Internet Info 1994 March

home *** CD-ROM | disk | FTP | other *** search

/ Internet Info 1994 March / Internet Info CD-ROM (Walnut Creek) (March 1994).iso / networking / terms / kermit / a / msxtip.asm < prev next >

Wrap

Assembly Source File | 1988-08-15 | 39.9 KB | 932 lines

name msxtip ; File MSXTIP.ASM ; Last modification: 20 April 1986 revlvl equ 6 ; Rev level 6, 13 April 1986 ;;;REVLVL EQU 5 ;Revision level 6-25-85 ;============================================================================== ; ; MSXTIPRO.ASM This file contains system dependent routines for the ; TI-Professional computer running MS-DOS version 2.10. This ; version features interrupt driven I/O and H19/Tektronix 4010 ; emulation. This version has been tested at 9600 baud with ; no loss of data. ; ; Credits: Dan Smith Computing Center (303) 273-3396 ; Colorado School of Mines ; Golden, Colorado 80241 ; Joe Smith (now at TYMSHARE, 39100 Liberty St, Fremont CA 94538) ; ;============================================================================== ; Add global entry point vtstat for use by Status in mssset. ; Clear terminal emulation flag, flags.vtflg, in procedure lclini. ; Add register save/restore in procedure getbaud. ; Bump rev level to 6. Joe R. Doupnik 12 March 1986 ; Add global procedures ihosts and ihostr to handle host initialization ; when packets are to be sent or received by us,resp. 24 March 1986 ; Add global procedure dtrlow (without worker serhng) to force DTR & RTS low ; in support of Kermit command Hangup. Says Not Yet Implemented. [jrd] ; Add global procedure Dumpscr, called by Ter in file msster, to dump screen ; to a file. Just does a beep for now. 13 April 1986 [jrd] ; In proc Outchr add override of xon from chkxon sending routine. ; This makes a hand typed Xoff supress the xon flow control character sent ; automatically as the receiver buffer empties. 20 April 1986 [jrd] include mssdef.h public xofsnt, machnam, setktab, setkhlp, count public serini, serrst, clrbuf, outchr, coms, vts, vtstat, dodel public ctlu, cmblnk, locate, lclini, prtchr, dobaud, clearl public dodisk, getbaud, beep, puthlp, poscur, putmod, clrmod public sendbr, showkey public ihosts, ihostr, dtrlow, dumpscr ; [jrd] ;========================================================================= ; Data Segment variables for Ti-Pro ; ; external variables used: ; drives - # of disk drives on system ; flags - global flags as per flginfo structure defined in pcdefs ; portval - pointer to current portinfo structure (currently either port1 ; or port2) ; port1, port2 - portinfo structures for the corresponding ports ; ; global variables defined in this module: ; xofsnt, xofrcv - tell whether we saw or sent an xoff. ;========================================================================= datas segment public 'datas' extrn drives:byte,flags:byte, dmpname:byte ; [jrd] extrn portval:word,port1:byte,port2:byte,port3:byte,port4:byte false equ 0 true equ 1 mntrgh equ bufsiz*3/4 ;High trigger point for XOFF machnam db 'TI-PRO (Revision ',REVLVL+'0',')$' badbd db cr,lf,'Unimplemented baud rate$' hngmsg db cr,lf,' The phone should have hungup.',cr,lf,'$' ; [jrd] hnghlp db cr,lf,' The modem control lines DTR and RTS for the current' db ' port are forced low (off)' db cr,lf,' to hangup the phone. Normally, Kermit leaves them' db ' high (on) when it exits.' db cr,lf,'$' ; [jrd] rdbuf db 80 dup (?) ; temp buf [jrd] noimp db cr,lf,'?Not implemented.$' ; [jrd] shkmsg db 'Not implemented.' shklen equ $-shkmsg setktab db 0 ;Must be defined. Used in Set Key command setkhlp db 0 ;Must be defined. Used in Set Key ? crlf db cr,lf,'$' delstr db bs,bs,' ',bs,'$';Delete string. clrlin db cr ;Must be at clreol-1 clreol db esc,'[K$' ;Clear line. homeras db esc,'[H',esc,'[J$' ;Home and erase savint dw 0,0 ;Place to save interrupt vector invvid db esc,'[0;7m$' ;Inverse video norvid db esc,'[0;1m$' ;Normal video (WHITE=BOLD, as opposed to GREEN) xofsnt db 0 ;Say if we sent an XOFF. xofrcv db 0 ;Say if we received an XOFF. portin db 0 ;Non-zero if port is initialized source