Reverse Code Engineering RCE CD +sandman 2000

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Assembly Source File | 1996-02-21 | 43.9 KB | 1,311 lines

;*************************************************************** ;* Show87 - (C) Copyright 1988, 1993 by Borland International * ;* Used with permission of author * ;*************************************************************** ; title 'Turbo Assembler SHOW87 Program', '8087 State Display' page 65,72 ;============================================================================= ; ; This a memory resident program to display the present state of an ; installed 8087 coprocessor. Once assembled, to execute, type: ; ; SHOW87 [/r] ; ; If run without any options, the program executes a DOS shell and can be ; removed from memory by typing EXIT at any DOS prompt. If run with the ; /r option, the progam is made resident and cannot be removed (but uses ; less memory). Uses about 5600 bytes of memory with /r, over 8000 without. ; Requires CONVERT1.INC, CONVERT2.INC, VIDEO1.INC, and VIDEO2.INC on the ; default drive/path for assembly. ; ; The hot key is ALT-7. Traps interrupt 09H and uses only BIOS routines for ; display, thus should work on most computers with most software. ; ; ;---------------------------------------------------------------------------- ;8 Ins Ptr XXXXX | Prec XX | ST(0) +X.XXXXXXXXXXXXXXXXX +XXXXX XXXXXX S ;0 Opr Ptr XXXXX | Round XXXXX | ST(1) +X.XXXXXXXXXXXXXXXXX +XXXXX XXXXXX H ;8 Op Code XXXX | Infin XXXXX | ST(2) +X.XXXXXXXXXXXXXXXXX +XXXXX XXXXXX O ;7 Control XXXX |------------- | ST(3) +X.XXXXXXXXXXXXXXXXX +XXXXX XXXXXX W ;| Status XXXX | Cond XXXX | ST(4) =XXXXXXXXXXXXXXXX =XXXX XXXXXX 8 ;S Tag XXXX | Comp X | ST(5) =XXXXXXXXXXXXXXXX =XXXX XXXXXX 7 ;T ---------------| Test X | ST(6) =XXXXXXXXXXXXXXXX =XXXX XXXXXX | ;A Stack Top X | Exam XXXXXX | ST(7) =XXXXXXXXXXXXXXXX =XXXX XXXXXX X ;T ------------------------------------------------------------------------ X ;E Except PX UX OX ZX DX IX Intr Mask PX UX OX ZX DX IX Ints XXXXXXXX X ;---------------------------------------------------------------------------- ; ; Compare: > < = ? ; Test: + - 0 ? ; Examine: +Unorm +NAN -Unorm -NAN +Norm +Infin -Norm -Infin +0 -0 ; +Dnorm -Dnorm Empty ; Precision: 24 53 64 ?? ; Rounding: near Up Down Trunc ; Infinity: Proj Affin ; Interrupts: Enabled Disabled ;========================================================================= ; Ver_Hi equ 1 ;ones version number Ver_Lo equ 10 ;tens version number HotKey equ 7e00h ;hot key, Alt-7 StartRow equ 0 ;screen row offset StartCol equ 0 ;screen column offset Rows equ 12 ;rows in display Cols equ 76 ;columns in display Atr_Bor equ 07h ;border attribute Atr_Mes equ 70h ;edge text attribute Atr_Lin equ 07h ;line attribute Atr_Tex equ 07h ;center text attribute Atr_Set equ 07h ;number and settings attribute Sig_Bits equ 57 ;number of significant bits in real ;number display ;================================================ ; Main program, execute shell after resetting ; interrupt 09H. ;================================================ ; .model TINY .code org 100h ;----------------- Program Entry point -------------------------- Entry: jmp Init ;go to initialization ;--- switch stack and set memory allocation Start: mov bx, offset Program_Stack ;new stack top mov sp, bx ;switch to stack mov cl, 4 shr bx, cl ;make paragraph inc bx ;account for extra test byte ptr Status, Status1 ;check if resident mode jnz Main1 mov