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Assembly Source File | 1980-01-01 | 40.9 KB | 1,126 lines

PAGE ,132 TITLE TTY - Radio Teletype Communications Program ; ; TTY is a program which allows the IBM Personal ; Computer to be used as a radio teletype terminal. ; ; This program runs under PC-DOS. ; The terminal unit must be connected to COM1. ; The terminal unit must activate the DATA SET READY ; status line to the COM1 port. ; ; See CQ magazine, November 1983, for an explanation of ; this program and how it works on the PC. ; ; Author: Jack Botner, VE3LNY ; BOTNER at TOROLAB ; Date: November 1983 ; Made available to IBMARC by VE3LNY. ; ; Operation: ; ; Type 'TTY' from DOS. Select the rtty code and baud rate. ; The program then enters receive mode. To transmit, press ; F5. To send your CWid at the end of a transmission, press ; F6. To return to receive, press F10. To select another ; rtty code/baud rate, or end the program, press F10 again. ; In receive using Murray code, if noise causes a false ; shift, use the F2 key to correct the shift state. ; ; Note that receive errors are common on RTTY, due to noise ; and interference on the signals. This program detects some ; of these errors as "framing" errors. The symbol corresponding ; to ascii code 15 (decimal) is displayed when one or more ; receive errors are detected. This symbol appears like a ; double asterisk and tells you that there are receive errors. ; ;***************************************************************** ; Use of this program is subject to the following conditions: ; 1. That it be distributed to and used by licenced amateur radio ; operators only; ; 2. That it be used for amateur radio purposes only; ; 3. Under no circumstances can this program be sold or otherwise ; used commercially or for profit; ; 4. That the origin and purpose of this program not be removed ; from this source code file. ;***************************************************************** ; ; Macro Definitions DISPLAY MACRO TEXT MOV DX,OFFSET TEXT MOV AH,9 ;Print String DOS function INT 21H ;call DOS ENDM ; LOCATE MACRO MOV AH,3 ;Read cursor posn BIOS function XOR BH,BH ;Page 0 INT 10H ;call BIOS ENDM ; SETCRS MACRO MOV AH,2 ;set cursor position BIOS function XOR BH,BH ;page 0 INT 10H ;call BIOS ENDM ; SCROLL MACRO MOV AH,6 ;Scroll up BIOS function XOR CX,CX ;begin row,col = 1,1 MOV DH,21 ;end row = 22 MOV DL,79 ;end col = 80 MOV BH,00000111B ;attribute byte INT 10H ;call BIOS ENDM ; ; Equates CR EQU 0DH LF EQU 0AH BEL EQU 0EH ;Bell symbol (display) ERR EQU 0FH ;Error symbol for display ; STACK SEGMENT PARA STACK 'STACK' DB 64 DUP ('STACK ') STACK ENDS ; SUBTTL TTY Data and Workarea Definitions ; DATA SEGMENT PARA PUBLIC 'DATA' CWID DB 'DE URCALL$' ;Your call here for CWid ; ; Communications Parameters Tables for 8250 COM1. ; Table entries correspond to fkey descriptions ; for Fkeys: F1 F2 F3 DLABM DB 00AH,06H,04H ;Divisor Latch most significant byte DLABL DB 000H,14H,17H ;Divisor latch least significant byte LCR DB 004H,04H,3EH ;Line control reg. (bits, parity, etc.) RCODE DB 001H,01H,02H ;1=murray (baudot), 2=ascii code REQUEST DB 0 ;Which Fkey was selected ; ; Main selection panel PANEL1 DB 'Teletype Terminal Program',CR,LF,CR,LF,CR,LF DB 'F1: Murray 45 baud, 5 data bits, 2 stop bits, parity N' DB CR,LF,CR,LF DB 'F2: Murray 74 baud, 5 data bits, 2 stop bits, parity N' DB CR,LF,CR,LF DB 'F3: Ascii 110 baud, 7 data bits, 2 stop bits, parity S' DB CR,LF,CR,LF DB 'F10: END Program$' ; LIN25 DB 'F2=SHIFT F5=XMIT F6=CWID F10=END$' ERR1 DB CR,LF,'No communications adapter address in system.' DB CR,LF,'$' ERR2 DB CR,LF,'Time-out error on communications adapter.' DB ' Check your modem/TU',CR,LF,'$' ERR3 DB CR,LF,'Your display must be configured for 80 column' DB ' width.',CR,LF,'$' ERR4 DB 'and press any key to retry (Esc key to end).' DB CR,LF,'$' ; RMSG DB 'Receiving...