db bufsiz dup(?) ;Circular buffer for data from port savedi dw 0 ;Input pointer for circular buffer savesi dw 0 ;Output pointer for circular buffer count dw 0 ;Number of characters in buffer porttab db 04h ;4 entries db 01h,'1$' dw 01h db 01h,'2$' dw 02h ;*** NOTE: This is 2, not 0 **** db 01h,'3$' dw 03h db 01h,'4$' dw 04h ontab db 2 ;Number of entries db 03h,'OFF$' dw 0 db 02h,'ON$' dw 1 modem mdminfo <0e7h,0e6h,0e4h,0feh,001h,000h,40h*4> ;Init to Port 1 parms ; Data to init Serial Controller ; Channel A parameters parmta db 09h ;Select WR9 db 0c0h ;Reset 8530 db 0bh ;Select WR11 db 50h ;No XTAL, RxC=BRG=TxC, TRxC pin is an input db 0eh ;Select WR14 db 03h ;BRG source is PCLK pin, enable BRG db 0fh ;Select WR15 db 0 ;Disable external status interrupts db 04h ;Select WR4 db 44h ;x16 clock, 1 stop bit, no parity db 05h ;Select WR5 db 11101010b ;Raise DTR+RTS, 8 bits, Tx enable db 03h ;Select WR3 db 0c1h ;8 bits, enable receiver db 01h ;Select WR1 db 10h ;Interrupt on all receive chars or spec. cond. db 9 ;Select WR9 db 8 ;Master interrupt enable parmas equ $-parmta ; Channel B parameters parmtb db 0fh ;Select WR15 db 00h ;Disable external status interrupts db 01h ;Select WR1 db 00h ;Disable all other interrupts db 05h ;Select WR5 db 02h ;Raise RTSB (RCNTL) for internal modem parmbs equ $-parmtb baudat label word ;Divisors for Z-8530 with 4.9152-MHz oscillator dw 0696h ; 0 45.5 baud dw 05FEh ; 1 50 baud dw 03FEh ; 2 75 baud dw 02B8h ; 3 110 baud (+0.03%) dw 0239h ; 4 134.5 baud (Selectric) dw 01FEh ; 5 150 baud dw 00FEh ; 6 300 baud dw 007Eh ; 7 600 baud dw 003Eh ; 8 1200 baud dw 0029h ; 9 1800 baud (-0.78%) dw 0024h ;10 2000 baud (+1.05%) dw 001Eh ;11 2400 baud dw 000Eh ;12 4800 baud dw 0006h ;13 9600 baud dw 0002h ;14 19.2 kbaud dw 0000h ;15 38.4 kbaud - not supported baudlen equ $-baudat ;Size of table in bytes datas ends ; Serial port routines -- Initialize code segment public 'code' assume cs:code,ds:datas extrn sleep:near ; [jrd] extrn comnd:near,dopar:near ;============================================================================== ; Initialization for using serial port. Returns normally. ; This is called for by SEND, RECEIVE, and CONNECT commands. ;============================================================================== db 'serini' serini proc near cmp portin,2 ;Is it initialized already? jz serinc ;Yes, skip all this cli ;Disable interrupts cld ;Do increments in string operations push es ;Set interrupt vector xor ax,ax mov es,ax ;Point to vector segment push bx ; save reg. [jrd] mov bx,modem.mdintv ;Get vector address for this com port mov ax,es:[bx] mov savint,ax ;Save old vector offset mov ax,offset serint mov es:[bx],ax ;Replace with my offset mov ax,es:[bx+2] mov savint+2,ax ;Save old vector segment mov es:[bx+2],cs ;Replace with my segment pop bx ; [jrd] pop es call clrbuf ;Clear 8530 and memory buffers mov si,offset parmta ;Addr of port A parameter table cmp portin,1 ;1 means reset but dont hang up modem jnz sini10 add si,2 ;Skip over hardware reset to avoid ;hanging up TI internal modems sini10: mov dx,modem.mdstat ;Port A command/status addr in al,dx ;Make sure it's pointing to WR0 mov cx,parmas ;Table size serina: lodsb ;Get a byte out dx,al ;Send it to 8530 loop serina ;Do all of port A mov si,offset parmtb ;Addr of port-B parameter table mov dx,modem.mdcom ;Port B command/status addr in al,dx ;Make sure it's pointing to WR0 mov cx,parmbs serinb: lodsb ;Get a byte out dx,al ;Send it to 8530 loop serinb in al,19h ;Set up 8259a interrupt controller and al,modem.mden ;Enable IR0, IR1, IR2, or IR4 out 19h,al sti ;Allow interrupts serinc: mov portin,2 ;Flag that port is set up ret serini endp ;============================================================================== ; Serial port interrupt handler. This routine gets all serial port interrupts ; and stores any data in a circular buffer. ;============================================================================== db 'serint' serint proc near sti ;Enable interrupts push ax ;Save registers used push bx push dx push di