ah, 4ah ;function int 21h ;execute ;--- save the interrupt data Main1: push bx push es mov ax, 3509h ;function and interrupt number int 21h mov word ptr Original09, bx ;save offset mov word ptr Original09+2, es ;save segment pop es pop bx ;--- load the new interrupt mov ax, 2509h ;function mov dx, offset Interrupt09 ;entry point offset int 21h ;execute test byte ptr Status, Status1 ;check if resident mode jnz Main3 ;--- initialize the EXEC parameter block and enter shell push es push ds mov Prog_Off, sp ;save stack offset mov Prog_Seg, ss ;save stack segment mov ax, 4b00h mov bx, offset Parameter_Blk ;pararmeter block location mov [bx+4], cs ;save the present segment mov dx, CmdLoc ;program name offset mov ds,cs:[2ch] ; segment int 21h cli mov sp, cs:Prog_Off ;restore stack offset mov ss, cs:Prog_Seg ;restore stack segment sti pop ds pop es ;--- show exit message sub al, al mov dx, offset Closemes ;normal termination message jnc Main2 mov al, 0ffh mov dx, offset Errormes ;error message Main2 : mov ah, 9 ;function int 21h ;show message ;--- finished push ax ;save return code mov ax, 2509h ;function lds dx, Original09 ;load original interrupt ; location int 21h ;execute pop ax mov ah, 4ch ;exit function int 21h ;execute ;--- resident mode, terminate and stay resident Main3 : mov ax, 3100h ;function and return code mov dx, bx ;paragraphs to save int 21h ;execute ;================================================ ; Control recieved through interrupt 09H. Interrupt09 proc far ;--- guard against reentering cmp cs:Active, 0 ; is show87 active? je Inter0 jmp cs:Original09 ; yes, pass to old handler Inter0: ;--- first call old handler pushf call cs:Original09 ;--- check if activation key is ready push ax ; save registers push bx mov ah, 01 ; non-destructive read int 16h jz Inter1 ; any characters there? cmp ax, HotKey ; check if activation key je Inter2 ; jump if so Inter1: pop bx ; restore registers pop ax iret ;;--- hot key was pressed Inter2: inc cs:Active ; flag active xor ah, ah ; read and clear int 16h ; get key function pop bx ; restore registers pop ax ;--- save stack Inter3 : mov cs:Stack_Seg, ss ;segment mov cs:Stack_Off, sp ;offset ;--- switch to local stack cli push cs pop ss ;set to local segment mov sp, offset Local_Stack ;set to offset sti ;--- save registers pushf push ax push bx push cx push dx push di push si push Bp push ds push es ;--- initialize push cs pop ds ;set data segment push cs pop es ;set other data segment cli fnsave State_Area ;save the 8087 state fwait ;synchronize sti cld ;normal direction call Video_Init ;initialize display data call Video_Cget ;get the cursor location mov CurLoc, dx ;save it ;--- save the screen area mov dh, StartRow ;first row mov di, offset Save_Area ;screen save area Inter4 : mov dl, StartCol ;first column Inter5 : call Video_Cset ;move cursor mov ah, 8 ;function mov bh, Video_Page ;get the page push di int 10h ;execute, get character pop di stosw ;store ah and al inc dl ;next column cmp dl, StartCol+Cols ;check if past end jb Inter5 ;loop back if not inc dh ;next row cmp dh, StartRow+Rows ;check if past end jb Inter4 ;loop back if not ;--- show main display mov bl, Atr_Set ;attribute mov cx, StartRow*256+StartCol ;upper left corner mov dx, ((StartRow+Rows-1)*256)+StartCol+Cols-1 ;lower right corner call Video_Cpag ;clear screen area mov si, offset Display1 ;main display string call Video_Wstr ;write to screen ;--- show stats call Display_State ;show state ;--- wait