title POP-CAL - popup calendar for 1583 - 9999 AD. comment ~ Use Alt-C, to pop up and terminate calendar generator. Use left/right cursor keys to change months. Use Up/Down cursor keys to change years. ~ cseg segment assume cs:cseg ;----------------------------------------------------------------------------- ppfdata struc ;Variable data is stored in PPF area. rom16h dw ?,? ;Holds old Interrupt 16h BIOS vector. savss dw ? ;Holds caller's stack segment savsp dw ? ;Holds caller's stack pointer video_seg dw ? ;Holds base segment of video buffer mnth db ? ;calendar's month year dw ? ;calendar's year weekday db ? ;1st day of month 0=Sun,,,,6=Sat left dw ? ;Offset to left edge of calendar, row 0 hilite db ? ;Calendar display attribute. busy db ? ;Busy flag, for our stack crt_mode db ? ;Holds current crt mode crt_cols dw ? ;Number of columns on screen status_port dw ? ;video card status port address ppfdata ends org 100h-status_port v ppfdata <> ;Locate ppfdata and assign prefix "v". ;----------------------------------------------------------------------------- org 100h begin: jmp Install ;Initialize calendar; go resident. db "Copyright 1986 Ziff-Davis Publishing Co.",1Ah days db 'SunMonTueWedThrFriSat' months db 'JanFebMarAprMayJunJulAugSepOctNovDec' numdays db 31,28,31,30,31,30,31,31,30,31,30,31 ;Jan-Dec days/month bios dw 40h ;Points to BIOS data segment scan_code dw 2e00h ;(Alt)(C) scan code to start/stop program. ;---------------- Intercept keystroke reading -------------------------------- int16h: sti ;Turn interrupts back on. cmp ah,0 ;See if was request for an actual key. je come_back ;If so, we'll check it first. skip_us:jmp dword ptr v.rom16h ;Otherwise, let go straight to caller. come_back: cmp v.busy,0 ;Is calendar routine busy? jne skip_us ;If so, pass all keys along. getkey: pushf ;Else, call BIOS keyboard routine, call dword ptr v.rom16h ;so it will return the key to us. cmp ax,scan_code ;Is scan code correct? je now_busy ;If so, go to work. iret ;Else just pass on key to caller. now_busy: mov v.busy,1 ;Set busy flag, to protect our stack. mov v.savss,ss ;Save caller's stack segment. mov v.savsp,sp ;save caller's stack pointer. mov sp,cs cli ;Avoid interrupt right now. mov ss,sp ;Reset stack to our code segment. mov sp,offset v.rom16h ;Start our stack below ROM16 addr. sti push ax push bx push cx push dx push bp push si ;Save all user's registers. push di push ds push es call begin_calendars ;Go do the calendars. pop es ;When finished,... pop ds pop di pop si pop bp ;Restore all user's registers pop dx pop cx pop bx pop ax cli mov ss,v.savss ;restore old stack mov sp,v.savsp sti mov ah,0 ;Reset AH to BIOS key read function. mov v.busy,0 ;Allow reuse of calendar stack. jmp getkey ;Go get new key from BIOS. ;--------------- Read keys input. Process calendars. ---------------------- begin_calendars: push cs push cs pop ds ;Set DS and ES to our code segment. pop es cld ;Set for standard "up" direction. assume ds:cseg ;Let Assembler use DS addressing, now. call wndo ;Save Screen data. Put old calendar on it. jmp showcal ;Go fill in calendar, in case none made yet. nxtcal: mov v.mnth,dh ;Store new month value. mov v.year,cx ;Store new year. showcal:call fill ;Format and display new calendar. input: mov ah,0 ;Wait for key stroke. int 16h cmp ax,scan_code ;Another (Alt)(C)? jne getdate ;If not, initialize CX (year) and DH (month). exit: call wndo ;Restore original screen data and ret ; go restore caller's stack... all done. getdate:mov dh,v.mnth ;Load calendar month into DH. mov cx,v.year ;Load calendar year into CX. trylft: cmp ah,75 ;Was key a left arrow? jne tryrgt ;If not, go see if was a right