of bits per charac-
; ter. The bit configurations are shown for register
; 3 only, but are the same for register 5:
;
; BPC Bit 7 Bit 6
; 5 0 0
; 6 1 0
; 7 0 1
; 8 1 1
;
STBITS: MVI C,SBLANK ;check for bits/char
CALL MEX ;
JC SETERR ;if none, print error
LXI D,BITTBL ;check for proper syntax
MVI C,LOOKUP
CALL MEX
PUSH H ;match found, go do it
!
RNC ;
POP H ;no match: fix stack and
JMP SETERR ; print error
;
BIT5: LDA REG3 ;
ANI 0BFH ;reset bit 6
ANI 07FH ;reset bit 7
STA REG3 ;
LDA REG5 ;
ANI 0DFH ;reset bit 5
ANI 0BFH ;reset bit 6
JMP STBTS1 ;
BIT6: LDA REG3 ;
ANI 0BFH ;reset bit 6
ORI 080H ;set bit 7
STA REG3 ;
LDA REG5 ;
ANI 0DFH ;reset bit 5
ORI 040H ;set bit 6
JMP STBTS1 ;
BIT7: LDA REG3 ;
ORI 040H ;set bit 6
ANI 07FH ;reset bit 7
STA REG3 ;
LDA REG5 ;
ORI 020H ;set bit 5
ANI 0BFH ;reset bit 6
JMP STBTS1 ;
BIT8: LDA REG3 ;
ORI 040H ;set bit 6
ORI 080H ;set bit 7
STA REG3 ;
LDA REG5 ;
ORI 020H ;set bit 5
ORI 040H ;set bit 6
STBTS1: STA REG5 ;
CALL NITSIO ;
CALL SHBITS ;print the result
RET
SHBITS: CALL MILP ;display bits/char
DB 'Bits/char:',TAB,' ',0
LDA REG5 ;
ANI 040H ;test bit 6
CPI 0 ;if bit6=0 then 6 bpc
JNZ SHBTS2 ;
LDA REG5 ;
ANI 020H ;test bit 5
CPI 0 ;if bit5=0 then 5 bpc
JNZ SHBTS1 ;
CALL MILP ;
DB '5',0 ;
RET ;
SHBTS1: CALL MILP ;
DB '7',0 ;
RET ;
SHBTS2: LDA REG5 ;
ANI 020H ;test bit 5
CPI 0 ;if bit5=0 then 6 bpc
JNZ SHBTS3 ;
CALL MILP ;
DB '6',0 ;
RET ;
SHBTS3: CALL MILP ;
DB '8',0 ;
RET
;
; SET LENGTH command table
;
BITTBL: DB '5'+80H ;"set bits 5"
DW BIT5
DB '6'+80H ;"set bits 6"
DW BIT6
DB '7'+80H ;"set bits 7"
DW BIT7
DB '8'+80H ;"set bits 8"
DW BIT8
DB 0 ;<<== end of bpc table
;
; General utility routines
;
MILP: MVI C,ILP ;IN-LINE PRINT
JMP MEX
RET
;
MTIME: MVI C,TIMER ;MEX TIMER
JMP MEX
RET
;
CRLF: CALL MILP ;PRINT CARRIAGE RETURN, LINE FEED
DB CR,LF,0
RET
;
;==========================================================================
; Data Area
;==========================================================================
;
; Default UART parameters (Initalized for External RS-232)
;
REG0: DB 00011000B ;RESET CHANNEL A
REG3: DB 11000001B ;ENABLE RECEIVE AT 8 BITS/CHAR
REG4: DB 01000100B ;NO PARITY, 1 STOP BIT, CLOCK X16
REG5: DB 11101010B ;ENABLE TRANSMIT AT 8 BITS/CHAR
;
; Miscellaneous Default Data
;
EOSMSG: DB 17H,'$' ;CLEAR TO END-OF-SCREEN
CLSMSG: DB 1AH,'$' ;CLEAR WHOLE SCREEN
;
END