for key mov dx, ((StartRow+Rows-1)*256)+StartCol+Cols-1 ;lower right corner call Video_Cset ;move cursor there sub ah, ah ;function number int 16h ;get a key and wait ;--- restore the screen area mov dh, StartRow ;first row mov si, offset Save_Area ;screen save area Inter6 : mov dl, StartCol ;first column Inter7 : call Video_Cset ;move cursor lodsw ;load character ; and attribute mov bl, ah ;attribute mov ah, 9 ;function mov bh, Video_Page ;get the page mov cx, 1 ;count push si int 10h ;execute, get character pop si inc dl cmp dl, StartCol+Cols ;check if past end jb Inter7 ;loop back if not inc dh ;next row cmp dh, StartRow+Rows ;check if past end jb Inter6 ;loop back if not ;--- finished mov dx, CurLoc ;get cursor location call Video_Cset ;set it frstor State_Area ;restore state pop es pop ds pop bp pop si pop di pop dx pop cx pop bx pop ax popf ;--- restore original stack cli mov ss, cs:Stack_Seg ;segment mov sp, cs:Stack_Off ;offset sti ;--- return from interrupt mov cs:Active,0 ;Inactive iret endp ;Interrupt09 ;====================================================== ; Display the 8087 state. ;======================================================= Display_State proc near ;--- instruction pointer mov ax, State_Area+6 ;instruction pointer, lower 16 bits mov bx, State_Area+8 ; upper 4 bits mov cl, 12 shr bx, cl ;put the bits in the bottom mov cx, 5*256+16 ;display width and base mov dx, 1*256+11 ;display location offset call Display_Number ;display ;--- operand pointer mov ax, State_Area+10 ;operand pointer, lower 16 bits mov bx, State_Area+12 ; upper 4 bits push cx mov cl, 12 shr bx, cl ;put the bits in the bottom pop cx inc dh ;next row call Display_Number ;display ;--- op code mov ax, State_Area+8 ;get the op code and ax, 0000011111111111b ;mask out bits or ax, 1101100000000000b ;set implicit bits sub bx, bx ;clear high word mov ch, 4 ;new display width inc dh ;next row inc dl ;next column call Display_Number ;display ;--- control word mov ax, State_Area ;control word inc dh ;next row call Display_Number ;display ;--- status word mov ax, State_Area+2 ;status word inc dh ;next row call Display_Number ;display ;--- tag word mov ax, State_Area+4 ;tag word inc dh ;next row call Display_Number ;display ;--- stack top call Get_Stack ;get the stack top sub ah, ah add dx, 0203h ;add two to the rows and add ; three to the columns mov cx, 1*256+10 ;display width and base call Display_Number ;display ;--- precision mov bl, State_Area+1 ;high word of control and bl, 11b ;mask bits sub bh, bh mov cl, 2 ;width mov dx, 1*256+29 ;display location offset mov di, offset Dissta3b ;table call Display_Istr ;display string ;--- rounding mov bl, byte ptr State_Area+1 ;high word of control and bl, 1100b ;mask bits sub bh, bh shr bx, 1 shr bx, 1 mov cl, 5 ;width inc dh sub dl, 3 ;display location offset mov di, offset Dissta4b ;table call Display_Istr ;display string ;--- infinity mov bl, byte ptr State_Area+1 ;high word of control and bl, 10000b ;mask bit sub bh, bh mov cl, 4 shr bx, cl mov cl, 5 ;width inc dh ;next row mov di, offset Dissta5b ;table call Display_Istr ;display string ;--- condition codes mov al, byte ptr State_Area+3 ;high byte of status call Adjst_Codes ;adjust the condition codes sub bx, bx ;clear high word mov cx, 4*256+2 ;display width and base add dx, 0201h ;new location call Display_Number ;display ;--- comparison and test call Get_Comp ;get the index mov cl, 1 ;width add dx, 0103h ;location mov di, offset