!!!Typo bug virus
not really a virus, but a funny background program that creates random typos on "A" and "E" :)
{{{
00010 .LI OFF
00020 ******************************
00030 * *
00040 * PROGRAMM:VERTIPP 0.1 *
00050 * AUTOR :CARSTEN STROTMANN *
00060 * DATUM :21.04.90 *
00070 * VERSION :0.1 *
00080 * FUER :DUMME SCHERZE *
00090 * *
00100 ******************************
00110 ;
00120 CH = $2FC
00130 VKEYBD = $208
00140 CASINI = $2
00150 BOOT = $9
00160 RTCLOK2 = $14
00170 PORTB = $D301
00180 KBCODE = $D209
00190 CH1 = $02F2
00200 KEYDEL = $02F1
00210 KEYDIS = $026D
00220 SSFLAG = $02FF
00230 HLPFLG = $02DC
00240 ATTRACT = $4D
00250 KRPDEL = $02D9
00260 SRTIMR = $022B
00270 SDMCTL = $022F
00280 DMASAV = $02DD
00290 KEYINT = $FC19
00300 RANDOM = $D20A
00310 ;
00320 .OR $600
00330 ; .OF "D:AUTOS.COM"
00340 ;
00350 INIT
00360 LDA VKEYBD
00370 STA CASINI
00380 LDA VKEYBD+1
00390 STA CASINI+1
00400 LDA #KI
00410 STA VKEYBD
00420 LDA /KI
00430 STA VKEYBD+1
00440 LDA #INIT
00450 STA CASINI
00460 LDA /INIT
00470 STA CASINI+1
00480 LDA BOOT
00490 ORA #2
00500 STA BOOT
00510 RTS
00520 ;
00530 KEYBD
00540 PHA
00550 LDA RANDOM
00560 CMP #$D0
00570 BCC END
00580 LDA CH
00590 CMP #42
00600 BNE .1
00610 LDA #46
00620 STA CH
00630 .1 CMP #106
00640 BNE .2
00650 LDA #110
00660 STA CH
00670 .2 CMP #63
00680 BNE .3
00690 DEC CH
00700 .3 CMP #127
00710 BNE .4
00720 DEC CH
00730 .4 CMP #54
00740 BNE END
00750 LDA #158
00760 STA CH
00770 END PLA
00780 RTI
00790 ------------------------------
00800 KI TXA
00810 PHA
00820 TYA
00830 PHA
00840 LDY PORTB
00850 LDA KBCODE
00860 STA CH
00870 CMP CH1
00880 BNE .1
00890 LDX KEYDEL
00900 BNE .9
00910 .1 LDX KEYDIS
00920 CMP #$83
00930 BNE .2
00940 TXA
00950 EOR #$FF
00960 STA KEYDIS
00970 BNE .3
00980 TYA
00990 ORA #$04
01000 BNE .4
01010 .3 TYA
01020 AND #$FB
01030 .4 TAY
01040 BCS .5
01050 .2 TXA
01060 BNE .6
01070 LDA KBCODE
01080 TAX
01090 CMP #$9F
01100 BNE .7
01110 LDA SSFLAG
01120 EOR #$FF
01130 STA SSFLAG
01140 BCS .5
01150 .7 AND #$3F
01160 STX HLPFLG
01170 BEQ .5
01180 STX CH
01190 STX CH1
01200 .5 LDA #$03
01210 STA KEYDEL
01220 LDA #$00
01230 STA ATTRACT
01240 .9 LDA KRPDEL
01250 STA SRTIMR
01260 LDA SDMCTL
01270 BNE .6
01280 LDA DMASAV
01290 STA SDMCTL
01300 .6 STY PORTB
01310 PLA
01320 TAY
01330 PLA
01340 TAX
01350 PLA
01360 JMP KEYBD
01370 ------------------------------
01380 .OR $02E0
01390 .DA INIT
01400 ------------------------------
}}}