Ham Radio 2000 #1

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/ Ham Radio 2000 #1 / Ham Radio 2000.iso / ham2000 / tcp_ip / ka9q / expiry / command.asm < prev next >

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Assembly Source File | 1990-05-01 | 13.3 KB | 619 lines

.MODEL MEMMOD,C LOCALS %MACS .LALL comment \ To install this into Karn's NET, make the following changes to pc.c, and add command.obj to the makefile's PCOBJS and pc.tl. This version works with "890405 NOS (TurboC large model)". -russ nelson *** orig/pc.c --- pc.c ************** *** 42,47 char *rp; int cnt; } Keyboard; /* Called at startup time to set up console I/O, memory heap */ ioinit(mem) --- 42,48 ----- char *rp; int cnt; } Keyboard; + int Nokeys = 0; /* true if we ignore keystrokes */ /* Called at startup time to set up console I/O, memory heap */ ioinit(mem) ************** *** 135,140 int ret; #ifdef __TURBOC__ ioctl(fileno(stdout), 1, ioctl(fileno(stdout), 0) & 0xff & ~0x20); /* put stdout in cooked mode */ if((command = getenv("COMSPEC")) == NULLCHAR) command = "/COMMAND.COM"; --- 136,149 ----- int ret; #ifdef __TURBOC__ + if (!start_back()) + return -1; + + Nokeys++; + ioctl(fileno(stdout), 1, ioctl(fileno(stdout), 0) & 0xff & ~0x20); /* put stdout in cooked mode */ if((command = getenv("COMSPEC")) == NULLCHAR) command = "/COMMAND.COM"; ************** *** 141,146 ret = spawnv(P_WAIT,command,argv); ioctl(fileno(stdout), 1, ioctl(fileno(stdout), 0) & 0xff | 0x20); /* put stdout in raw mode */ return ret; #else struct sgttyb ttybuf,ttysav; --- 150,161 ----- ret = spawnv(P_WAIT,command,argv); ioctl(fileno(stdout), 1, ioctl(fileno(stdout), 0) & 0xff | 0x20); /* put stdout in raw mode */ + + Nokeys--; + stop_back(); + return ret; #else struct sgttyb ttybuf,ttysav; ************** *** 168,173 int sig = 0; int c; while((c = kbraw()) != -1 && Keyboard.cnt < KBSIZE){ sig = 1; *Keyboard.wp++ = c; --- 190,197 ----- int sig = 0; int c; + if (Nokeys) + return; while((c = kbraw()) != -1 && Keyboard.cnt < KBSIZE){ sig = 1; *Keyboard.wp++ = c; \ ; extrn extern_call: far extrn pwait: far .DATA db 4096 dup(?) stack label byte .CODE dbase dw @Data segoff struc offs dw ? segm dw ? segoff ends main_subr dw ? their_8h dd ? their_10h dd ? their_13h dd ? their_1Bh dd ? their_21h dd ? their_23h dd ? their_24h dd ? their_28h dd ? their_2fh dd ? dos_segment dw ? ;segment of internal DOS flags indos_offset dw ? ;offset of INDOS flag errflag_offset dw ? ;offset of critical error flag program_status db 0 ;popup status flag_10h db 0 ;status of interrupt 10h flag_13h db 0 ;status of interrupt 13h zflag db ? ;save and restore critical error. dos_version db ? ;dos major version. main_countdown db 20 ss_register dw ? ;SS register storage sp_register dw ? ;SP register storage my_psp dw ? ;our PSP. their_psp dw ? ;PSP segment storage tick_counter dw ? indos_counter dw ? errflag_counter dw ? status_counter dw ? bp_counter dw ? main_counter dw ? their_dta dd ? ; ;------------------------------------------------------------------------------ ;Interrupt 8 handling routine. ;------------------------------------------------------------------------------ timer: pushf ;call BIOS routine call their_8h inc tick_counter cmp program_status,0 ;are we already running? jne timer_status ;yes, then suspend ticking. cmp flag_10h,0 ;video flag set? jne timer_exit ;yes, then exit cmp flag_13h,0 ;disk flag set? jne timer_exit ;yes, then exit push es ;save ES and DI push di mov es,dos_segment ;check INDOS flag mov di,indos_offset cmp byte ptr es:[di],0 jne timer_indos ;exit if it's set mov di,errflag_offset ;check critical error flag cmp byte ptr es:[di],0 jne timer_errflag ;exit if it's set mov main_subr,offset cycle call main ;call body of program pop di pop es timer_exit: iret timer_indos: inc indos_counter pop di ;restore registers pop es iret timer_errflag: inc errflag_counter pop di ;restore registers pop es iret timer_status: inc status_counter iret ; ;------------------------------------------------------------------------------ ;Interrupt 10h handling routine. ;------------------------------------------------------------------------------ video: pushf ;push flags onto stack inc flag_10h ;increment flag call their_10h ;call BIOS routine dec flag_10h ;decrement flag iret ; ;------------------------------------------------------------------------------ ;Interrupt 13h handling routine. ;------------------------------------------------------------------------------ my_13: pushf ;push flags onto stack inc flag_13h ;set 'busy' flag call their_13h ;call BIOS routine pushf ;save output flags dec flag_13h ;clear flag popf ;restore output flags retf 2 ;exit without destroying flags ; ;------------------------------------------------------------------------------ ;Interrupt 2fh handling routine. ;------------------------------------------------------------------------------ my_2f: cmp ah,0a9h ;is this our 2f number? jne my_2f_1 cmp al,0 ;get installed state? jne my_2f_2 mov al,-1 ;yes - return "installed". iret my_2f_2: mov main_subr,offset external_call call main iret my_2f_1: jmp their_2fh ; ;------------------------------------------------------------------------------ ;Interrupt 28h handling routine. ;------------------------------------------------------------------------------ my_28: pushf ;call original routine call their_28h inc bp_counter cmp program_status,0 ;are we already running? jne bp_exit ;yes, don't enter it again. cmp flag_10h,0 ;video flag set? jne bp_exit ;yes, then exit cmp flag_13h,0 ;disk flag set? jne bp_exit ;yes, then exit push es ;save ES and DI push di mov es,dos_segment ;check critical error flag mov di,errflag_offset cmp byte ptr es:[di],0 pop di ;clean up the stack pop es jne bp_errflag mov main_subr,offset cycle call main ;call main routine bp_exit: iret ;done - exit bp_errflag: inc errflag_counter iret ;done - exit ; ;------------------------------------------------------------------------------ ;Interrupt 21h handling routine. ;------------------------------------------------------------------------------ my_21: pushf ;save the flags or ah,ah ;Doing function zero? je jump_to_dos ;If yes, take the jump cmp ah,4bh ;Doing EXEC function? je jump_to_dos ;If yes, take the jump popf pushf call cs:their_21h ;Do the DOS function pushf ;Save the result flags cmp cs:program_status,0 ;are we already running? jne no_recursion ;yes, don't recurse. dec cs:main_countdown jne no_recursion mov cs:main_countdown,20 mov main_subr,offset cycle call main ;Safe to access disk now no_recursion: popf ;Recover DOS result flags sti ;Must return with interrupts on retf 2 ;Return with DOS result flags jump_to_dos: popf jmp cs:their_21h ; ;------------------------------------------------------------------------------ ;Interrupt 24h handling routine (DOS 3.X only). ;------------------------------------------------------------------------------ my_24: mov al,3 ;fail the call in progress ioexit: iret ;give control back to DOS external_call: ; call extern_call ret cycle: xor ax,ax ;push a null pointer. push ax push ax call pwait add sp,4 ret ; ;------------------------------------------------------------------------------ ;MAIN is the routine called periodically. ;------------------------------------------------------------------------------ main: inc main_counter mov program_status,1 ;set program active flag cli ;make sure interrupts are off mov ss_register,ss ;save stack registers mov sp_register,sp mov ss,cs:dbase ; establish interrupt data segment mov sp,offset stack sti ;enable interrupts push ax push bx push cx push dx push si push di push ds push es push bp ; ;Set DS and ES segment registers. ; push cs ;set DS to code segment pop ds assume ds:seg dos_version ; ;Save the current active PSP address and activate this PSP. ; mov zflag,0 ;clear flag cmp dos_version,2 ;DOS version 2.X? jne main5 mov es,dos_segment ;point ES:DI to INDOS mov di,indos_offset cmp byte ptr es:[di],0 ;INDOS clear? je main5 ;yes, then branch mov di,errflag_offset ;point ES:DI to error flag cmp byte ptr es:[di],0 ;critical error flag clear? jne main5 ;no, then branch mov byte ptr es:[di],1 ;set critical error flag manually mov zflag,1 ;set change flag main5: mov ah,51h ;get current PSP segment int 21h mov their_psp,bx ;save it mov ah,50h ;make this the active PSP mov