Dissta1b ;table call Display_Istr ;display string inc dh mov di, offset Dissta2b ;table call Display_Istr ;display string ;--- examine mov al, byte ptr State_Area+3 ;high byte of status inc dh sub dl, 5 ;location call Display_Exam ;display ;--- exception bit settings mov al, byte ptr State_Area+2 ;get the bits mov dx, 10*256+10 ;display offset call Display_Bits ;display ;--- mask bit settings mov al, byte ptr State_Area ;get the bits mov dx, 10*256+41 ;display offset call Display_Bits ;display ;--- interrupts mov ax, word ptr State_Area ;control word shl ax,1 ;shift bit to high byte and ah, 1b ;mask mov bl, ah sub bh, bh mov cl, -8 ;width mov dx, 10*256+66 ;display offset mov di, offset Dissta6b ;table call Display_Istr ;display string ;--- show stack data call Display_Stack ;show stack values ret ;--- data Dissta1a db '>',0, '<',0, '=',0, '?',0 Dissta1b dw offset Dissta1a dw offset Dissta1a+2 dw offset Dissta1a+4 dw offset Dissta1a+6 Dissta2a db '+',0, '-',0, '0',0, '?',0 Dissta2b dw offset Dissta2a dw offset Dissta2a+2 dw offset Dissta2a+4 dw offset Dissta2a+6 Dissta3a db '24',0, '??',0, '53',0, '64',0 Dissta3b dw offset Dissta3a dw offset Dissta3a+3 dw offset Dissta3a+6 dw offset Dissta3a+9 Dissta4a db 'Near',0, 'Up',0, 'Down',0, 'Trunc',0 Dissta4b dw offset Dissta4a dw offset Dissta4a+5 dw offset Dissta4a+8 dw offset Dissta4a+13 Dissta5a db 'Proj',0, 'Affin',0 Dissta5b dw offset Dissta5a dw offset Dissta5a+5 Dissta6a db 'Enabled',0, 'Disabled',0 Dissta6b dw offset Dissta6a dw offset Dissta6a+8 endp ;Display_State ;================================================ ; Display of the settings of six consecutive ; bits. ; ; In: al= bit pattern; dx= row and column display ; offset. ;================================================== ; Display_Bits proc near mov ah, al mov bh, 20h ;first bit to check mov cx, 6 ;bits to check add dx, StartRow*256+StartCol ;real screen location ;--- loop for each bit Disbit1 : mov al, '-' ;not set sign test ah, bh ;check if set jz Disbit2 mov al, '+' ;set sign Disbit2 : call Display_Char ;display character shr bh,1 ;shift bit to test add dl, 2 ;next location loop Disbit1 ret endp ;Display_Bits ;================================================ ; Display the stack values. ;================================================ Display_Stack proc near std mov bx, offset State_Area ;save area add bx, 14 ;skip to numbers mov cx, 8 ;8087 stack entries mov dh, StartRow+1 ;first display row ;=== display a number Disstk1 : push bx push cx fld TBYTE PTR [bx] ;load number ;--- get number type or set to empty push cx ;save stack number call Get_Stack ;get the stack top mov cl, al mov ax, word ptr State_Area+4 ;get the tag word shl cl,1 ;two bits for each tag ror ax, cl ;adjust so first tag is ; in low bits pop cx mov ch, 8 sub ch, cl shl ch, 1 ;bits to shift to put set ; tag low mov cl, ch shr ax, cl ;tag bits to lower bit ; locations 0 and 1 and ax, 11b ;mask bits ;--- check type cmp ax, 11b ;check if empty je Disstk2 fxam ;check number type fstsw Status87 ;store status cmp ax, 10b ;check if special je Disstk3 ;jump if so ;--- normal value call Display_Float ;display decimal number jmp short Disstk4 ;--- empty Disstk2 : mov Status87, 0ffffh ;set all bits ;--- special number Disstk3 : call Display_Hex ;display hexadecimal bit ; pattern ;--- finished with a single stack number Disstk4 : mov al, byte ptr Status87+1 ;high byte of status call Display_Exam ;display pop cx pop bx add bx, 10 ;next stack entry inc dh ;next row loop Disstk1 ;loop for each entry cld ret endp ;Display_Stack ;================================================ ; Display a decimal floating point number. ; ; In: ST(0)= number; dh= row. ; ; Out: dx= row and column one space after number. ;================================================== ; Display_Float proc near ;--- convert number and store mov ax, Sig_Bits ;number of significant bits call Flt2dec ;convert to decimal mov si, offset Number_Store ;storage for number fbstp Tbyte Ptr [si] ;save number string ;--- display the mantissa sign push ax ;save the exponent mov dl, StartCol+40 ;column add si, 9 ;goto last byte fwait ;let fbstp finish lodsb ;get the sign byte mov ah, '+' test al, 80h ;check if negative jz Disflt1 mov ah, '-' Disflt1 : mov al, ah ;sign call Display_Char ;display character ;--- first two digits and decimal point lodsb call Display_Bhi ;high digit push ax mov al, '.' ;decimal point call Display_Char ;write point pop ax call Display_Blo ;low digit ;--- remaining mantissa digits mov cx, 8 ;remaining number of ; packed bytes Disflt2 : lodsb call Display_Bhi ;high digit call Display_Blo ;low digit loop Disflt2 ;--- exponent sign pop ax inc dl ;skip to exponent location mov cl, '+' ;plus add ax, 17 ;adjust for decimal point jns Disflt3 ;jump if not minus mov cl, '-' ;minus neg ax Disflt3 : push ax mov al, cl call Display_Char ;display pop ax ;--- exponent sub bx, bx ;clear high word mov cx, 5*256+10 ;load width and base call Display_Number ;display add dl, 6 ;position cursor at end ret ;================================================= ; Display a high packed BCD digit. ; ; In: al= packed BCD digits; bl= attribute. ;================================================== Display_Bhi proc near push ax shr al, 1 shr al, 1 shr al, 1 shr al, 1 ;shift the high bits add al, '0' ;convert to decimal digit call Display_Char ;write point pop ax ret endp ;Display_Bhi ;================================================= ; Display a low packed BCD digit. ; ; In: al= packed BCD digits; bl= attribute. ;================================================== ; Display_Blo proc near push ax and al, 0fh ;mask relevant bits add al, '0' ;convert to decimal digit call Display_Char ;write point pop ax ret endp ;Display_Blo endp ;Display_Float ;================================================ ; Display the bit pattern of a floating point ; number. ; ; In: ST(0)= number; dh= row. ; ; Out: dx= row and column one space after number. ;================================================== ; Display_Hex proc near fstp Dishex1 ;store number fwait ;wait just in case mov al, '=' ;starting character mov dl, byte ptr StartCol+43 ;column call Display_Char ;display mov cx, 8 ;bytes lea si, Dishex1+7 ;last byte of mantissa call Display_Byts ;display mov al, '=' ;starting character add dl, 2 ;column call Display_Char ;display mov cx, 2 ;bytes lea si, Dishex1+9 ;last byte of exponent call Display_Byts ;display inc dl ;next column ret ;--- storage for the tempory real number Dishex1 label Tbyte dt ? ; ;================================================ ; Display backwards bytes. ; ; In: si= starting location; cx= bytes. ;================================================= ; Display_Byts proc near pushf std sub ah, ah ;clear high byte sub bx, bx ;clear high word Disbys1 : lodsb ;load byte push cx push si mov cx, 2*256+16 ;format call Display_Number ;display add dl, 2 ;next location pop si pop cx loop Disbys1 ;loop for each byte popf