arrow. dec dh ; If a left arrow, reduce month by 1. jns nxtcal ; When pass Jan, switch mov dh,11 ; to Dec of prior year. dec cx ; Reduce year by one. jmp chkloyr ; Go check that its still in range. tryrgt: cmp ah,77 ;Right arrow? (increase month) jne tryup ;If not, see if an Up arrow. inc dh ; Was right arrow, so increase month. cmp dh,11 ; See if past December. jng nxtcal ; If not, go make the calendar. mov dh,0 ; If was, reset month to January inc cx ; and move up to next year. jmp chkhiyr ; Then insure year is still in range. tryup: cmp ah,72 ;Up arrow? (increase year) jne trydwn ;If not, see if was a down key. inc cx ; If Up, increase year by 1. chkhiyr:cmp cx,10000 ; Year can only be 4 digits. jge input ; Ignore key, if date goes out of range. jmp nxtcal ; Otherwise go make new calendar. trydwn: cmp ah,80 ;Down arrow? (decrease year) jne input ;If not, ignore key and go get new one. dec cx ; Down key reduces year by 1. chkloyr:cmp cx,1582 ;Calendar calculations only good for 11/1582 jle input ; on, so ignore key, if year now < 1583. jmp nxtcal ; Otherwise, go make new calendar. ;------------------ Fill in the new calendar ------------------------------ fill: call firstday ;Calculate weekday of 1st of month. mov es,v.video_seg ;Point ES to write to screen. mov al,v.mnth ;Put current month into AL. cbw ;Zeros out AH. mov cx,3 ;Zero out CH. Put 3 in CL. mul cl ;AX = # bytes to current month's name mov si,offset months; from start of "months". add si,ax ;SI=offset to month's name mov di,v.crt_cols ;Put screen width (# columns) in DI. add di,v.left ;Move to left edge, second row. add di,22 ;Move on to center month in the row. movname:lodsb ;Load character from month's name. call writebyte ;Output char of month's name to screen. loop movname ;Do three times, since cx=3. add di,2 ;Skip a space, after the month's name. mov ax,v.year ;Load year into AX. mov bl,100 ;Will use to split year into centuries div bl ; portion and remaining years in century. mov bh,1 ;Set flag, so will retain leading zero. call unpack ;Display the centuries portion of year. mov al,ah ;Put remainder in al. call unpack ;Display remaining 2 digits in year. setdi: mov ax,v.crt_cols ;Load current screen width. mov bl,4 ;Mult by # rows to skip. mul bl ;Calculate offset to 4th row of calendar. add ax,4 ;Skip in 2 columns on that row. mov di,v.left ;Set to offset of top left corner of calendar. add di,ax ;Move to location of 1st date on screen. mov dl,v.weekday ;Retrieve week day of 1st of cal's month. mov cl,dl ;Store as count of days to blank in 1st week. mov dh,6 ;DH = # weeks left to fill in. jcxz start_current_month ;If Sunday, CX = 0 and no blanking needed. blnkrw1:call blank2 ;Blank out 1st part of 1st week. loop blnkrw1 start_current_month: mov cl,7 ;Number of days to display in 1st week sub cl,dl ; = 7 - weekday of 1st day. mov bl,v.mnth ;Set index for days-per-month array. xor bh,bh ;Set flag to suppress leading zeros. mov dl,numdays[bx] ;Get # days in current month. mov al,1 ;Set AL to 1st day of month. showdays: call unpack ;Format and display the date value. inc al ;Increment to next day. add di,4 ;Skip to next day position. dec dl ;Reduce # days left in month. jz blnkrst ;If last day, blank rest of the 6 weeks. loop showdays ;Otherwise continue displaying dates in week. call nxtweek ;When reach end of a week, space to next one. jmp showdays ; and continue on new row of calendar. blnkrw4:call blank2 ;Blank out remaining days in week. blnkrst:loop blnkrw4 ;Blank to end of current week. call nxtweek ;Relocate DI to 1st day of next week. jnz blnkrw4 ;If not past last week, go blank week out. push cs ;When all done, restore ES to CS. pop