The IBM Personal Computer MACRO Assembler 01-13-85 PAGE 1-1 1 comment * parint.com (c) 1984 by david g hunter. 2 this program may be freely copi ed but not be sold for profit. 3 parint.com detects parity error s, logs them on the printer if 4 possible, beeps, and returns to program execution. the system 5 does not halt when this program is resident. parity error 6 checking is terminated after th e first error is detected. The 7 error message includes the time of the event. If the printer 8 is not available, the errors ar e logged to the screen. 9 * 10 ;****************addresses of interrupt handlers ******************* 11 0000 book segment at 0h ;this is where the interrupt address book is 12 0008 org 2h*4 13 0008 int_2 label dword ;address of nmi handler 14 0008 book ends 15 16 ;***************beginning of parint ins tructions ******************* 17 0000 cseg segment 18 assume cs:cseg 19 0100 org 100h 20 0100 E9 024A R start: jmp newvec ;install new nm i handler in ram 21 ;***************nmi handler************ ***************************** 22 0103 newint proc near ;new interrupt handler 23 assume ds:cseg, es:cseg 24 0103 FB sti ;this flag was cleared when interrupt was issued 25 0104 E9 0199 R jmp go ;jump over more data 26 ;**********************data************ **************** 27 0107 90 getout: nop 28 0108 EA instruc db 0EAh ;this is the ju mp-immediate instruction! 29 ;it jumps to th e address stored in oldint. 30 0109 00 00 00 00 oldint dd ;address of old interrupt 2 routine 31 010D 0004 device1 dw 0004 ;printer 32 010F 0001 device2 dw 0001 ;standard outpu  The IBM Personal Computer MACRO Assembler 01-13-85 PAGE 1-2 t device 33 0111 0D 0A 50 61 72 69 par1 db 0Dh,0Ah,"Parity Error: Main Board ",07h,0Dh,0Ah 34 74 79 20 45 72 72 35 6F 72 3A 20 4D 61 36 69 6E 20 42 6F 61 37 72 64 20 20 20 20 38 20 07 0D 0A 39 0133 0D 0A 50 61 72 69 par2 db 0Dh,0Ah,"Parity Error: Expansion Board",07h,0Dh,0Ah 40 74 79 20 45 72 72 41 6F 72 3A 20 45 78 42 70 61 6E 73 69 6F 43 6E 20 42 6F 61 72 44 64 07 0D 0A 45 0155 20 20 20 20 54 49 time db " TIME: " 46 4D 45 3A 20 20 47 0160 3030 hour dw "00" 48 0162 3A db ":" 49 0163 3030 min dw "00" 50 0165 20 20 20 20 20 20 db " ",0Dh, 0Ah 51 20 20 20 20 20 20 52 20 20 20 20 0D 0A 53 0177 50 41 52 49 54 59 paroff db "PARITY CHECKING NOW DI SABLED ",0Dh,0Ah,0Ah 54 20 43 48 45 43 4B 55 49 4E 47 20 4E 4F 56 57 20 44 49 53 41 57 42 4C 45 44 20 20 58 20 0D 0A 0A 59 0199 51 go: push cx 60 019A 1E push ds 61 019B 9C pushf 62 019C 52 push dx 63 019D 53 push bx 64 019E 50 push ax 65 019F 9C pushf 66 01A0 B0 00 mov al,00h 67 01A2 E6 A0 out 0A0h, al 68 01A4 33 C9 xor cx,cx 69 01A6 E4 62 in al, 62h 70 ; find origin of nmi 71 01A8 A8 40 test al, 40h 72 01AA 74 06 jz mother 73 01AC BA 0133 R mov dx, offset par2 ;if bit 6 set, error is on expansion bd 74 01AF EB 16 90 jmp out 75 01B2 A8 80 mother: test al,80h 76 01B4 74 06 jz other 77 01B6 BA 0111 R mov