ret endp ;Display_Byts endp ;Display_Hex ;================================================ ; Display an FXAM result. ; ; In: al= high byte of 8087 status; dx= row and ; column location. ;================================================= ; Display_Exam proc near call Adjst_Codes ;adjust the condition codes mov bx, ax mov cl, 6 ;width mov di, offset Disexm1b ;table call Display_Istr ;display string ret ;--- data Disexm1a db '+Unorm',0, '+NAN',0, '-Unorm',0, '-NAN',0 db '+Norm',0, '+Infin',0, '-Norm',0, '-Infin',0 db '+0',0, '-0',0, '+Dnorm',0, '-Dnorm',0, 'Empty',0 Disexm1b dw offset Disexm1a dw offset Disexm1a+7 dw offset Disexm1a+12 dw offset Disexm1a+19 dw offset Disexm1a+24 dw offset Disexm1a+30 dw offset Disexm1a+37 dw offset Disexm1a+43 dw offset Disexm1a+50 dw offset Disexm1a+70 dw offset Disexm1a+53 dw offset Disexm1a+70 dw offset Disexm1a+56 dw offset Disexm1a+70 dw offset Disexm1a+63 dw offset Disexm1a+70 endp ;Display_Exam ;================================================ ; Get the stack top number. ; ; Out: al= stack number. ;================================================= ; Get_Stack proc near mov al, byte ptr State_Area+3 ;get the high byte ; of the status word and al, 00111000b ;mask out stack shr al, 1 shr al, 1 shr al, 1 ;adjust ret endp ;Get_Stack ;================================================ ; Adjust the condition codes to consecutive bits. ; ; In: al= high byte of status. ; Out: ax= condition codes in consecutive, least ; significant bit locations. ;================================================= ; Adjst_Codes proc near mov ah, al and al, 00000111b ;mask C2 to C0 bits and ah, 01000000b ;mask C3 bit shr ah , 1 shr ah , 1 shr ah , 1 ;shift bit over or al, ah ;combine sub ah, ah ret endp ;Adjst_Codes ;================================================ ; Get an index for the comparison and test ; instructions. Based on the condition codes. ; ; Out: bx= index. ;================================================== ; Get_Comp proc near sub bx, bx mov al, State_Area+3 ;high byte of state and al, 01000101b ;mask C3 C2 and C0 cmp al, 00000000b ;check if 0 0 0 je Getcom1 inc bx cmp al, 00000001b ;check if 0 0 1 je Getcom1 inc bx cmp al, 01000000b ;check if 1 0 0 je Getcom1 inc bx Getcom1: ret endp ;Get_Comp ;================================================ ; Display a single character. ; ; In: al= character; dx= location. ;================================================= ; Display_Char proc near mov bl, Atr_Set ;attribute call Video_Cset ;set cursor location call Video_Wchr ;write character inc dl ;next column ret endp ;Display_Char ;================================================ ; Display a zero padded number to a location. ; ; In: bx:ax= number; cl= number base; ch= the ; display width; dx= location. ;================================================= ; Display_Number proc near push ax push cx push dx add dx, StartRow*256+StartCol ;real screen location call Video_Cset ;move cursor push cx sub ch, ch mov dx, bx ;high word mov di, offset Number_Store ;place to store call Convert_Num ;convert to string pop cx mov al, '0' ;pad character mov cl, ch sub ch, ch mov si, di call Video_Wstrr ;display number pop dx pop cx pop ax ret endp ;Display_Number ;================================================ ; Given an index and a table, displays a space ; padded string to a location. ; ; In: bx= index; di= table offset; cl= width, if ; negative, the string is right justified instead ; of