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Assembly Source File | 1986-12-25 | 15.5 KB | 570 lines

Title 'Wolfware Sample Program', 'Resident Time Display' ;===============================================; ; Resident Time Display Version 1.10 ; ; ; ; A RAM resident utility which, if active, ; ; constantly displays the time in the the ; ; upper right corner. Once the utility is ; ; installed, the time is activated or ; ; deactivated with Alt-1 (hold down the Alt ; ; key and type 1 on the numeric keypad, then ; ; release the Alt key). The program is ; ; initially non-activated when first ; ; installed. Once assembled, to install, just ; ; type: ; ; ; ; RTIME ; ; ; ; The time is updated about three times a ; ; second, in the backround of whatever program ; ; is presently being executed. The time ; ; display overwrites whatever is on the screen ; ; at that location. The display can only be ; ; activated or deactivated when the foreground ; ; program does keyboard I/O via interrupt 16H. ; ; This utility uses about 1065 bytes of ; ; memory. ; ; ; ; For simplicity, the program assumes that ; ; there are 65535 ticks in an hour, though ; ; there are actually 65543. This means that ; ; the displayed time is 8 ticks fast for each ; ; hour past midnight. The most it is off ; ; occurs just before midnight, when it is ; ; 8 * 23 = 184 ticks, or about 10 seconds fast. ; ; As result of this the time actually runs to ; ; about 24:00:10 before switching to 00:00:00. ; ; ; ; This program may not be compatible with ; ; other RAM resident type programs. ; ;===============================================; Proc Far Jmp Install ;skip to installation routine ;===============================================; ; Equates ; ;===============================================; True Equ -1 ;true flag False Equ 0 ;false flag ;----- display location, location of first character of 8 byte string Row Equ 1 ;row, 1 to 25 Column Equ 73 ;column, 1 to 80 ;----- execution parameters Key Equ 0001h ;int 16H key code to activate, Alt-1 Attribute Equ 70h ;display attribute, reverse video Count_Set Equ 6 ;wait count, updated 18.2/COUNT_SET = 3/sec ;----- BIOS data, at segment 0 Equip_Flag Equ 0410h ;equipment word Screen_Col Equ 044ah ;CRT columns ;----- interrupt location, at segement 0 Keyboard Equ 58h ;keyboard fetch, interrupt 16 Timer_Tick Equ 70h ;timer tick vector location, interrupt 1C ;----- clock information Timer_Low Equ 046ch ;low word of timer, at segment 0 Timer_High Equ 046eh ;high word of timer, at segment 0 Counts_Sec Equ 18 ;counts in second Counts_Min Equ 1092 ;counts in minute Counts_Hor Equ 0ffffh ;counts in hour ;----- local stack size, stack just has to handle ;----- local routines and any hardware interrupts Stack Equ 20 + 20 ;size ;===============================================; ; Int16 ; ; Alternate interrupt 16H (keyboard I/O) to ; ; handle normal function calls while ; ; intercepting display activation/deactivation ; ; commands. Check for command only if read key ; ; or get keyboard status (functions 0 and 1). ; ;===============================================; Int16 Proc Far Sti ;interrupts on Pushf ;save entry flags ;----- read next key Or Ah, Ah ;check if read key Jnz Nonkey ;jump if not I16get Seg Cs ;code segment Call Old_Int16 ;keyboard interrupt Cmp Ax, Key ;check scan code Je Subkey ;jump if activate key Iret ;----- activation key on read Subkey Call Toggle_Act ;toggle present setting Sub Sp, 2 ;simulate flags for interrupt call Sub Ah, Ah ;read next key function Jmps I16get ;try again ;----- keyboard status Nonkey Cmp Ah, 1 ;check if keyboard status Jne Nonstat ;jump if not Popf ;restore entry flags Pushf ;flags for interrupt call Seg Cs ;code segment Call Old_Int16 ;keyboard interrupt Pushf Jnz I16chksk ;jump if key in buffer Popf Ret 2 ;throw away flags in stack on return I16chksk Cmp Ax, Key ;check scan code Je I16fact ;jump if activate key Popf Ret 2 ;throw away flags in stack on return ;----- activation key on status I16fact Sub Ah, Ah ;get key function Sub Sp, 2 ;simulate flags for interrupt call