-f100 500 0 -a100 1149:0100 ; 1149:0100 ;---------------------------------------- 1149:0100 ; DOSMON - DOS Activity Monitor 1149:0100 ;---------------------------------------- 1149:0100 ; 1149:0100 ; This program will terminate and stay resident. It intercepts the 1149:0100 ; DOS service interrupt and displays status information on the 1149:0100 ; screen during DOS service execution periods. 1149:0100 ; 1149:0100 ; S.H.Smith, 15-may-86 1149:0100 ; 1149:0100 - -a100 1149:0100 ;---------------------------------------- 1149:0100 ; startup entry point 1149:0100 ;---------------------------------------- 1149:0100 jmp 2e0 ;install 1149:0103 - -a103 1149:0103 ; vector for old interrupt 1149:0103 db 0,0,0,0 1149:0107 - -a107 1149:0107 ; segment address for display memory 1149:0107 ; filled in by startup code 1149:0107 dw 0 1149:0109 - -a10e 1149:010E ; twiddle display index 1149:010E dw 0 1149:0110 - -a110 1149:0110 ; twiddle display characters 1149:0110 db "Ä\³/" 1149:0114 - -a118 1149:0118 ; 118..11B used for vector back to user 1149:0118 ; 11c used for first save char 1149:0118 ; 11e used for second save char 1149:0118 ; 120 used for third save char 1149:0118 ; 122 scratch ax save 1149:0118 ; 124 ss save 1149:0118 ; 126 sp save 1149:0118 - -a130 1149:0130 ; a signature in bytes 1149:0130 db 0a,0d,'DOSMON - DOS Activity Monitor',0a,0d 1149:0151 db '$ S.H.Smith, 15-May-86',0a,0d 1149:016A db 1a 1149:016B - -a170 1149:0170 ;---------------------------------------- 1149:0170 ; new DOS service interrupt 1149:0170 ;---------------------------------------- 1149:0170 ; 1149:0170 cs: 1149:0171 pop [118] ;get return ip 1149:0175 cs: 1149:0176 pop [11a] ;get return cs 1149:017A popf ;get flags 1149:017B ; 1149:017B pushf 1149:017C push ds 1149:017D push es 1149:017E push bx ;save entry registers 1149:017F push ax 1149:0180 ; 1149:0180 ;---------------------------------------- 1149:0180 ; save the previous display data 1149:0180 ; 1149:0180 cs: 1149:0181 mov ax,[107] ;get display segment into es 1149:0184 mov es,ax 1149:0186 ; 1149:0186 es: 1149:0187 mov ax,[94] ;save original screen contents 1149:018A cs: 1149:018B mov [11c],ax 1149:018E ; 1149:018E es: 1149:018F mov ax,[96] ;second char 1149:0192 cs: 1149:0193 mov [11e],ax 1149:0196 ; 1149:0196 es: 1149:0197 mov ax,[98] ;third char 1149:019A cs: 1149:019B mov [120],ax 1149:019E ; 1149:019E ;---------------------------------------- 1149:019E ; prepare display with blanks 1149:019E ; 1149:019E mov ax,0f20 ;space with attribute of 15 1149:01A1 es: 1149:01A2 mov [94],ax 1149:01A5 es: 1149:01A6 mov [96],ax ;set attribute of the function code locations 1149:01A9 es: ;and leave them blank in case of 'exec' function 1149:01AA mov [98],ax 1149:01AD ; 1149:01AD pop ax ;get DOS function code into ah 1149:01AE push ax 1149:01AF ; 1149:01AF cmp ah,4b ;is this an exec call? 1149:01B2 jz 228 ;leave display blank if so 1149:01B4 ; 1149:01B4 ;---------------------------------------- 1149:01B4 ; display the rotating twiddle character 1149:01B4 ; 1149:01B4 cs: 1149:01B5 mov bx,[10e] ;get twiddle index 1149:01B9 inc bx 1149:01BA mov al,bl ;advance to next twiddle position 1149:01BC and al,3 ;bx=bx mod 4 to rotate through