push ds push es cld ;Auto increment mov ax,seg datas mov ds,ax ;Set segment registers mov es,ax mov dx,modem.mdstat ;Get status register in al,dx ;Read RR0 contents and al,1 ;See if any characters in receive FIFO jz sint50 ;Jump if not mov dx,modem.mddat ;Point to data register in al,dx ;Get received character mov bx,portval ;Point to port data structure cmp [bx].parflg,parnon ;Is parity off? jz sint5 ;Jump if it is and al,7fh ;Strip off parity sint5: or al,al ;Throw away nulls jz sint50 cmp [bx].floflg,0 ;Doing flow control? je sint20 ;No mov dx,[bx].flowc ;Flow control char, dh=XON, dl=XOFF cmp al,dl ;Is it an XOFF? jne sint10 ;No, go on mov xofrcv,1 ;Set flag jmp short sint50 sint10: cmp al,dh ;Did we get an XON? jne sint20 ;No, go on mov xofrcv,0 ;Clear XOFF flag jmp short sint50 sint20: mov di,savedi ;Point to buffer location stosb ;Store new char in circular buffer cmp di,offset source+bufsiz ;Is buffer pointer at end? jb sint30 ;No, carry on mov di,offset source ;Wrap buffer pointer to start of buffer sint30: inc count ;Increment number of chars in buffer cmp [bx].floflg,0 ;Doing flow control? je sint40 ;No, just leave cmp xofsnt,1 ;Have we sent an XOFF already? je sint40 ;Yes, don't send another cmp count,mntrgh ;Past the high trigger point? jbe sint40 ;No, the buffer still has room mov ah,dl ;Get the XOFF character call outchr ;Send it nop ;Waste 3 bytes for skip returns nop ; and ignore failures nop mov xofsnt,1 ;Remember we sent it sint40: mov savedi,di ;Update buffer pointer sint50: cli mov al,20h ;Get end of interrupt code out 18h,al ;Send End-of-Interrupt to 8259 pop es ;Restore registers pop ds pop di pop dx pop bx pop ax iret serint endp ;============================================================================== ; Reset the serial port. This is the opposite of SERINI. Calling ; this twice without intervening calls to SERINI should be harmless. ; Returns normally. ;============================================================================== serrst proc near mov portin,1 ;1 means reset all but don't hangup cli ; internal modem mov dx,modem.mdstat ;Point to channel A WR0 mov al,9 out dx,al ;Register 9 write xor al,al nop out dx,al ;disable 8530 interrupts in al,19h ;Disable 8259a IR line or al,modem.mddis out 19h,al push es ;Reset interrupt vector push bx ; save reg. [jrd] xor bx,bx mov es,bx mov bx,modem.mdintv ;Get vector address mov ax,savint mov es:[bx],ax ;Restore saved vector mov ax,savint+2 mov es:[bx+2],ax pop bx ; [jrd] pop es sti ret ;All done. serrst endp ;============================================================================== ; Clear the input buffer. This throws away all the characters in the ; serial interrupt buffer. This is particularly important when ; talking to servers, since NAKs can accumulate in the buffer. ;============================================================================== clrbuf proc near push ax ; save regs. [jrd] push cx push dx mov ax,offset source mov savedi,ax ;Place to put next character received mov savesi,ax ;Place to get next character from mov cx,8 mov dx,modem.mddat ;Address channel-A data register clrbf1: in al,dx ;Clear out anything in the receive FIFO loop clrbf1 mov count,cx ;Set count to zero pop dx pop cx pop ax ret clrbuf endp ;============================================================================== ; Put the char in AH to the serial port. This assumes the ; port has been initialized. Should honor xon/xoff. Skip returns on ; success, returns normally if the character cannot be written. ;============================================================================== db 'outchr' outchr proc near push bx push cx push dx mov bx,portval cmp [bx].floflg,0 ;Are we doing flow control. je outch2 ;No, just continue. xor cx,cx ;clear counter cmp ah,byte ptr [bp].flowc ; sending xoff? [jrd] jne outch1 ; ne = no mov xofsnt,false ; supress xon from chkxon buffer routine outch1: cmp xofrcv,1 ;Are we being held? jne outch2 ;No - it's OK to go on. loop outch1 ;held, try for a while mov xofrcv,0 ;timed out, force it off and fall