$' TMSG DB 'Transmitting...$' ; ; Tables for converting Murray to Ascii & back LTRTAB DB 0,'E',LF,'A SIU',CR,'DRJNFCKTZLWHYPQOBG MXV ' FIGTAB DB 0,'3',LF,'- ',BEL,'87',CR,'$4',27H,',!:(5',22H DB ')2#6019?& ./; ' ; ; bit 0: 0 = char defined, 1 = char not defined ; bit 1: 0 = LTRS, 1 = FIGS ; bit 2: 1 = same code for either shift ; bits 3-7: Murray code for character ; LF MURRAY DB 10 DUP(80H),22H,80H,80H ; CR SP ! " # $ % & DB 28H,18 DUP(80H),24H,4DH,51H,54H,49H,80H,5AH ; ' ( ) * + , - . / 0 1 2 3 4 DB 4BH,4FH,52H,80H,80H,4CH,43H,5CH,5DH,56H,57H,53H,41H,4AH ; 5 6 7 8 9 : ; < = > ? @ A B DB 50H,55H,47H,46H,58H,4EH,5EH,80H,80H,80H,59H,80H,03H,19H ; C D E F G H I J K L M N O P DB 0EH,09H,01H,0DH,1AH,14H,06H,0BH,0FH,12H,1CH,0CH,18H,16H ; Q R S T U V W X Y Z ╒\σ^_ ' DB 17H,0AH,05H,10H,07H,1EH,13H,1DH,15H,11H,5 DUP(80H),4BH ; a b c d e f g h i j k l m n DB 03H,19H,0EH,09H,01H,0DH,1AH,14H,06H,0BH,0FH,12H,1CH,0CH ; o p q r s t u v w x y z {]}~ DB 18H,16H,17H,0AH,05H,10H,07H,1EH,13H,1DH,15H,11H,5 DUP(80H) ; LCRAD DW ? ;8250 LCR address ; CW Speed Factor - larger number SPEED DW 16000 ; means slower CW speed CWIDPTR DW ? ; ; Table for generating CWid. ; Each hex byte 'ab' in the table represents the following: ; 1. Turn the Break bit on in the comm adapter ; 2. Wait 'a' units of time ; 3. Turn the Break bit off in the comm adapter ; 4. Wait 'b' units of time. ; When 'b' equals 2, the character is complete. TABLE DB 'A',11H,32H,00H,00H,00H,00H DB 'B',31H,11H,11H,12H,00H,00H DB 'C',31H,11H,31H,12H,00H,00H DB 'D',31H,11H,12H,00H,00H,00H DB 'E',12H,00H,00H,00H,00H,00H DB 'F',11H,11H,31H,12H,00H,00H DB 'G',31H,31H,12H,00H,00H,00H DB 'H',11H,11H,11H,12H,00H,00H DB 'I',11H,12H,00H,00H,00H,00H DB 'J',11H,31H,31H,32H,00H,00H DB 'K',31H,11H,32H,00H,00H,00H DB 'L',11H,31H,11H,12H,00H,00H DB 'M',31H,32H,00H,00H,00H,00H DB 'N',31H,12H,00H,00H,00H,00H DB 'O',31H,31H,32H,00H,00H,00H DB 'P',11H,31H,31H,12H,00H,00H DB 'Q',31H,31H,11H,32H,00H,00H DB 'R',11H,31H,12H,00H,00H,00H DB 'S',11H,11H,12H,00H,00H,00H DB 'T',32H,00H,00H,00H,00H,00H DB 'U',11H,11H,32H,00H,00H,00H DB 'V',11H,11H,11H,32H,00H,00H DB 'W',11H,31H,32H,00H,00H,00H DB 'X',31H,11H,11H,32H,00H,00H DB 'Y',31H,11H,31H,32H,00H,00H DB 'Z',31H,31H,11H,12H,00H,00H DB '1',11H,31H,31H,31H,32H,00H DB '2',11H,11H,31H,31H,32H,00H DB '3',11H,11H,11H,31H,32H,00H DB '4',11H,11H,11H,11H,32H,00H DB '5',11H,11H,11H,11H,12H,00H DB '6',31H,11H,11H,11H,12H,00H DB '7',31H,31H,11H,11H,12H,00H DB '8',31H,31H,31H,11H,12H,00H DB '9',31H,31H,31H,31H,12H,00H DB '0',31H,31H,31H,31H,32H,00H DB '.',11H,31H,11H,31H,11H,32H DB ',',31H,31H,11H,11H,31H,32H DB '-',31H,11H,11H,11H,32H,00H DB '?',11H,11H,31H,31H,11H,12H DB '/',31H,11H,11H,31H,12H,00H DB 0FFH ;Mark end of table ; SW1 DB 0 ;Program switches SHON EQU 10000000B ;Shift state = FIGS TRON EQU 01000000B ;In transmit state AERRON EQU 00100000B ;Ascii error flag OVRUN EQU 00010000B ;Overrun error occurred bit FERON EQU 00001000B ;Last char had framing error bit ASCII EQU 00000001B ;0=Murray, 1=ASCII ; SW2 DB 0 CRON EQU 10000000B ;Last char was CR LFON EQU 01000000B ;Last char was LF DATA ENDS ; SUBTTL TTY Code Segment: Mainline ; CODE SEGMENT PARA PUBLIC 'CODE' ASSUME CS:CODE,DS:DATA,SS:STACK TTY PROC FAR PUSH DS ;Establish conditions for XOR AX,AX ; FAR return to DOS at PUSH AX ; end of program. MOV AX,DATA MOV DS,AX MOV ES,AX ;ES=DS JMP START ; ; COM1 receive interrupt routine workarea COMADDR DW ? ;8250 Async Adapter Address ADBUF DB 32 DUP (?) ;Receive buffer: data ERBUF DB 32 DUP (?) ;Receive buffer: status codes INPTR DB 0 ;Insert byte count OUTPTR DB 0 ;Extract byte count ADLEN DB 32 ;Buffer length ADCNT DB 0 ;Byte count ; START: CLD ; Make sure display configured for 80 columns MOV AH,15 ;Current video state BIOS function INT 10H ;call BIOS CMP AH,80 ;Width = 80? JE IA100 DISPLAY ERR3 ;Invalid display config. JMP PGMEXIT ; ; The ACA address is taken from the first COM adapter addresses ; in the ROM BIOS Data Area, located at segment address 40H. ; The COM adapter address is extracted, and validated to make ; sure the adapter is actually installed. IA100: PUSH ES MOV AX,40H MOV ES,AX ;ROM BIOS Data Area Segment MOV AX,WORD PTR ES:0 ;Get RS232 Base Address POP ES CMP AX,0 JNE IA300 DISPLAY ERR1 ;Invalid adapter specification JMP PGMEXIT ; IA300: MOV COMADDR,AX ;Save RS232 Adapter Address ; ; Initialize Communications Environment ; ; Initialize Modem Control Register with DTR flag MOV DX,COMADDR ;Reload adapter address ADD DX,4 ;Address Modem Control Register (3FC) MOV AL,00000001B ;Turn DTR flag on, all others off OUT DX,AL ;Write MCR register ; ; Receive Modem Status Register from adapter IA500: MOV CX,22 ;Establish time-out count MOV DX,COMADDR ;Reload adapter address ADD DX,6 ;Modem Status Register Address (3FE) ; IC100: IN AL,DX ;Read Modem Status Register TEST AL,00100000B ;Test Data Set Ready flag JZ IC300 ;DSR off - process error JMP IE100 ;DSR is on - continue ; IC300: CALL PAUSE ;Retry CX times before giving up, LOOP IC100 ; waiting PAUSE between retries ; ; Process time-out error by giving user chance to try again DISPLAY ERR2 ;State error DISPLAY ERR4 ;State action ; Get response MOV AH,0CH ;Clr kybd DOS req MOV AL,7 ;Then direct console input req INT 21H ;Call DOS CMP AL,0 ;Returned keystroke JNE ID100 ;Not extended ASCII ; Discard extended ascii code MOV AH,7 ;Direct console input req INT 21H ;Call DOS JMP IA500 ;Retry test for DSR ; ID100: CMP AL,27 ;ESCape key? JE ID300 JMP IA500 ;Retry test for DSR ID300: JMP PGMEXIT ;That's all, folks ; ; Establish 0C interrupt handling routine vector. IE100: PUSH DS MOV AH,25H ;Set Interrupt Vector DOS function MOV AL,0CH ;Interrupt type MOV CX,CS MOV DS,CX MOV DX,OFFSET INT0C ;ENTRY_0C INT 21H ;Call DOS POP DS ; ; Enable IRQ4 interrupt on 8259 interrupt controller IN AL,21H ;Read IMR AND AL,11101111B ;Turn off IRQ4 bit to enable interrupt OUT 21H,AL ;Write OCW1 (IMR) ; ; Enter here to re-set communications parameters ; ; Display TTY Initial Selection Panel INITIALIZE: CALL CLEAR ;Clear the screen MOV DH,3 ;Row=4 XOR DL,DL ;Col=1 SETCRS ;Set cursor address to locate panel ; DISPLAY PANEL1 ;Display selection panel ; IG100: MOV AH,8 ;Console input DOS req INT 21H ;Call DOS CMP AL,0 ;0=extended ascii code returned JZ IG300 ;Look for F1-F10 JMP IG100 ;Pressed wrong key ; IG300: MOV AH,8 ;Console input DOS req INT 21H ;Call DOS CMP AL,59 ;F1 JE IG500 CMP AL,60 ;F2 JE IG500 CMP AL,61 ;F3 JE IG500 CMP AL,68 ;F10 JE IG500 JMP IG100 ; IG500: PUSH AX CALL CLEAR ;Clear the screen XOR DX,DX ;Row 1, col 1 SETCRS ;Set cursor position POP