dx, offset par1 ;if bit 7 set, error is on main board 78 01B9 EB 0C 90 jmp out  The IBM Personal Computer MACRO Assembler 01-13-85 PAGE 1-3 79 01BC 81 C9 0001 other: or cx, 1h 80 01C0 B0 80 mov al, 80h 81 01C2 E6 A0 out 0A0h, al 82 01C4 EB 23 90 jmp noprt ;don't print me ssage if no parity error 83 ; print error message and exit 84 01C7 8C C8 out: mov ax,cs 85 01C9 8E D8 mov ds,ax 86 01CB E8 021A R call whatime ;get time of er ror 87 01CE 8B 1E 010D R mov bx, device1 88 01D2 83 FB 04 cmp bx,0004 89 01D5 75 03 jne f1 90 01D7 E8 01FC R call testprt 91 01DA E8 0210 R f1: call print 92 01DD BA 0155 R mov dx, offset time ;"time of error" message 93 01E0 E8 0210 R call print 94 01E3 BA 0177 R mov dx, offset paroff 95 01E6 E8 0210 R call print 96 01E9 9D noprt: popf 97 01EA 58 pop ax 98 01EB 5B pop bx 99 01EC 5A pop dx 100 01ED 9D popf 101 01EE 1F pop ds 102 01EF F7 C1 0001 test cx, 1h 103 01F3 75 02 jnz oth 104 01F5 59 pop cx 105 01F6 CF iret 106 ; if no parity error, give contro l to pre-existing nmi handler 107 ; this is done by restoring ds and jump ing to the instruction that 108 ; specifies the address of the old inte rrupt routine. This unusual 109 ; exit is necessary because otherwise, once ds was restored, the 110 ; address of the old interrupt routine would not be accessible. 111 01F7 FA oth: cli 112 01F8 59 pop cx 113 01F9 E9 0107 R jmp getout 114 01FC newint endp 115 ;********************subroutines******* *****************8 116 01FC testprt proc near 117 01FC 52 push dx 118 01FD 50 push ax 119 01FE 33 D2 xor dx,dx 120 0200 B4 02 mov ah,2 121 0202 CD 17 int 17h 122 0204 F6 C4 29 test ah,00101001b  The IBM Personal Computer MACRO Assembler 01-13-85 PAGE 1-4 123 0207 74 04 jz aok 124 0209 8B 1E 010F R mov bx, device2 125 020D 58 aok: pop ax 126 020E 5A pop dx 127 020F C3 ret 128 0210 testprt endp 129 0210 print proc near 130 0210 51 push cx 131 0211 B9 0022 mov cx,34 ;34 characters to print 132 0214 B4 40 mov ah,40h ;dos function c all 133 0216 CD 21 int 21h 134 0218 59 pop cx 135 0219 C3 ret 136 021A print endp 137 021A whatime proc near 138 021A 51 push cx 139 021B 52 push dx 140 021C B4 2C mov ah,2Ch 141 021E CD 21 int 21h 142 0220 8A C5 mov al,ch 143 0222 E8 0241 R call convt 144 0225 C7 06 0160 R 3030 mov hour,"00" 145 022B 01 06 0160 R add hour,ax 146 022F 8A C1 mov al,cl 147 0231 E8 0241 R call convt ;do same for mi nutes (0-59) 148 0234 C7 06 0163 R 3030 mov min,"00" 149 023A 01 06 0163 R add min,ax 150 023E 5A pop dx 151 023F 59 pop cx 152 0240 C3 ret 153 0241 whatime endp 154 0241 convt proc near ;convert number (100) to ascii. number is in al 155 0241 32 E4 xor ah,ah 156 0243 51 push cx 157 0244 B1 0A mov cl,10 158 0246 F6 F1 div cl 159 0248 59 pop cx 160 0249 C3 little: ret 161 024A convt endp 162 ;*******************install nmi handler *********************8 163 024A newvec proc near 164 024A EB 45 90 jmp past 165 024D 0D 0A 50 41 52 49 loaded