left; dx= location. ;================================================= ; Display_Istr proc near push ax push bx push cx push dx push si ;--- locate cursor add dx, StartRow*256+StartCol ;real screen location call Video_Cset ;move cursor ;--- display string mov al, ' ' ;pad with spaces shl bx, 1 ; ;two bytes for offset sub ch, ch mov si, [di+bx] ;get the string location cmp cl, 0 jg Disist1 neg cl ;absolute value call Video_Wstrl ;display, left justified jmp short Disist2 Disist1: call Video_Wstrr ;display, right justified Disist2: pop si pop dx pop cx pop bx pop ax ret endp ;Display_Istr ;================================================ ; External files. include Video1.inc include Video2.inc include Convert1.inc include Convert2.inc ;================================================ ; Data. ;--- program status Status1 equ 01h ;execute in memory ; resident mode Status db 0 ;--- original interrupt 09H Original09 label Dword dw ? ;offset dw ? ;segment ;--- shell parameter block Parameter_Blk label Word dw 0 ;use default environment dw offset CmdTail ;command tail dw ? ;present segment dw -1 ; dw -1 ; dw -1 ;-- no FCB'S dw -1 ; CmdTail db 0, 13 ;--- saved stack addresses Prog_Off dw ? ;-- save area through EXEC function Prog_Seg dw ? ; Stack_Off dw ? ;-- save area for alternate int 09 Stack_Seg dw ? ; ;--- other data CmdLoc dw ? ;offset of command processor in environment CurLoc dw ? ;saved cursor location Active dw ? ;popup window is active ;--- main display string Display1 label Byte db FrmAtr, Atr_Bor, FrmLoc, StartRow, StartCol, 219 db FrmHor, 223, Cols-2, 219, FrmLoc, StartRow+1, StartCol db FrmVer, 219, Rows-2, FrmLoc, StartRow+1, StartCol+Cols-1 db FrmVer, 219, Rows-2, FrmLoc, StartRow+Rows-1 db StartCol, 219, FrmHor, 220, Cols-2, 219 db FrmAtr, Atr_Lin, FrmLoc, StartRow+9, StartCol+2 db FrmHor, 196, 72, FrmLoc, StartRow+1, StartCol+32 db FrmVer, 179, 8, 193 db FrmAtr db Atr_Mes db FrmLoc, StartRow+1, StartCol, '8' db FrmLoc, StartRow+2, StartCol, '0' db FrmLoc, StartRow+3, StartCol, '8' db FrmLoc, StartRow+4, StartCol, '7' db FrmLoc, StartRow+6, StartCol, 'S' db FrmLoc, StartRow+7, StartCol, 'T' db FrmLoc, StartRow+8, StartCol, 'A' db FrmLoc, StartRow+9, StartCol, 'T' db FrmLoc, StartRow+10, StartCol, 'E' db FrmLoc, StartRow+1, StartCol+Cols-1, 'S' db FrmLoc, StartRow+2, StartCol+Cols-1, 'H' db FrmLoc, StartRow+3, StartCol+Cols-1, 'O' db FrmLoc, StartRow+4, StartCol+Cols-1, 'W' db FrmLoc, StartRow+5, StartCol+Cols-1, '8' db FrmLoc, StartRow+6, StartCol+Cols-1, '7' db FrmLoc, StartRow+8, StartCol+Cols-1, Ver_Hi MOD 10+'0' ; db FrmLoc, StartRow+9, StartCol+Cols-1, Ver_Lo/10+'0' db FrmLoc, StartRow+10, StartCol+Cols-1, Ver_Lo MOD 10+'0' ; db FrmAtr, Atr_Tex db FrmLoc, StartRow+1, StartCol+2, 'Ins Ptr' db FrmLoc, StartRow+2, StartCol+2, 'Opr Ptr' db FrmLoc, StartRow+3, StartCol+2, 'Op Code' db FrmLoc, StartRow+4, StartCol+2, 'Control' db FrmLoc, StartRow+5, StartCol+2, 'Status' db FrmLoc, StartRow+6, StartCol+2, 'Tag' db FrmLoc, StartRow+8, StartCol+2, 'Stack Top' db FrmLoc, StartRow+1, StartCol+19, 'Prec' db FrmLoc, StartRow+2, StartCol+19, 'Round' db FrmLoc, StartRow+3, StartCol+19, 'Infin' db FrmLoc, StartRow+5, StartCol+19, 'Cond' db FrmLoc, StartRow+6, StartCol+19, 'Comp' db FrmLoc, StartRow+7, StartCol+19, 'Test' db FrmLoc, StartRow+8, StartCol+19, 'Exam' db FrmLoc, StartRow+1, StartCol+34, 'ST(0)' db FrmLoc, StartRow+2, StartCol+34, 'ST(1)' db FrmLoc, StartRow+3, StartCol+34, 'ST(2)' db FrmLoc, StartRow+4, StartCol+34, 'ST(3)' db