Seg Cs ;code segment Call Old_Int16 ;keyboard interrupt, get key Call Toggle_Act ;toggle present setting Mov Ah, 1 ;status function Jmps Nonkey ;try again, flags still on stack ;----- keyboard shift status or unknown function Nonstat Seg Cs ;code segment Call Old_Int16 ;keyboard interrupt, (flags on stack) Iret Endp ;Int16 ;===============================================; ; Toggle_Act ; ; Toggle active setting and reset screen info. ; ; Clears time display (sets to dashes). ; ;===============================================; Toggle_Act Proc Near Seg Cs Cmp Activated, True ;check if on Je Actoff ;jump if so, turn off ;----- activate Seg Cs Mov Activated, True ;activate Seg Cs Mov Counter, Count_Set ;reset counter Jmps Screenres ;----- deactivate Actoff Seg Cs Mov Activated, False ;activate off ;----- reset screen information and clear display ;----- switch to local stack Screenres Seg Cs Mov Stack_Seg, Ss ;save stack segment Seg Cs Mov Temp, Cs Seg Cs Mov Ss, Temp ;new stack segment Seg Cs Mov Stack_Off, Sp ;save stack pointer Seg Cs Mov Sp, Local_Stk ;new stack ;----- save all registers Push Ax Push Bx Push Cx Push Dx Push Di Push Si Push Ds Push Es Cld ;forward direction ;----- set screen information Sub Ax, Ax Mov Ds, Ax ;segement 0 Mov Bx, [Screen_Col] ;screen columns Mov Ax, 0b800h ;graphics segment Mov Dx, [Equip_Flag] ;get equipment flag And Dx, 30h ;mask CRT bits Cmp Dx, 30h ;check if BW card Jne Notbw ;jump if not Mov Ax, 0b000h ;BW segement Notbw Mov Dx, Cs Mov Ds, Dx Mov Es, Dx ;set data segment registers Mov Screen_Seg, Ax ;save segment ;----- calculate screen offset Mov Ax, Bx Sub Dx, Dx Mul Ax, Time_Row ;row offset Add Ax, Time_Col ;add for columns Shl Ax ;times two, account for attribute bytes Mov Screen_Off, Ax ;save ;----- clear time display (set numbers to dashes) Mov Ax, 2d2dh ;dashes to clear time and date Cli ;interrupts off while display Mov Di, Offset Tdisplay;dislay line Stosw ;hours Inc Di Stosw ;minutes Inc Di Stosw ;seconds Call Display ;display new string Sti ;interrupts back on ;----- restore registers Pop Es Pop Ds Pop Si Pop Di Pop Dx Pop Cx Pop Bx Pop Ax ;----- restore stack Seg Cs Mov Sp, Stack_Off ;stack pointer Seg Cs Mov Ss, Stack_Seg ;stack segment Ret Endp ;Toggle_Act ;===============================================; ; Int1c ; ; Alternate interrupt 1CH (timer tick). ; ; Executed every timer tick (about 18.2 times ; ; a second). ; ; ; ; One out of COUNT_SET cycles the time is ; ; displayed to its predetermined location, so ; ; the time is actually updated 18.2/COUNT_SET ; ; times per second. ; ; ; ; Each interrupt calls the original timer tick ; ; interrupt for the benefit of any other ; ; routines that were using it. ; ;===============================================; Int1c Proc Near Cli ;interrupts off ;----- check if activated Seg Cs Cmp Activated, True ;check if activated Je Redischk ;jump if so Exit Pushf ;flags for interrupt call Seg Cs Call Old_Int1c ;call original interrupt Iret Redischk Seg Cs Dec Counter ;decrement counter Jnz Exit ;jump if not zero ;----- redisplay time ;----- switch to internal stack Seg Cs Mov Activated, False ;deactivate Seg Cs Mov Stack_Seg, Ss ;save stack segment Seg Cs Mov Temp, Cs Seg Cs Mov Ss, Temp ;new stack segment Seg Cs Mov Stack_Off, Sp ;save stack pointer Seg Cs Mov Sp, Local_Stk ;new stack ;----- save all registers Push Ax Push Bx Push Cx Push Dx Push Di Push Si Push Ds Push Es Cld ;forward direction ;----- get time Sub Ax, Ax Mov Ds, Ax ;segment 0 Mov Dx,[Timer_High] ;timer high Mov Ax,[Timer_Low] ;timer low ;----- set time Mov Bx, Cs Mov Ds, Bx Mov Es, Bx ;set segment registers Mov Counter, Count_Set ;reset counter Mov Di, Offset Tdisplay ;start of time display string Mov Bx, Counts_Hor ;counts/hour Div Ax, Bx ;divide Call Number_Con ;convert to ASCII and store Inc Di ;skip colon Mov Ax, Dx ;remainder is new dividend Sub Dx, Dx Mov Bx, Counts_Min ;counts/minute Div Ax, Bx ;divide Call Number_Con ;convert to ASCII and store Inc Di ;skip colon Mov Ax, Dx ;remainder is new dividend Sub Dx, Dx Mov Bx, Counts_Sec ;counts/second