db 0Dh,0Ah,"PARITY ERROR I NTERCEPTOR V2.00 BY DAVID HUNTER IS NOW" 166 54 59 20 45 52 52 167 4F 52 20 49 4E 54 168 45 52 43 45 50 54 169 4F 52 20 56 32 2E  The IBM Personal Computer MACRO Assembler 01-13-85 PAGE 1-5 170 30 30 20 42 59 20 171 44 41 56 49 44 20 172 48 55 4E 54 45 52 173 20 49 53 20 4E 4F 174 57 175 0284 20 49 4E 53 54 41 DB " INSTALLED",0DH,0AH,"$ " 176 4C 4C 45 44 0D 0A 177 24 178 0291 BA 024D R past: mov dx, offset loaded 179 0294 B4 00 mov ah,0 180 0296 CD 21 int 21h 181 assume ds:book 182 0298 1E push ds 183 0299 B8 ---- R mov ax,book 184 029C 8E D8 mov ds,ax 185 029E B0 00 mov al, 00h 186 02A0 E6 A0 out 0A0h, al 187 02A2 A1 0008 R mov ax,int_2 188 02A5 2E: A3 0109 R mov oldint,ax 189 02A9 A1 000A R mov ax,int_2[2] 190 02AC 2E: A3 010B R mov oldint[2],ax 191 02B0 C7 06 0008 R 0103 R mov int_2, offset newint 192 02B6 8C 0E 000A R mov int_2[2],cs 193 02BA B0 80 mov al, 80h 194 02BC E6 A0 out 0A0h, al 195 02BE BA 024A R mov dx, offset newvec 196 02C1 CD 27 int 27h 197 02C3 newvec endp 198 02C3 cseg ends 199 end start  The IBM Personal Computer MACRO Assembler 01-13-85 PAGE Symbols -1 Segments and groups: N a m e Size align combine class BOOK . . . . . . . . . . . . . . 0008 AT 0000 CSEG . . . . . . . . . . . . . . 02C3 PARA NONE Symbols: N a m e Type Value Attr AOK. . . . . . . . . . . . . . . L NEAR 020D CSEG CONVT. . . . . . . . . . . . . . N PROC 0241 CSEG Length =0009 DEVICE1. . . . . . . . . . . . . L WORD 010D CSEG DEVICE2. . . . . . . . . . . . . L WORD 010F CSEG F1 . . . . . . . . . . . . . . . L NEAR 01DA CSEG GETOUT . . . . . . . . . . . . . L NEAR 0107 CSEG GO . . . . . . . . . . . . . . . L NEAR 0199 CSEG HOUR . . . . . . . . . . . . . . L WORD 0160 CSEG INSTRUC. . . . . . . . . . . . . L BYTE 0108 CSEG INT_2. . . . . . . . . . . . . . L DWORD 0008 BOOK LITTLE . . . . . . . . . . . . . L NEAR 0249 CSEG LOADED . . . . . . . . . . . . . L BYTE 024D CSEG MIN. . . . . . . . . . . . . . . L WORD 0163 CSEG MOTHER . . . . . . . . . . . . . L NEAR 01B2 CSEG NEWINT . . . . . . . . . . . . . N PROC 0103 CSEG Length =00F9 NEWVEC . . . . . . . . . . . . . N PROC 024A CSEG Length =0079 NOPRT. . . . . . . . . . . . . . L NEAR 01E9 CSEG OLDINT . . . . . . . . . . . . . L DWORD 0109 CSEG OTH. . . . . . . . . . . . . . . L NEAR 01F7 CSEG OTHER. . . . . . . . . . . . . . L NEAR 01BC CSEG OUT. . . . . . . . . . . . . . . L NEAR 01C7 CSEG PAR1 . . . . . . . . . . . . . . L BYTE 0111 CSEG PAR2 . . . . . . . . . . . . . . L BYTE 0133 CSEG PAROFF . . . . . . . . . . . . . L BYTE 0177 CSEG PAST . . . . . . . . . . . . . . L NEAR 0291 CSEG PRINT. . . . . . . . . . . . . . N PROC 0210 CSEG Length =000A START. . . . . . . . . . . . . . L NEAR 0100 CSEG TESTPRT. . . . . . . . . . . . . N PROC 01FC CSEG Length =0014 TIME . . . . . . . . . . . . . . L BYTE 0155 CSEG WHATIME. . . . . . . . . . . . . N PROC 021A CSEG Length =0027 Warning Severe Errors Errors 0 0