FrmLoc, StartRow+5, StartCol+34, 'ST(4)' db FrmLoc, StartRow+6, StartCol+34, 'ST(5)' db FrmLoc, StartRow+7, StartCol+34, 'ST(6)' db FrmLoc, StartRow+8, StartCol+34, 'ST(7)' db FrmLoc, StartRow+10, StartCol+2, 'Except' db FrmLoc, StartRow+10, StartCol+9, FrmStr dw offset Display2 db FrmLoc, StartRow+10, StartCol+30, 'Intr Mask' db FrmLoc, StartRow+10, StartCol+40, FrmStr dw offset Display2 db FrmLoc, StartRow+10, StartCol+61, 'Ints' db FrmAtr, Atr_Set db 0 Display2 db 'P U O Z D I', 0 ;--- exit message Closemes db 13,10,'SHOW87 is removed from memory.',13,10,'$' Errormes db 13,10,'Error: Could not install SHOW87', 13,10,'$' ;================================================ ; Uninitialized data. Save_Area label Byte ;screen data org $+(Rows * Cols * 2) State_Area label UNKNOWN ;area to save the 8087 state org $+94 Status87 label Word ;8087 status storage for ; checking numbers org $+2 Number_Store label Byte ;storage for decimal ; number strings org $+11 org $+100h Local_Stack label Byte ;local stack for state display org $+100h Program_Stack label Byte ;main program stack org offset Save_Area ;fix location ;================================================ ; Transient code. Exists in unitialized data ; area, must be executed before the data area is ; used. ;--- display opening message Init : mov dx, offset Openmes ;message mov ah, 9 ;function int 21h ;display ;--- check for 80x87 installed call Installed8087 ;check for 80x87 cmp ax, 1 ;ax=1 if 80x87 installed je Init0 ; else 80x87 is NOT installed mov dx, offset No8087mes mov ah, 9 ;display message indicating int 21h ;that no 80x87 is installed jmp short Init8 ;--- find command processor Init0 : push es mov cx, 8 ;string length sub di, di ;starting offset of environment mov es, cs:[2ch] ;environment segment ;--- loop for each string in the environment Init1 : cmp byte ptr es:[di], 0 ;check if end of environment je Init8 mov cx, 8 ;string length mov si, offset Comspec ;string location repe cmpsb ;compare bytes je Init3 ;jump if found Init2 : cmp byte ptr es:[di-1], 0 ;see if stopped on end ; of string je Init1 inc di ;next byte jmp Init2 Init3 : mov CmdLoc, di ;save location pop es ;--- set resident flag mov si, 80h ;command tail lodsb ;get the length or al, al ;check if none jz Init6 mov cl, al sub ch, ch ;put count in cx ;--- loop through characters in command tail Init4 : lodsb ;load next byte cmp al, '/' ;check if switch je Init7 ;jump if so Init5 : loop Init4 ;otherwise loop back Init6: jmp Start ;--- found slash Init7: dec cx ;reduce count jz Init6 ;jump if no more bytes lodsb ;load command character sub al, 'a'-'A' ;convert to upper-case cmp al, 'R' ;check if R jne Init5 ;if not, go back to loop xor Status, Status1 ;set (or clear) flag jmp Start ;--- could not find COMSPEC= Init8: mov dx, offset Errormes ;error message mov ah, 9 ;function int 21h ;show message mov ax, 4cffh ;exit function int 21h ;execute ;========================================================= ;returns true if an 8087 or 80x87 coprocessor is installed ;========================================================= Installed8087 proc near int 11h ;get BIOS equipment flags and ax, 2 ;bit is ON if 80x87 is present shr ax, 1 ret Installed8087 endp ;--- transient data Openmes db 13,10 db 'SHOW87, Version ' db Ver_Hi MOD 10+'0', '.', Ver_Lo/10+'0', Ver_Lo MOD 10+'0','$' No8087mes db 13,10 db 'No numeric processor detected',13,10,'$' ;--- command environment string Comspec db 'COMSPEC=' END Entry