AX ; CMP AL,68 ;F10? JNE IH100 ;No, select baud etc. JMP END_RUN ;Run complete ; IH100: SUB AL,58 ;Make number relative to 0 MOV REQUEST,AL ;Save fkey number SUB BX,BX MOV BL,AL ;Create index register for DEC BX ; table lookup ; ; Write 1 into Divisor Latch Access Bit of Line Control Register ; to allow access to Divisor Latches (Baud Rate Generator). MOV DX,COMADDR ;Load adapter address ADD DX,3 ;Point to 8250 control register (3FB) MOV AL,80H OUT DX,AL ;Set DLAB=1 (divisor latch access bit) ; ; Write high-order byte of baud rate divisor to Divisor Latch MOV DX,COMADDR ;Reload adapter address INC DX ;Divisor Latch Most Sig. Bits (3F9) MOV AL,DLABM╒BXσ ;Baud rate OUT DX,AL ;Set baud rate Most Significant Bits ; ; Write low-order byte of baud rate divisor to Divisor Latch DEC DX ;Divisor Latch Least Sig. Bits (3F8) MOV AL,DLABL╒BXσ ;Baud rate OUT DX,AL ;Set Baud Rate Least Significant bits ; ; Write Line Control Register to set Data Bits, Stop Bits, Parity, ; and reset Divisor Latch Access Bit. ADD DX,3 ;Point to 8250 control reg. (3FB) MOV AL,LCR╒BXσ ;Set Parity, Stop Bits, Word Lenth OUT DX,AL ;Send Line Control Register Data ; ; Write Interrupt Enable Register to enable 8250 interrupt. ; Update Modem Control Register to enable interrupts CALL ENAINT ;Enable interrupt for receive ; ; Get code selection and build info lines AND SW1,0FFH-ASCII ;Indicate Murray mode MOV AL,RCODE╒BXσ CMP AL,02 JNE II100 OR SW1,ASCII ;Indicate ASCII mode ; ; Display Fkey description line 25 II100: MOV DH,24 ;Row 25 XOR DL,DL ;Col 1 SETCRS DISPLAY LIN25 ; XOR DX,DX ;Row,col = 1,1 SETCRS AND SW1,0FFH-TRON-SHON-FERON ; ; Scan keyboard for requests ; READ_KEYBD: MOV AH,0BH ;Check Keyboard Status DOS code INT 21H ;Invoke DOS CMP AL,0 ;00=no character available JNE MA100 JMP MF400 ; MA100: MOV AH,8 ;Keyboard Input DOS code INT 21H ;Call DOS CMP AL,0 ;If AL=0 then char is extended ASCII code JE MB100 ;Go read second character TEST SW1,TRON ;If receive mode, ignore character typed JZ MA500 ; on keyboard and go poll adapter JMP SEND_ADAPTER MA500: JMP READ_ADAPTER ; ; Process Extended ASCII code for function key requests. MB100: MOV AH,8 ;Keyboard Input again INT 21H ;Invoke DOS CMP AL,59 JB MB500 ;Check for F1-F10 range CMP AL,68 JNA MC300 ; MB500: TEST SW1,TRON JNZ MC100 ;In receive mode, go scan ACA JMP READ_ADAPTER ; for received character. MC100: JMP READ_KEYBD ; MC300: SUB AL,58 ;F1-F10 selected. ; CMP AL,2 ;Check for F2 key (Toggle Shift) JNE MD300 TEST SW1,ASCII ;Does not apply to ASCII mode JNZ MC500 TEST SW1,TRON ;Allow in receive mode only JZ MC700 MC500: JMP MF200 ;Sound alarm and continue ; MC700: TEST SW1,SHON ;Process toggle shift JZ MD100 AND SW1,0FFH-SHON ;Turn the switch off JMP MF400 MD100: OR SW1,SHON ;Turn the switch on JMP MF400 ; MD300: CMP AL,5 ;Check for F5 key (transmit request) JNE ME100 TEST SW1,TRON ;Allow in receive mode only JZ MD500 JMP MF200 ;Sound alarm and continue ; MD500: AND SW1,0FFH-SHON ;Reset to LTRS shift OR SW1,TRON ;Set transmit mode MOV DX,OFFSET TMSG CALL DISPLAY_MESSAGE CALL DISINT ;Disable 8250 adapter interrupts ; CALL RTSON ;Turn on request-to-send signal JMP MF400 ; ME100: CMP AL,6 ;Check for F6 key (send CW ID) JNE ME400 TEST SW1,TRON JNZ ME300 ;Invalid request if in receive mode JMP MF200 ;Sound alarm and continue ; ME300: CALL CWID_RTN ;send CW ID JMP MF400 ;OK ; ME400: CMP AL,10 ;Check for F10 key (END) JE ME500 JMP MF200 ;Go sound alarm for bad Fkey ; ME500: TEST SW1,TRON ;In transmit mode? JNZ ME700 JMP MF100 ; ME700: AND SW1,0FFH-TRON ;Return to receive mode here MOV DX,OFFSET RMSG CALL DISPLAY_MESSAGE ; CALL ENAINT ;Enable 8250 adapter interrupts CALL RTSOFF ;Turn off request-to-send signal JMP MF400 ;Done with this request ; MF100: CALL DISINT ;Disable 8250 adapter interrupts CALL RTSOFF ;Turn off request-to-send signal JMP INITIALIZE ;Return to main menu ; MF200 LABEL NEAR CALL ALARM ;Error or undefined key selected ; MF400: TEST SW1,TRON ;End of F1-F10 processing JNZ MG100 JMP READ_ADAPTER ;In receive, continue scanning adapter MG100: JMP READ_KEYBD ; ; Communicatiins Adapter SEND routine ; SEND_ADAPTER: ;Char from keyboard in AL SUB AH,AH AND AL,01111111B ;Make sure high order bit is zero. TEST SW1,ASCII JZ MH100 MOV DL,AL ;ASCII: use character as entered JMP MH200 ; MH100: MOV SI,AX ;Murray: translate required MOV DL,MURRAY╒SIσ ;Get Murray equivalent of ASCII TEST DL,10000000B ;Test for invalid character JZ MH200 CALL ALARM ;Sound the alarm JMP MJ500 ;Bypass invalid character ; MH200: PUSH DX MOV DL,AL CALL DISPLAY_CHAR POP DX ; TEST SW1,ASCII ;Bypass shift jazz for ASCII JZ MH400 JMP MI200 MH400: TEST DL,00100000B ;Test shift irrelevant bit JNZ MI100 TEST DL,01000000B ;Test for shift JZ MH600 ; Char to send is FIGS TEST SW1,SHON ;What was sent last? JNZ MI100 MOV AL,1BH ;1B = FIGS CALL XMIT_CHAR OR SW1,SHON ;Indicate in FIGS shift now JMP MI100 ; MH600: TEST SW1,SHON ;char to send is LTRS JZ MI100 MOV AL,1FH ;1F = LTRS CALL XMIT_CHAR AND SW1,0FFH-SHON ;Indicate in LTRS shift now ; MI100: AND DL,00011111B ; Write char in DL to async adapter MI200: MOV AL,DL ;Char to send CALL XMIT_CHAR ; TEST SW1,ASCII ;Bypass shift jazz for ASCII JNZ MI500 CMP DL,8 ;If a CR was sent (Murray 08H), JE MI400 ; then a LF must also be sent JMP MJ500 ; MI400: MOV DL,2 ;LF = Murray 02H JMP MJ300 ; MI500: CMP DL,CR ;If CR was sent (ASCII), JE MJ100 ; then a LF must also be sent JMP MJ500 ; MJ100: MOV DL,LF ; Write character in DL to ACA MJ300: MOV AL,DL ;Char to send CALL XMIT_CHAR MOV DL,LF ;Send to display too CALL DISPLAY_CHAR MJ500: JMP READ_KEYBD ; ; Communications Adapter READ routine ; READ_ADAPTER: CMP ADCNT,0 ;See if anything is in the buffer JA MK100 JMP READ_KEYBD ;Buffer is empty - continue elsewhere ; ; The following statuses (of interest) are possible in ERBUF: ; Bit 3 = FRAMING ERROR Bit 1 = OVERRUN ERROR MK100: CLI ;no interrupts SUB BH,BH MOV BL,OUTPTR MOV AH,ERBUF╒BXσ ;load status byte MOV AL,ADBUF╒BXσ ;load data byte INC BL CMP BL,ADLEN ;perform maintenance on buffer pointer JB MK300 SUB BL,BL MK300: MOV OUTPTR,BL DEC ADCNT STI ;Interrupts OK now ; TEST AH,00000010B ;Overrun error? JZ MK500 OR SW1,OVRUN ;Indicate overrun error occurred JMP READ_ADAPTER ;throw away byte ; MK500: TEST AH,00001000B ;Framing error? JZ ML200 TEST SW1,FERON ;Was the last character in error too? JZ ML100 JMP READ_ADAPTER ;Yes, ignore this character (gibberish) ; ML100: OR SW1,FERON ;No, turn on error indicator MOV DL,ERR ;Indicate error occurred JMP MM700 ; ML200: AND SW1,0FFH-FERON ;RESET error switch TEST SW1,ASCII ;don't translate ASCII, of course JZ ML700 ; ; Validate ASCII character MOV DL,AL ;check ASCII for obvious errors CMP DL,1FH JA ML500 CMP DL,CR ;DL is less than 20H, which might be bad JE ML500 CMP DL,LF JE ML500 TEST SW1,AERRON ;was last character in error too? JZ ML400 JMP READ_ADAPTER ML400: MOV DL,ERR ;substitute error code OR SW1,AERRON JMP MM700 ML500: AND SW1,0FFH-AERRON JMP MM500 ; ; Translate MURRAY code to