thru. outch2: mov al,ah ;Parity routine works on AL. call dopar ;Set parity appropriately. mov ah,al ;Preserve character for a bit xor cx,cx ;Set loop counter to max mov dx,modem.mdstat ;Port 1 channel A command/status address outch3: in al,dx ;Get RR0 contents and al,04h ;Transmit buffer empty? jnz outch4 ;Yes, output char loop outch3 ;No, try again jmp outch5 ;Loop counter expired, give up outch4: mov dx,modem.mddat ;Get port 1 channel A data address mov al,ah ;Get the character out dx,al ;Send it pop dx pop cx pop bx jmp rskp ;Skip return for OK outch5: pop dx pop cx pop bx ret ;Non-skip return due to timeout outchr endp ;============================================================================== ; Set the current port. Called from SET PORT command ;============================================================================== coms proc near mov dx,offset porttab ;Point to list of port number keywords mov bx,0 ;No help mov ah,cmkey ;Parse a keyword call comnd jmp r ;Return for errors push bx ;Save port number mov ah,cmcfm call comnd ;Get a confirm. jmp comx ;Didn't get a confirm. error nop ;Need 3 bytes in here call serrst ;Reset previous serial port pop bx ;Restore desired comm port mov flags.comflg,bl ;Set the comm port flag. cmp flags.comflg,1 ;Port 1? jne coms2 ;No, try another mov portval,offset port1 mov modem.mddat,0e7h ;Data reg mov modem.mdstat,0e6h ;Channel A command/status mov modem.mdcom,0e4h ;Channel B command/status mov modem.mddis,01h ;Mask to disable IR0 mov modem.mden,0feh ;Mask to enable IR0 mov modem.mdintv,40h*4 ;Vector for IR0 call serini ret coms2: cmp flags.comflg,2 ;Port 2? jne coms3 ;No, try another mov portval,offset port2 mov modem.mddat,0efh ;Data reg mov modem.mdstat,0eeh ;Channel A command/status mov modem.mdcom,0ech ;Channel B command/status mov modem.mddis,02h ;Mask to disable IR1 mov modem.mden,0fdh ;Mask to enable IR1 mov modem.mdintv,41h*4 ;Vector for IR1 call serini ret coms3: cmp flags.comflg,3 ;Port 3? jne coms4 ;No, try another mov portval,offset port3 mov modem.mddat,0f7h ;Data reg mov modem.mdstat,0f6h ;Channel A command/status mov modem.mdcom,0f4h ;Channel B command/status mov modem.mddis,04h ;Mask to disable IR2 mov modem.mden,0fbh ;Mask to enable IR2 mov modem.mdintv,42h*4 ;Vector for IR2 call serini ret coms4: mov portval,offset port4 mov modem.mddat,0ffh ;Data reg mov modem.mdstat,0feh ;Channel A command/status mov modem.mdcom,0fch ;Channel B command/status mov modem.mddis,10h ;Mask to disable IR4 mov modem.mden,0efh ;Mask to enable IR4 mov modem.mdintv,44h*4 ;Vector for IR4 call serini ret comx: pop bx ret coms endp ;============================================================================== ; Set heath emulation on/off. Called from SET TERMINAL-EMULATION command ;============================================================================== vts proc near mov dx,offset ontab ;Table containing OFF ON keywords mov bx,0 ;No help mov ah,cmkey ;Means parse a keyword call comnd ;Parse for ON or OFF jmp r ;Jump for errors push bx ;Save returned code for ON or OFF mov ah,cmcfm ;Means parse a confirm call comnd ;Wait for confirm jmp short vt0 ;Jump for error nop ;Needs 3 bytes here pop bx ;Restore return status mov flags.vtflg,bl ;Set H19 on/off global variable ret vt0: pop bx ret vts endp VTSTAT PROC NEAR ; For Status display [jrd] ret ; no emulator status to display VTSTAT ENDP ; Save the screen to a buffer and then append buffer to a disk file. [jrd] ; Default filename is Kermit.scn; actual file can be a device too. Filename ; is determined by mssset and is passed as pointer dmpname. DUMPSCR PROC NEAR ; Dumps screen contents to a file. Just Beeps here call beep ; [jrd] ret DUMPSCR ENDP ;============================================================================== ; Delete a character from the terminal. This works by printing ; backspaces and spaces. Returns normally. ;============================================================================== dodel proc near mov ah,9 mov dx,offset delstr ;Backspace-space-backspace int 21h ret dodel endp ;============================================================================== ; Move the cursor to the left margin, then clear to end of line. ; Returns normally. ;============================================================================== ctlu proc near mov ah,9 mov dx,offset clrlin ;Output CR, then clear to end of line int 21h ret ctlu endp ;============================================================================== ; This routine blanks the screen. Returns normally. ;============================================================================== cmblnk proc near mov ah,13h ;Function 13h of INT 49h clears the screen int 49h ret cmblnk endp ;============================================================================== ; Homes the cursor. Returns normally. ;============================================================================== locate proc near xor dx,dx ;Go to top left corner of screen. jmp poscur locate endp ;============================================================================== ; Local initialization ;============================================================================== lclini proc near mov flags.vtflg,0 ; no terminal emulation. [jrd] call beep1 ;In case BASIC left the speaker messed up ret lclini endp ;============================================================================== ; Port read character. Check the port status. If no data, skip ; return. Else, read in a char and return. ;============================================================================== db 'prtchr' prtchr proc near call chkxon ;See if we need to XON first cmp count,0 ;See if anything in buffer jnz pc10 ;Jump if something there jmp rskp ;Skip return since nothing there pc10: mov si,savesi ;Get buffer pointer lodsb ;Get char from buffer cmp si,offset source+bufsiz ;See if past end of buffer jb pc20 ;Jump if not mov si,offset source ;Wrap pointer to start of buffer pc20: dec count ;1 less char in buffer mov savesi,si ;Save buffer pointer mov dx,count ;Return remaining count in DX ret prtchr endp ;============================================================================== ; Local routine to see if we have to transmit an xon ;============================================================================== chkxon proc near push bx mov bx,portval cmp [bx].floflg,0 ;Doing flow control? je chkxo1 ;No, skip all this cmp xofsnt,0 ;Have we sent an xoff? je chkxo1 ;No, forget it cmp count,mntrgh ;Below trigger? jae chkxo1 ;No forget it mov ax,[bx].flowc ;AH gets xon call outchr ;Send XON character nop nop nop ;In case it skips mov xofsnt,0 ;Remember we've sent the XON. chkxo1: pop bx ;Restore register ret ;And return chkxon endp ; IHOSTS - Initialize the host by sending XON, or equivalent, and enter the ; cycle of clear input buffer, wait 1 second, test if buffer empty then exit ; else repeat cycle. Requires that the port be initialized before hand. ; Ihosts is used by the local send-file routine just after initializing ; the serial port. ; 22 March 1986 [jrd] IHOSTS PROC NEAR push ax ; save the registers push bx push cx push dx mov bx,portval ; port indicator mov ax,[bx].flowc ; put Go-ahead flow control char in ah call outchr ; send it (release Host's output queue) nop ; outchr can do skip return nop nop ihosts1:call clrbuf ; clear out interrupt buffer mov ax,1 ; sleep for 1 second call sleep ; procedure sleep is in msscom.asm call prtchr ; check for char at port jmp ihosts1 ; have a char in al, repeat wait/read cycle nop ; prtchr does skip return on empty buffer pop dx ; empty buffer. we are done here. pop cx pop bx pop ax ret IHOSTS ENDP ; IHOSTR - initialize the remote host for our reception of a file by ; sending the flow-on character (XON typically) to release any held ; data. Called by receive-file code just after initializing the serial ; port. 22 March 1986 [jrd] IHOSTR PROC NEAR push ax ; save regs push bx push cx mov bx,portval ; port indicator mov ax,[bx].flowc ; put Go-ahead flow control char in ah call outchr ; send it (release Host's output queue) nop ; outchr can do skip return nop nop pop cx pop bx pop ax ret IHOSTR ENDP DTRLOW PROC NEAR ; Global proc to Hangup the Phone by making ; DTR and RTS low. mov ah,cmtxt ; allow text to be able to display help mov bx,offset rdbuf ; dummy buffer mov dx,offset hnghlp ; help message call comnd ; get a confirm jmp r ; not yet imp. call serhng ; drop DTR and RTS mov ah,prstr ; give a nice message ; not yet imp. mov dx,offset hngmsg mov dx,offset noimp ; for now int dos jmp rskp DTRLOW ENDP ; Hang up the Phone. Similar to SERRST except it just forces DTR and RTS low ; to terminate the connection. 