twiddles 1149:01BE mov bl,al 1149:01C0 cs: 1149:01C1 mov [10e],bx ;save next twiddle index 1149:01C5 ; 1149:01C5 cs: 1149:01C6 mov ah,[110+bx] ;get the next twiddle character 1149:01CA es: 1149:01CB mov [94],ah ;put twiddle status on screen 1149:01CF ; 1149:01CF ;---------------------------------------- 1149:01CF ; display the DOS service number in hex 1149:01CF ; 1149:01CF pop ax ;get the dos function code into ah 1149:01D0 push ax 1149:01D1 ; 1149:01D1 and ah,0f 1149:01D4 add ah,30 ;convert low digit to hex 1149:01D7 ; 1149:01D7 cmp ah,3a ;handle A..F 1149:01DA jb 1e8 1149:01DC add ah,7 1149:01DF jmp 1e8 1149:01E1 - -a1e8 1149:01E8 es: 1149:01E9 mov [98],ah ;and set LSB on screen 1149:01ED ; 1149:01ED pop ax ;get fresh copy of function code into ah 1149:01EE push ax 1149:01EF ; 1149:01EF shr ah,1 ;move down bits for high digit 1149:01F1 shr ah,1 1149:01F3 shr ah,1 1149:01F5 shr ah,1 ;make high byte hex and put on screen 1149:01F7 and ah,0f 1149:01FA add ah,30 1149:01FD ; 1149:01FD cmp ah,3a ;handle A..F 1149:0200 jb 218 1149:0202 add ah,7 1149:0205 jmp 218 1149:0207 - -a218 1149:0218 es: 1149:0219 mov [96],ah ;set MSB on screen 1149:021D jmp 228 1149:021F - -a228 1149:0228 ;---------------------------------------- 1149:0228 ; perform the DOS service function 1149:0228 ; 1149:0228 pop ax 1149:0229 pop bx 1149:022A pop es ;restore initial entry registers 1149:022B pop ds 1149:022C popf 1149:022D ; 1149:022D cs: 1149:022E push [118] 1149:0232 cs: ;push static variables to make this program 1149:0233 push [11a] ;recursive - DOS uses many recursive functions 1149:0237 cs: 1149:0238 push [11c] 1149:023C cs: 1149:023D push [11e] 1149:0241 cs: 1149:0242 push [120] 1149:0246 cs: 1149:0247 push [124] 1149:024B cs: 1149:024C push [126] 1149:0250 ; 1149:0250 cs: 1149:0251 mov [122],ax 1149:0254 mov ax,ss 1149:0256 cs: 1149:0257 mov [124],ax ;preserve ss:sp in case dos loses it! 1149:025A mov ax,sp 1149:025C cs: 1149:025D mov [126],ax 1149:0260 cs: 1149:0261 mov ax,[122] 1149:0264 ; 1149:0264 pushf ;push flags to simulate action of 'int 21' 1149:0265 cs: 1149:0266 call far [103] ;call the real DOS service interrupt 1149:026A ; 1149:026A cs: 1149:026B mov [122],ax 1149:026E cs: 1149:026F mov ax,[124] ;restore ss:sp 1149:0272 mov ss,ax 1149:0274 cs: 1149:0275 mov ax,[126] 1149:0278 mov sp,ax 1149:027A cs: 1149:027B mov ax,[122] 1149:027E ; 1149:027E cs: 1149:027F pop [126] 1149:0283 cs: 1149:0284 pop [124] 1149:0288 cs: 1149:0289 pop [120] 1149:028D cs: 1149:028E pop [11e] ;restore static variables after return from recursion 1149:0292 cs: 1149:0293 pop [11c] 1149:0297 cs: 1149:0298 pop [11a] 1149:029C cs: 1149:029D pop [118] 1149:02A1 ; 1149:02A1 pushf 1149:02A2 push ax ;save DOS exit registers for later use 1149:02A3 push es 1149:02A4 push ds 1149:02A5 ; 1149:02A5 ;---------------------------------------- 1149:02A5 ; restore original screen contents 1149:02A5 ; 1149:02A5 cs: 1149:02A6 mov ax,[107] ;get display page into es 1149:02A9 mov es,ax 1149:02AB ; 1149:02AB cs: 1149:02AC mov ax,[11c] 1149:02AF es: ;put old data on screen 1149:02B0 mov [94],ax ;first char 1149:02B3 ; 1149:02B3 cs: 1149:02B4 mov ax,[11e] 1149:02B7 es: 1149:02B8 mov [96],ax ;second char 1149:02BB ; 1149:02BB cs: 1149:02BC mov ax,[120] 1149:02BF es: 1149:02C0 mov [98],ax ;third char 1149:02C3 ; 1149:02C3 ;---------------------------------------- 1149:02C3 ; end of interrupt - return to the caller 1149:02C3 ; 1149:02C3 pop ds 1149:02C4 pop es 1149:02C5 pop ax 1149:02C6 popf ;get return flags 1149:02C7 cs: 1149:02C8 jmp far [118] ;jump back to user code 1149:02CC - -a2e0 1149:02E0 ;---------------------------------------- 1149:02E0 ; startup code 1149:02E0 ;---------------------------------------- 1149:02E0 ; determine where the video ram is. this is done by putting a special 1149:02E0 ; character on the screen and then looking for it in the various video 1149:02E0 ; ram locations. 1149:02E0 ; 1149:02E0 push cs 1149:02E1 pop ds 1149:02E2 ; 1149:02E2 mov ah,3 ;get cursor position 1149:02E4 int 10 ;video bios service 1149:02E6 push ax 1149:02E7 push bx 1149:02E8 push dx ;save it for later 1149:02E9 ; 1149:02E9 mov dx,0 1149:02EC mov ah,2 ;home the cursor 1149:02EE int 10 1149:02F0 ; 1149:02F0 mov ah,0A 1149:02F2 mov al,88 ;display a funny char at cursor 1149:02F4 mov cx,1 1149:02F7 int 10 1149:02F9 ; 1149:02F9 ; move cursor back to original position 1149:02F9 ; 1149:02F9 pop dx 1149:02FA pop bx 1149:02FB pop ax 1149:02FC mov ah,2 1149:02FE int 10 1149:0300 ; 1149:0300 ; look for MONO video ram 1149:0300 ; 1149:0300 mov dl,88 1149:0302 mov ax,b000 1149:0305 mov es,ax 1149:0307 es: 1149:0308 cmp dl,[0] 1149:030C jz 360 1149:030E ; 1149:030E ; look for COLOR video ram 1149:030E ; 1149:030E mov ax,b800 1149:0311 mov es,ax 1149:0313 es: 1149:0314 cmp dl,[0] 1149:0318 jz 360 1149:031A ; 1149:031A ; couldn't find video ram; display a message and abort 1149:031A ; 1149:031A mov dx,308 1149:031D mov ah,9 1149:031F int 21 ;display error message 1149:0321 int 20 ;terminate program 1149:0323 - -a328 1149:0328 db "ERROR: Can't find display memory$" 1149:0349 - -a360 1149:0360 ; 1149:0360 cs: 1149:0361 mov [107],ax ;set the display segment 1149:0364 ; 1149:0364 ;---------------------------------------- 1149:0364 ; display the program signon message now that we are sure 1149:0364 ; that we can be installed 1149:0364 ; 1149:0364 mov dx,130 1149:0367 mov ah,9 1149:0369 int 21 ;display signon message 1149:036B ; 1149:036B ;---------------------------------------- 1149:036B ; now install new interrupt handler 1149:036B ; 1149:036B mov ax,0 1149:036E mov es,ax 1149:0370 ; 1149:0370 ; save old DOS service vector 1149:0370 ; 1149:0370 es: 1149:0371 mov ax,[84] 1149:0374 cs: 1149:0375 mov [103],ax 1149:0378 ; 1149:0378 es: 1149:0379 mov ax,[86] 1149:037C cs: 1149:037D mov [105],ax 1149:0380 ; 1149:0380 ; install new vector 1149:0380 ; 1149:0380 mov ax,170 ;entry point offset 1149:0383 es: 1149:0384 mov [84],ax 1149:0387 ; 1149:0387 mov ax,cs ;this code segment 1149:0389 es: 1149:038A mov [86],ax 1149:038D ; 1149:038D ; set last resident code offset 1149:038D ; and terminate-and-stay-resident 1149:038D ; 1149:038D mov al,0 ;exit code 1149:038F mov dx,30 ;paragraphs to keep resident 1149:0392 mov ah,31 ;keep process function 1149:0394 int 21 ;terminate and stay in memory 1149:0396 - -rcx CX 0000 :400 -ndosmon.com -w Writing 0400 bytes -q