þa‹RþwQþ mU9þhý oþ nSystem-wide NAME Validate CODE SEGMENT PUBLIC 'CODE' ASSUME CS:CODE,DS:CODE,ES:CODE,SS:CODE PUBLIC ValidateProgram ;============================================================================== ; ; ValidateProgram: Check for ROM to make sure this is not a copy ; ; This procedure banks in each of the 8 rom banks looking for valid ; ROM headers. If a valid header is found the program compares the Optional ; ROM Name with the string listed below. The procedure returns if the two ; match. If they don't match the procedure goes to the next ROM slot. If ; all ROM slots do not match the "key" string then the procedure prints out ; an "illegal copy" message and aborts the program. ; ; NOTE - the Optional ROM Name is placed in the ROM using the ROM Build ; program "ROM" options menu. Both this string and the KeyString listed ; below should match exactly, including the case (upper or lower) of the ; characters used. To change the KeyString just replace the characters in ; the quotes below to the KeyString to be used. Up to 50 characters are ; allowed. Then use the new keystring for the Optional ROM Name when creating ; the PROM with ROMBuild. ; ;============================================================================== KeyString DB 'Program X',0 InvalidMsg DB 13,10,'Unauthorized program duplicate detected.',13,10 DB 'Program aborted.',13,10,'$' ValidateProgram PROC FAR PUSH AX ; save the registers PUSH BX PUSH CX PUSH DX PUSH ES PUSH SI CLI ; turn off interrupts - this is very ; important and must not be omited MOV DX,403H ; set for NON- 32K EPROM Mode MOV AL,0 OUT DX,AL MOV DX,405H ; set to enable ROMs MOV AL,1 OUT DX,AL MOV CX,8 ; set loop counter for 8 slots SearchLoop: PUSH CX ; save the loop counter MOV AL,CL ; use loop counter to select bank DEC CL ; adjust so zero relative MOV DX,440H ; get port for first 32K of ROM area OUT DX,AL ; bank slot into this area INC DX ; get port for second 32K of ROM area OUT DX,AL ; bank slot into this area INC DX ; get port for third 32K of ROM area OUT DX,AL ; bank slot into this area INC DX ; get port for last 32K of ROM area OUT DX,AL ; bank slot into this area MOV AX,9FF0H ; get ROM header segment value MOV ES,AX ; set up extra segment MOV BX,0 ; point to first byte CMP WORD PTR ES:[BX],0BB66H ; is there a valid rom header ? JNE NextSlot ; no - then jump ADD BX,8EH ; point to start of Optional ROM Name MOV SI,OFFSET KeyString ; point to key string CheckChar: MOV AL,CS:[SI] ; get a key string character CMP AL,0 ; is it the end of the string ? JE KeyStringFound ; yes - key must match then - so jump CMP ES:[BX],AL ; does it match optional rom name char ? JNE NextSlot ; no - doesn't match then - so jump INC BX ; point to next rom name char INC SI ; point to next key string char JMP CheckChar ; go check next character NextSlot: POP CX ; restore the loop counter LOOP SearchLoop ; go check next slot EndProgram: ; no match was found at this point MOV DX,405H ; set to disable roms MOV AL,0 OUT DX,AL ; disable roms STI ; restore the interrupts PUSH DS ; save the data segment PUSH CS ; set data segment to invalid message POP DS MOV DX,OFFSET IllegalMsg ; get offset of the message MOV AH,9 ; set for MS-DOS string output INT 21H ; go output the string POP DS ; restore the data segment MOV AH,04CH ; set to end the program MOV AL,0 ; set return code INT 21H ; abort program KeyStringFound: ; at this point the string has been found POP CX MOV DX,405H ; set to disable roms MOV AL,0 OUT DX,AL ; disable the ROMs STI ; reenable interrupts POP SI ; restore the registers POP ES POP DX POP CX POP BX POP AX RET ; return to calling program ValidateProgram ENDP CODE ENDS END