ASCII ML700: SUB AH,AH ;AL contains Murray character AND AL,00011111B ;Make sure high 3 bits are off MOV BX,AX ; and use as base register CMP AL,1BH ;FIGS character? JNE MM100 OR SW1,SHON ;Set status to FIGS JMP READ_ADAPTER ;Go read another character ; MM100: CMP AL,1FH ;LTRS character? JNE MM200 AND SW1,0FFH-SHON ;Set status to LTRS JMP READ_ADAPTER ;Go read another character ; MM200: TEST SW1,SHON ;Is it FIGS? JZ MM400 ; Translate FIGS character MOV DL,FIGTAB╒BXσ JMP MM500 ; Translate LTRS character MM400: MOV DL,LTRTAB╒BXσ ; MM500: CMP DL,0 ;BLANK char? JNE MM700 JMP READ_ADAPTER ;BLANK=no print or carriage movement ; MM700: CALL DISPLAY_CHAR JMP READ_KEYBD ; SUBTTL Restore Communications Environment END_RUN: ; ; Disable Interrupt Enable Register flag CALL DISINT ; ; Disable IRQ4 interrupt on 8259 interrupt controller IN AL,21H ;Read IMR OR AL,00010000B ;turn on IRQ4 bit to disable interrupt OUT 21H,AL ;Write OCW1 (IMR) ; ; Clear 0C interrupt handling routine vector. PUSH DS MOV AH,25H ;Set Interrupt Vector DOS function MOV AL,0CH ;Interrupt type XOR DX,DX ;clear address MOV DS,DX INT 21H ;call DOS POP DS ; ; Write Modem Control Register to clear flags MOV DX,COMADDR ;Load adapter address ADD DX,4 ;Address modem control register (3FC) MOV AL,0 ;All flags clear OUT DX,AL ;Write MCR register ; CALL CLEAR ;Clear the screen MOV AH,2 ;Set cursor position BIOS function XOR DX,DX ;Row,col = 1,1 XOR BH,BH ;Page 0 INT 10H ;Call BIOS ; PGMEXIT: RET ;Return to DOS TTY ENDP ; ; Display character in DL routine ; DISPLAY_CHAR PROC NEAR PUSH AX PUSH BX PUSH CX CMP DL,CR JNE SA200 OR SW2,CRON ;Process carrier return LOCATE ; DH = Row, DL = column of cursor position XOR DL,DL ;Column = 1 SETCRS ;Set cursor position JMP SA900 ; SA200: CMP DL,LF JNE SA400 OR SW2,LFON ;Process line feed LOCATE ; DH = Row, DL = column of cursor position INC DH ;Next row CMP DH,21 ;Past row 22? JNA SA300 ; PUSH DX MOV AL,1 ;Scroll 1 line SCROLL POP DX MOV DH,21 ;Row = 22 ; SA300: SETCRS ;Set cursor position JMP SA900 ; SA400: TEST SW2,CRON ;Process the character JZ SA600 TEST SW2,LFON ;If preceding CR not accompanied by JNZ SA600 ; LF, corrective action is necessary ; LOCATE ; DH = Row, DL = column of cursor position INC DH ;Next row CMP DH,21 ;Past row 22? JNA SA500 ; PUSH DX MOV AL,1 ;Scroll 1 line SCROLL POP DX MOV DH,21 ;Row = 22 ; SA500: SETCRS ;Set cursor position ; SA600: MOV AH,9 ;Write char BIOS function XOR BH,BH ;Page = 0 MOV CX,1 ;Number of characters MOV AL,DL ;Character MOV BL,00000111B ;Attribute byte INT 10H ;Call BIOS AND SW2,0FFH-CRON-LFON ; LOCATE ;Read cursor position ; DH = Row, DL = column of cursor position INC DL ;Next column CMP DL,79 ;Past end of row? JNA SA700 ; XOR DL,DL ;Reset to column 1 INC DH ;Next row CMP DH,21 ;Past row 22? JNA SA700 ; MOV AL,1 ;Scroll 1 line SCROLL MOV DH,21 ;Set cursor to row 22 MOV DL,0 ;Set cursor to column 1 ; SA700: SETCRS ;Set cursor position ; SA900: POP CX POP BX POP AX RET DISPLAY_CHAR ENDP ; ; Display a Message routine ; DISPLAY_MESSAGE PROC NEAR PUSH AX PUSH BX PUSH CX PUSH DX LOCATE ;Read cursor position ; DH = Row, DL = column of cursor position ADD DH,2 ;Add 2 giving target row CMP DH,21 ;Compare with line 22 JA SC100 JB SC300 ;No scroll required MOV AL,1 ;Scroll 1 line only JMP SC200 ; SC100: MOV AL,2 ;Scroll 2 lines ; SC200: SCROLL ;Scroll up AL lines ; MOV DH,21 ;Set cursor to row 22 ; SC300: MOV DL,0 ;Set cursor to column 1 SETCRS ;Set cursor position ; POP DX ;Restore message offset