es ret ;Return to keyboard reading routine. ;---------------------- Move DI to 1st date in next week --------------------- nxtweek:add di,v.left ;Move to left edge of next row of calendar. add di,4 ;Move in an additional 2 columns. mov cl,7 ;Restart week count. dec dh ;Reduce weeks left in calendar. ret ;---------------------- Compute weekday of 1st day of month ------------------ firstday: mov si,v.year ;Hold year in SI, of quick access. mov numdays[1],28 ;Assume this isn't a leap year. test si,3 ;Now see if year divisible by 4. jnz getday ;If not, was actually not a leap year. feb29: mov numdays[1],29 ;Else was leap year with 29 days. getday: mov bx,6 ;BX=Saturday,(weekday of 1/1/1583) mov ax,si ;Calendar year to AX. sub ax,1583 ;Calc. # years since our base year. add bx,ax ;Calendar advances 1 weekday per ; year unless leap years intervene. add ax,2 ;Adj diff, so even #, if the calendar mov cx,4 ; year was year after a leap year. cwd ;Zero out DX. div cx ;Calculate # leap years before this. add bx,ax ;Add 1 day to week, for each leap yr. cmp si,1700 ;Things work normally 'til 1700, which jl cnvrt ;not a leap year, per Gregorian cal. mov ax,si ;Year back to AX, again. sub ax,1600 ;Get # years since 1600. mov cl,100 cwd ;Convert to number of centuries. div cx cmp dx,0 ;If remainder=0 this is centennial yr. jne deduct test ax,3 ;If century is evenly divisible by jz decax ; 400, it is also still a leap year. mov numdays[1],28 ;Other centenial years have 28 days. decax: dec ax ;If centenial yr, sub 1 from centuries deduct: sub bx,ax ;Subtract 1 weekday per century. cwd mov cl,4 div cx ;Calculate centuries mod 400. add bx,ax ;Add back 1 day per 400 years. cnvrt: mov si,offset numdays ;Add in the days per month, this yr. xor ah,ah ;First clear hi byte of accumulator mov cl,v.mnth ;Load cx with month counter jcxz final ;If January, are ready for final calc. addmnth:lodsb ;Get low byte into accumulator. add bx,ax ;Add to days count. loop addmnth ;Continue until prior months added in. final: mov ax,bx ;AX=# days advanced since 1/1/1583. cwd ;Clear out DX. mov cl,7 ;Find # full weeks since 1583. div cx ;DL=weekday of 1st of calendar's month mov v.weekday,dl ;Save results of this work. ret ;-------------- Convert binary # in AL to ASCII and output to ES:DI ---------- unpack: push ax ;(AL should binary # from 0-99.) push bx aam ;Divide al by 10. add ax,3030h ;Convert digits to ASCII. cmp ah,30h ;See if 10's digit was a zero. jne putnum ;If not, go output it to screen. cmp bh,1 ;If BH=1, leading zero is ok, so je putnum ; go write it. Otherwise, replace mov ah,20h ; leading zero with a blank. putnum: mov bl,al ;Need to write high order digit first, mov al,ah ; so save low digit and move hi into AL. call writebyte ;Output 10's digit to screen. mov al,bl ;Put 1's digit back in AL. call writebyte ;Write 1's digit. pop bx ;Restore BX. pop ax ;Retrieve old binary value. ret ;All done. ;------------------- Blank out 2 digit calendar date field. Update DI. ------ blank2: mov al,20h ;Put a blank in AL call writebyte ;Write a blank over 1st digit. call writebyte ;Write a blank over 2nd digit. add di,4 ;Skip 2 spaces, to next date. ret ;------------------- Write char AL on screen at ES:DI. Update DI. ------------ writebyte: push dx ;Save DX. mov dx,v.status_port ;Reset to video status port address. mov ah,al ;Move character to AH, for now. on1: in al,dx ;Wait until not doing a test al,1 ; horizontal scan retrace. jnz on1 cli on2: in al,dx ;Now wait until next horizontal test al,1 ; retrace begins, so KNOW will have jz on2 ; entire retrace time period to work. mov al,ah ;Retrieve character from AH. stosb ;Store character on