Div Ax, Bx ;divide Call Number_Con ;convert to ASCII and store Call Display ;display string to screen ;----- restore registers Pop Es Pop Ds Pop Si Pop Di Pop Dx Pop Cx Pop Bx Pop Ax ;----- restore stack Seg Cs Mov Sp, Stack_Off ;restore stack pointer Seg Cs Mov Ss, Stack_Seg ;restore stack segment Seg Cs Mov Activated, True ;reactivate Jmp Exit ;exit routine Endp ;Int1c ;===============================================; ; Number_Con ; ; Convert number in AL to two digit ASCII ; ; string and store result to DI. Number must ; ; be in range 0 to 99. DI returns pointing to ; ; byte after new string. ; ;===============================================; Number_Con Proc Near Shl Al Sub Ah, Ah ;AX gets relative offset Add Ax, Offset Numbers ;absolute offset Mov Si, Ax Movsw ;move word (two byte digits) Ret ;----- data, 00 to 99 Numbers Label Byte Db '00010203040506070809' Db '10111213141516171819' Db '20212223242526272829' Db '30313233343536373839' Db '40414243444546474849' Db '50515253545556575859' Db '60616263646566676869' Db '70717273747576777879' Db '80818283848586878889' Db '90919293949596979899' Endp ;Number_Con ;===============================================; ; Display ; ; Display the time string to the screen by ; ; writing it directly to the screen buffer. ; ;===============================================; Display Proc Near Mov Ah, Attribute ;display attribute Mov Cx, Offset Tdisplay_End - Offset Tdisplay ;length Mov Di, Screen_Off ;offset into screen Mov Si, Offset Tdisplay ;start of time string Mov Es, Screen_Seg ;segment of screen ;----- move string to screen buffer Disloop Lodsb ;load character Stosw ;store character and attribute Loop Disloop ;loop CX times Ret Endp ;Display ;===============================================; ; Data ; ;===============================================; Activated Db False ;activation status, initially off Counter Db ? ;execution counter, set when activated Time_Row Dw Row - 1 ;display row Time_Col Dw Column - 1 ;display column Stack_Off Dw ? ;storage for stack offset Stack_Seg Dw ? ;storage for stack segment Local_Stk Dw Offset End + Stack ;local stack top Screen_Off Dw ? ;screen offset Screen_Seg Dw ? ;screen segment Temp Dw ? ;temporary storage ;----- display string Tdisplay Label Byte ;start of string Db '--:--:--' Tdisplay_End Label Byte ;end of string (to calculate length) ;----- original interrupts Old_Int16 Label Dword Dw ? ;offset Dw ? ;segment Old_Int1c Label Dword Dw ? ;offset Dw ? ;segment End Label Byte ;end of code and data, start of stack space ;===============================================; ; Install ; ; Install the alternate interrupts. ; ;===============================================; Install Proc Near ;----- install new interrupt vectors Mov Ax, Offset Int16 ;keyboard offset Mov Bx, Cs ;present segement Mov Cx, Offset Int1c ;timer offset Mov Dx, Cs ;present segement ;----- get and save old interrupts Mov Ax, 3516h ;function and interrupt 16h Int 21h ;execute Mov Word Old_Int16, Bx ;offset Mov Word Old_Int16+2, Es ;segment Mov Ax, 351ch ;function and interrupt 1ch Int 21h ;execute Mov Word Old_Int1c, Bx ;offset Mov Word Old_Int1c+2, Es ;segment ;----- set new interrupts Mov Ax, 2516h ;function and interrupt 16h Mov Dx, Offset Int16 ;keyboard offset Int 21h ;execute Mov Ax, 251ch ;function and interrupt 1ch Mov Dx, Offset Int1c ;timer offset Int 21h ;execute (and it's off!) ;----- display message Mov Dx, Offset Installm ;message location Mov Ah, 9 ;print string function Int 21h ;execute ;----- finish up Mov Dx, Local_Stk ;end of interrupt, top of local stack Mov Cl, 4 Shr Dx, Cl ;paragraph form Inc Dx ;allow for fraction of paragraph Mov Ax, 3100h ;exit function (stay resident) Int 21h ;execute ;----- message Installm Db 10 Db '/-------------------------------------------\', 13, 10 Db '| Resident time display utility installed |', 13, 10 Db '|----------------- Ver 1.10 ----------------|', 13, 10 Db '| press ALT-1 to activate/deactivate |', 13, 10 Db '\-------------------------------------------/', 13, 10,'$' Endp ;Install Endp ;main program