bx,my_psp int 21h cmp zflag,0 ;ZFLAG clear? je main6 ;yes, then branch mov di,errflag_offset ;point ES:DI to error flag mov byte ptr es:[di],0 ;restore error flag value main6: ; ;Reset the interrupt 1Bh, 23h, and 24h vectors. ; call ioset ;reset interrupt vectors ; ;Save the current dta and subdirectory ; mov ah,2fh ;get disk transfer address int 21h mov their_dta.segm,es mov their_dta.offs,bx ; ;Call the commutator loop of net until nothing gets queued up. ; mov ds,cs:dbase ; establish interrupt data segment assume ds:nothing call main_subr ; ;Restore the current dta and subdirectory ; lds dx,their_dta mov ah,1ah int 21h ; ;Restore interrupt vectors and former active PSP. ; mov ah,50h ;restore active PSP label mov bx,their_psp int 21h call ioreset ;restore interrupt vectors ; ;Restore registers and stack before exit. ; pop bp ;restore registers and exit pop es pop ds pop di pop si pop dx pop cx pop bx pop ax cli ;interrupts off mov ss,ss_register ;switch to original stack mov sp,sp_register sti ;interrupts on mov program_status,0 ;clear status flag ret ; intset: ;enter with al = interrupt number, cs:dx = offset of new interrupt, ; cs:di -> place to store old interrupt. push es ;get the old interrupt into es:bx push ds ;now set the new interrupt to ds:dx. mov bx,cs mov ds,bx mov ah,35h int 21h mov [di].segm,es ;and store it into ds:di. mov [di].offs,bx mov ah,25h int 21h pop ds pop es ret intreset: ;enter with al = interrupt number, di -> old interrupt. push ds mov ah,25h lds dx,cs:[di] int 21h pop ds ret ;------------------------------------------------------------------------------ ;IOSET vectors interrupts 1Bh, 23h and 24h to internal handlers. IORESET ;restores the original vector values. ;------------------------------------------------------------------------------ ioset: mov al,1bh mov di,offset their_1Bh mov dx,offset ioexit call intset mov al,23h mov di,offset their_23h mov dx,offset ioexit call intset mov al,24h mov di,offset their_24h mov dx,offset my_24 call intset ret ; ioreset: mov al,24h mov di,offset their_24h call intreset mov al,23h mov di,offset their_23h call intreset mov al,1Bh mov di,offset their_1Bh call intreset ret public start_back start_back proc ; ;Remember our psp. ; mov ah,51h ;get current PSP segment int 21h mov my_psp,bx ;save it ; ;Determine which version of DOS is running. ; init3: mov ah,30h ;DOS function 30h int 21h mov dos_version,al ;major version number ; ;Get and save the address of the INDOS flag. ; mov ah,34h ;function 34h int 21h ;get address mov dos_segment,es ;save segment mov indos_offset,bx ;save offset ; ;Get and save the address of the critical error flag. ; mov ax,3E80h ;CMP opcode mov cx,2000h ;max search length mov di,bx ;start at INDOS address init4: repne scasw ;do the search jcxz init5 ;branch if search failed cmp byte ptr es:[di+5],0BCh ;verify this is it je found ;branch if it is jmp init4 ;resume loop if it's not init5: mov cx,2000h ;search again inc bx ;search odd addresses this time mov di,bx init6: repne scasw ;look for the opcode jcxz notfound ;not found if loop expires cmp byte ptr es:[di+5],0BCh ;verify this is it je found jmp init6 notfound: xor ax,ax ret found: mov ax,es:[di] ;get flag offset address mov errflag_offset,ax ;save it ; ;Save and replace all required interrupt vectors. ; mov al,08h mov dx,offset timer mov di,offset their_8h call intset mov al,10h mov dx,offset video mov di,offset their_10h call intset mov al,13h mov dx,offset my_13 mov di,offset their_13h call intset mov al,28h mov dx,offset my_28 mov di,offset their_28h call intset mov al,2fh mov dx,offset my_2f mov di,offset their_2fh call intset mov al,21h mov dx,offset my_21 mov di,offset their_21h call intset mov ax,1 ret start_back endp public stop_back stop_back proc mov cs:program_status,1 mov al,08h mov di,offset their_8h call intreset mov al,10h mov di,offset their_10h call intreset mov al,13h mov di,offset their_13h call intreset mov al,28h mov di,offset their_28h call intreset mov al,2fh mov di,offset their_2fh call intreset mov al,21h mov di,offset their_21h call intreset mov cs:program_status,0 mov dx,ds mov ax,offset tick_counter ret stop_back endp end