MOV AH,9 ;Print String DOS function INT 21H ;Call DOS ; LOCATE ;Read cursor position ; ADD DH,2 ;Add 2 giving target row CMP DH,21 ;Compare with line 22 JA SC400 JB SC600 ;No scroll required MOV AL,1 ;Scroll 1 line only JMP SC500 ; SC400: MOV AL,2 ;Scroll 2 lines ; SC500: SCROLL ;Scroll up AL lines MOV DH,21 ;set cursor to row 22 ; SC600: MOV DL,0 ;column = 1 SETCRS ;set cursor position ; SC900: POP CX POP BX POP AX RET DISPLAY_MESSAGE ENDP ; ; Send CWID Routine ; CWID_RTN PROC NEAR PUSH BX PUSH CX PUSH DX PUSH SI CLD ; MOV DX,COMADDR ;Point to 8250 Line Control register ADD DX,3 MOV LCRAD,DX ;Save LCR address IN AL,DX ;Read current setting of LCR TEST AL,01000000B ;Is set break bit on? JZ SF100 AND AL,10111111B ;If break bit is on, turn it off OUT DX,AL ; and send it back to the adapter ; SF100: MOV AL,10 CALL CWID_PAUSE ;Pause before sending ID MOV AX,OFFSET CWID MOV CWIDPTR,AX ; SF200: MOV SI,CWIDPTR MOV AL,BYTE PTR ╒SIσ CMP AL,'$' ;End of message? JNE SF300 JMP SG800 ;All done ; SF300: CMP AL,' ' ;Space? JNE SF500 ; SF400: MOV AL,2 CALL CWID_PAUSE ;Pause between words JMP SG500 ; SF500: MOV BX,OFFSET TABLE ; Search for character in table SF600: MOV AH,BYTE PTR ╒BXσ CMP AH,0FFH ;End of the table? JNE SG100 JMP SF400 ;Letter not found in table ; SG100: CMP AL,AH ;Is this the entry we want? JE SG200 ADD BX,7 ;Try next entry in table JMP SF600 ; SG200: INC BX MOV AL,BYTE PTR ╒BXσ MOV AH,AL MOV CL,4 SHR AH,CL ;Extract high-order digit AND AL,0FH ;Extract low-order digit ; MOV CX,AX MOV DX,LCRAD IN AL,DX ;Read current setting of LCR OR AL,01000000B ;Turn the break bit on OUT DX,AL ;Send new LCR register contents MOV AL,CH ;Table byte (value = 1, 2 or 3) CALL CWID_PAUSE ; IN AL,DX ;Read current setting of LCR AND AL,10111111B ;Turn the break bit off OUT DX,AL ;Send new LCR register contents MOV AL,CL ;Table byte (value = 1, 2 or 3) CALL CWID_PAUSE ; CMP CL,2 ;2 = character complete JE SG500 JMP SG200 ;Process next segment of character ; SG500: INC CWIDPTR ;On to next character JMP SF200 ; SG800: POP SI POP DX POP CX POP BX RET CWID_RTN ENDP ; CWID_PAUSE PROC NEAR ;relative delay in AL (1-8) PUSH CX CMP AL,2 ;2 means end-of-character JNE SJ100 MOV AL,3 ;Wait 3 after character complete too ; SJ100: MOV CX,SPEED SJ200: LOOP SJ200 ;Wait awhile DEC AL OR AL,AL ;Test for zero JNZ SJ100 POP CX RET CWID_PAUSE ENDP ; SUBTTL Enable interrupt on 8250 communications adapter ; ENAINT PROC NEAR ; ; Write Interrupt Enable Register to enable 8250 interrupt. MOV DX,COMADDR ;Reload adapter address INC DX ;Address Interrupt Enable Reg. (3F9) MOV AL,1 ;Enable Data Available Interrupt OUT DX,AL ;Send Interrupt Enable Register Data ; ; Update Modem Control Register to enable interrupts ADD DX,3 ;Address modem control register (3FC) IN AL,DX ;Present MCR contents OR AL,00001000B ;Turn ON OUT2 flag OUT DX,AL ;rewrite MCR register ; ; If an interrupt is pending, the 8250 does not honor the enable ; until it is cleared. SUB DX,2 ;Interrupt ID. Reg. (3FA) IN AL,DX ;read Interrupt ID port TEST AL,00000001B ;0 if interrupt pending JNZ SM900 SUB DX,2 ;Receiver Buffer Reg. (3F8) IN AL,DX ;clear pending interrupt - discard byte SM900: RET ENAINT ENDP ; SUBTTL Disable interrupts on 8250 communications adapter ; DISINT PROC NEAR ; ; Write Interrupt Enable Register to disable 8250 interrupt. MOV DX,COMADDR ;Reload adapter address INC DX ;Point to Interrupt Enable Register (3F9 MOV AL,0 ;Disable all interrupts OUT DX,AL ;Send Interrupt Enable Register Data ; ; Update Modem Control Register to disable interrupts ADD DX,3 ;Point to modem control register (3FC) IN AL,DX ;Present MCR contents AND AL,11110111B ;Turn OUT2 OFF OUT DX,AL ;Rewrite MCR register RET DISINT ENDP ; SUBTTL Turn ON/OFF Request to Send signal ; RTSON PROC NEAR ; ; Update Modem Control Register to turn on RTS flag MOV DX,COMADDR ;Comm Adapter Address ADD DX,4 ;point to modem control register (3FC) IN AL,DX ;get current contents of register OR AL,00000010B ;Turn bit 1 ON (RTS line) OUT DX,AL ;rewrite MCR register RET RTSON ENDP ; RTSOFF PROC NEAR ; ; Update Modem Control Register to turn off RTS flag MOV DX,COMADDR ;Comm Adapter Address ADD DX,4 ;point to modem control register (3FC) IN AL,DX ;get current contents of register AND AL,11111101B ;Turn bit 1 OFF (RTS line) OUT DX,AL ;Rewrite MCR register RET RTSOFF ENDP ; ; Send character in AL XMIT_CHAR PROC NEAR PUSH DX PUSH AX ;Save input character ; XM200: MOV DX,COMADDR ;Load adapter address ADD DX,5 ;Adress of Line Status Reg. (3FD) IN AL,DX ;Read LSR TEST AL,00100000B ;Test TX hold register empty? JNZ XM400 ;Ready to accept data JMP XM200 ;Not ready so try again ; XM400: MOV DX,COMADDR ;Load adapter address THR (3F8) POP AX ;Restore character OUT DX,AL ;Write to THR POP DX RET XMIT_CHAR ENDP ; PAUSE PROC NEAR ;PAUSE routine PUSH CX XOR CX,CX SP100: LOOP SP100 POP CX RET PAUSE ENDP ; CLEAR PROC NEAR ;CLEAR SCREEN Routine MOV AH,6 ;Scroll up BIOS function MOV AL,0 ;Clear screen request XOR CX,CX ;Start row,col = 1,1 MOV DH,24 ;End row = 25 MOV DL,79 ;End col = 80 MOV BH,00000111B ;Attribute byte INT 10H ;Call BIOS ; RET CLEAR ENDP ; SUBTTL ALARM - Sound the ALARM ; TIMER EQU 40H PORT_B EQU 61H ;8255 port B addr ; ALARM PROC NEAR PUSH CX CLD MOV AL,10110110B ;SEL TIM 2, LSB,MSB,Binary OUT TIMER+3,AL ;Write the Timer Mode Reg MOV AX,400H OUT TIMER+2,AL ;Write Timer 2 cnt - LSB MOV AL,AH OUT TIMER+2,AL ;Write Timer 2 cnt - MSB IN AL,PORT_B ;Get current setting of port MOV AH,AL ;Save the setting OR AL,03 ;Turn speaker on OUT PORT_B,AL SUB CL,CL ;Set cnt to wait awhile MOV CH,64 ST100: LOOP ST100 ;Delay before turning off MOV AL,AH ;Recover value of port OUT PORT_B,AL POP CX RET ALARM ENDP ; SUBTTL TTYINTR - Adapter Interrupt 0C Routine ; INT0C PROC FAR STI ;Enable interrupts PUSH AX PUSH BX PUSH CX PUSH DX PUSH SI PUSH DI CLD ; SW100: MOV DX,COMADDR ;Load adapter address ADD DX,5 ;Address the Line Status Register (3FD) IN AL,DX ;Read Line Status Register TEST AL,01H ;Test Data Ready bit JNZ SW300 ;One means data is available in receive JMP SW900 ;No data, so quit ; ; The following statuses (of interest) are possible in AL: ; Bit 3 = FRAMING ERROR Bit 1 = OVERRUN ERROR SW300: MOV CL,AL ;Save status byte in CL MOV DX,COMADDR ;Get Receive Buffer Register addr (3F8) IN AL,DX ;Read one byte from adapter MOV CH,AL ;Save data byte in CH ; SUB BH,BH MOV BL,INPTR MOV ADBUF╒BXσ,CH ;Store data byte in buffer MOV ERBUF╒BXσ,CL ;Store status byte in buffer ; INC BL ;Point to next byte in buffers CMP BL,ADLEN ;Check for wrap-around in buffer JB SW500 SUB BL,BL ;Reset pointer at wrap-around SW500: MOV INPTR,BL ;Update pointer MOV CL,ADCNT INC CL ;Increment active byte count CMP CL,ADLEN ;Check for buffer overrun JNA SW700 MOV CL,1 ;Throw away buffer contents when overrun SW700: MOV ADCNT,CL ; SW900: CLI ;Disable interrupts MOV AL,20H ;Signal end of interrupt to OUT 20H,AL ; 8259 via OCW2 register POP DI POP SI POP DX POP CX POP BX POP AX IRET INT0C ENDP ; CODE ENDS END TTY