29 March 1986 [jrd] ; Calling this twice without intervening calls to serini should be harmless. ; Returns normally. ; SERHNG is Not Yet Implemented. ;============================================================================== ; Set the baud rate for the current port, based on the value ; in the portinfo structure. Returns normally. ; Called from SET BAUD command with new index in PORT.BAUD, previous in AX ;============================================================================== db 'dobaud' dobaud proc near push bx mov bx,portval ;Get pointer mov bx,[bx].baud ;Get new baud-rate index shl bx,1 ;Multiply by 2 cmp baudat[bx],0 ;Test for zero jne dobod1 ;Nonzero is OK mov bx,portval ;Error, get back to data structure mov [bx].baud,ax ;Restore previous baud rate number mov ah,9 mov dx,offset badbd ;Bad baud rate int 21h pop bx ret dobod1: mov ax,baudat[bx] ;Get BRG divisor call setbaud ;Send AX to baud-rate-divisor pop bx ret dobaud endp ;============================================================================== ; Local routine to send AX to the Baud Rate Generator. Preserves all regs ;============================================================================== setbaud proc near push dx push ax ;Save rate mov dx,modem.mdstat ;Address the channel-A command port mov al,13 ;Point to register 13 out dx,al jmp short $+2 ;Slight delay to let hardware respond mov al,ah ;High-order part of divisor out dx,al jmp short $+2 mov al,12 ;Point to register 12 out dx,al jmp short $+2 pop ax out dx,al ;Low-order part of divisor pop dx ret setbaud endp ;============================================================================== ; Clear to the end of the current line. Returns normally. ;============================================================================== clearl proc near mov ah,9 mov dx,offset clreol ;Erase from cursor to end of line int 21h ret clearl endp ;============================================================================== ; this is called by Kermit initialization. It checks the ; number of disks on the system, sets the drives variable ; appropriately. Returns normally. ;============================================================================== dodisk proc near mov ah,gcurdsk ;Current disk value to AL. int 21h mov dl,al ;Put current disk in DL. mov ah,seldsk ;Select current disk. int 21h ;Returns number of drives in AL. mov drives,al ;Set global variable ret dodisk endp ;============================================================================== ; Get the current baud rate from the serial card and set it ; in the portinfo structure for the current port. Returns normally. ; This is used during initialization. ;============================================================================== getbaud proc near push ax ; save some regs. [jrd] push bx ; [jrd] push dx ; [jrd] mov dx,modem.mdstat ;Address channel-A command port mov al,13 ;Point to register 13 out dx,al jmp short $+2 ;Small delay in al,dx ;Read RR13 mov ah,al ;Save high-order part mov al,12 ;Point to register 12 out dx,al jmp short $+2 in al,dx ;Read RR12 ;Baud rate = (300*256)/(AX+2) mov bx,0 ;Index value getbd1: cmp ax,baudat[bx] ;See if known value je getbd2 ;Found it add bx,2 ;Point to next word cmp bl,baudlen ;End of table? jl getbd1 ;No, keep looking mov bx,B1200*2 ;Yes, force it to 1200 baud mov ax,baudat[bx] call setbaud getbd2: mov ax,bx ;Get the byte index shr ax,1 ;Reduce to number from 0 to 15 mov bx,portval ;Point to structure mov [bx].baud,ax ;Store where SHOW