screen. sti inc di ;Skip over attribute byte on screen. pop dx ;Restore old DX value. ret ;---------------------- Switch memory field with screen data ----------------- wndo: call getprms ;Get current video parms mov dx,v.status_port ;Point DX to Status Port. sub dx,2 ;Back up to control port. mov es,bios ;Point to ROM BIOS data segment mov bh,es:[65h] ;Get current setting of video card. mov al,bh ;Move to AL, for output, after reset. and al,0f7h ;Turn off video enable bit only. out dx,al ;Turn off screen. mov si,offset data_strt ;Point to calendar data in memory. mov di,v.left ;Set DI=upper left corner of calendar. mov es,v.video_seg ;Set ES to video buffer segment. mov bl,11 ;11 rows in the calendar. nxtlin: mov cx,30 ;There are 30 words per calendar row. getchr: mov ax,es:[di] ;Get next word from screen buffer. movsw ;Move data word to screen. mov [si-2],ax ;Store screen character in our data. loop getchr ;Continue across row. add di,v.left ;Move to start of next calendar row. dec bl ;Reduce rows-to-go count. jnz nxtlin ;Do next row, if more to go. mov al,bh ;Restore video setting to original out dx,al ; and turn on screen again. push cs pop es ;Restore ES to our code segment. ret ;------------------- Get video display parameters ---------------------------- getprms:push es mov es,bios ;Point ES to BIOS data segment. mov ax,es:[4ah] ;Put current column width. shl ax,1 ;Multiply by 2, for attribute bytes. mov v.crt_cols,ax ;Store in our data, for easy access. sub al,30*2 ;Back off from right side, by width of mov v.left,ax ;calendar. Equals offset to left edge. mov ax,es:[63h] ;Get base address of video card. add ax,6 ;Calculate status port address and mov v.status_port,ax ; save for checking horiz scans. mov v.hilite,70h ;Black on white background. mov bl,es:[49h] ;Get video mode into BL. cmp bl,7 ;In Monochrome video mode? mov ax,0B000h ;Monochrome buffer seg at 0B000h. je setseg ;If monochrome, go store video seg. mov ax,0B800h ;If graphics card, video seg=0B800h. test bl,1 ;1,3 are color text on graphics card. jz setseg mov v.hilite,1fh ;Use bright white on blue, if color. setseg: mov v.video_seg,ax ;Store video_segment value pop es ;Restore Es. ret ;Done. ;------------------ Create calendar form and become resident. --------------- Install:call getprms ;Call, to get correct color attribute. mov di,offset data_strt ;Point to end of our code segment. mov ah,v.hilite ;Set attribute byte in AH. mov al,20h ;Will store blanks in calendar area. mov cx,11*30 ;11 rows of 30 columns each. rep stosw ;Blank out calendar work area push di ;Save end of calendar offset. mov si,offset days ;Now store day's names in calendar. mov bl,7 ;Set names-to-go counter to 7. mov di,offset data_strt ;Point to start of calendar add di,3*30*2+4 ;Skip in 3 rows + 2 columns. movday: mov cx,3 ;There are 3 chars per name. movchr: movsb ;Transfer character into calendar. inc di ;Skip over attribute byte. loop movchr ;Continue for three characters. inc di inc di ;Add 2 to DI, to skip space. dec bl ;Reduce names-to-go count. jnz movday ;Continue until all stored. mov ah,2ah ;Get current date from DOS. int 21h dec dh ;Convert months,so Jan=0, etc. mov v.mnth,dh ;Save month and year values. mov v.year,cx go_resident: xor ax,ax mov es,ax ;Set ES to 0. mov ax,es:[16h*4] mov v.rom16h,ax ;Store rom interrupt 16h address. mov ax,es:[16h*4+2] mov v.rom16h+2,ax mov ax,offset int16h cli mov es:[16h*4],ax ;Point Interrupt 16 to our code. mov es:[16h*4+2],cs sti pop dx ;Retrieve address of end of data. int 27h ;Now become resident. ;----------------- Calendar data area -------------------------------- data_strt equ this word cseg ends end begin