processor can see it pop dx ; restore regs. [jrd] pop bx ; [jrd] pop ax ; [jrd] ret getbaud endp ;============================================================================== ; Produce a short beep. The PC DOS bell is long enough to cause a loss ; of data at the port. Returns normally. ;============================================================================== beep1 proc near mov ah,2 ;Set speaker frequency mov cx,1000 ;Approx 1.5 kHz int 48h ret beep1 endp beep proc near call beep1 ;Set the frequency mov ah,0 ;Timed beep function mov al,5 ;5/40 = 1/8 second int 48h ret beep endp ;============================================================================== ; Put a help message on the screen. ; Pass the message in ax, terminated by a null. Returns normally. ;============================================================================== puthlp proc near push ax ;preserve this mov ah,9 mov dx,offset crlf int 21h pop si ;point to string again puthl3: lodsb ;get a byte cmp al,0 ;end of string? je puthl4 ;yes, stop mov dl,al mov ah,6 int 21h ;else write to screen jmp puthl3 ;and keep going puthl4: mov ah,9 mov dx,offset crlf int 21h ret puthlp endp ;============================================================================== ; Write a line at the bottom of the screen... ; the line is passed in dx, terminated by a $. Returns normally. ;============================================================================== putmod proc near push dx ;preserve message mov dx,24*100h ;now address line 24 call poscur mov dx,offset invvid mov ah,9 int 21h ;Set inverse video pop dx ;get message back mov ah,9 int 21h ;write it out mov dx,offset norvid mov ah,9 int 21h ;Normal video ret ;and return putmod endp ;============================================================================== ; Clear the mode line written by PUTMOD. Returns normally. ;============================================================================== clrmod proc near mov dx,1800h call poscur ;Go to bottom row. call clearl ;Clear to end of line. ret clrmod endp ;============================================================================== ; Position the cursor according to contents of DX: ; DH contains row, DL contains column. Returns normally. ;============================================================================== poscur proc near xchg dh,dl ;BIOS wants row in DL, Col in DH mov ah,2 ;Locate cursor function int 49h ret poscur endp ;============================================================================== ; Send a break out the current serial port. Returns normally. ;============================================================================== sendbr proc near push cx push dx push ax xor cx,cx ;Clear loop counter. mov dx,modem.mdstat ;Address channel-A command port mov al,5 ;Point to register 5 out dx,al jmp short $+2 in al,dx ;Get current setting. mov ah,al ;Copy the bits mov al,5 ;Point back to register 5 out dx,al mov al,ah ;Get old bits or al,10h ;Set send-break bit out dx,al ;Start the break pause: loop pause ;Wait a while. mov al,5 ;Point to register 5 out dx,al jmp short $+2 mov al,ah ;Clear send-break bit out dx,al ;Stop the break pop ax pop dx pop cx ret ;And return. ret sendbr endp ;============================================================================== ; Called by the SHOW KEY command ;============================================================================== showkey proc near mov ax,offset shkmsg mov cx,shklen ret showkey endp ;============================================================================== ; Jumping to this location is like retskp. It assumes the instruction ; after the call is a jmp addr. ;============================================================================== rskp proc near pop bp add bp,3 push bp ret rskp endp ;============================================================================== ; Jumping here is the same as a ret. The jump to here uses up the 3 bytes ;============================================================================== r proc near ret r endp code ends end