; In-Depth Guitar v2.0 Key Generator
; By CrackZ (24/02/99).

; Use tasm /zi idg2.asm and then tlink /v idg2
; to generate idg2.exe.

; Simplistic scheme.
; Uppercase user name, add together all letter values, omit the spaces, 
; multiply result by 88D8h (35072 dec), then insert hyphens xxx-xxxx-xx.

.MODEL SMALL
.STACK 100h
.386

.DATA

input   DB 1Eh,0 ; Max 30 for name length
prompt  DB 'Input your Registration Name (min. 1 letter): ','$'
done	DB 'Your Registration No. is: ','$'
lf      DB 0ah,0dh,'$'
logo    DB 0ah,0dh, '------------------------------------',0ah,0dh
	DB          ' In-Depth Guitar v2.0 Key Generator ',0ah,0dh
	DB	    ' By CrackZ (24/02/99)               ',0ah,0dh
	DB          '------------------------------------',0ah,0dh
	DB 0ah,0dh,'$'

.CODE

START:	MOV AX,@DATA
	MOV DS,AX
	MOV ES,AX
	LEA EDX,[logo]
	MOV AH,09h
	INT 21h		;Display Logo.
	LEA EDX,[prompt]
	MOV AH,09h
	INT 21h		;Prompt.
	LEA EDX,[input]
 	MOV AH,0Ah
	INT 21h		;Get registration name.
	LEA EDI,input+2
        MOVZX EBX, BYTE PTR [EDI-1] ;Name length in EBX.
	CMP BX,1h	;Check its at least 1.
	JB endprg	;Too short, gracefully exit.
	JMP inits	;Else do calculation routine.

inits:	XOR AX,AX
	XOR CX,CX	;Clear some registers.
	PUSH BX		;And push the namelength on the stack.

uppercasename:
	MOVZX ECX, BYTE PTR [EDI]	;Name pointer.
	CALL toupper			;UPPERCASE.
	ADD EAX,ECX			;Add to EAX.
	MOV BYTE PTR [EDI],CL
	INC DI				;Shift store.
	DEC BX
	JNZ uppercasename
	
docalc:	IMUL EAX,088D8h
	MOV CX,0Ah			;Move CX to 10 for output routine.
	POP BX				;Name length.
	SUB DI,BX			;Reset DI.
	XOR BX,BX			;Clear BX.

out0:	XOR EDX,EDX
	DIV ECX
	ADD EDX,30h
	PUSH EDX
	INC EBX
	TEST EAX,EAX
	JNZ out0

out1:	POP EDX				;Get character from the stack.
	MOV BYTE PTR [EDI+EAX],DL
	INC EAX
	CMP AX,3h
	JZ addhyphen
	CMP AX,7h
	JZ addhyphen
	JMP out2

out2:	TEST EBX,EBX
   	DEC EBX				;Decrement counter.
	JNZ out1
	CALL fixups
	SUB DI,2h
	JMP final

;----------Functions Section----------

addhyphen:
	MOV BYTE PTR [EDI+EAX], 2Dh	;Add hyphen.
	INC DI				;Now increment the store.
	JMP out2

fixups:	CMP AX,9h
	JGE fixend1
	JMP fixend2

fixend1:
	MOV BYTE PTR [EDI+EAX],'$'	;End char.
	RET	

fixend2:
	MOV CX,AX			;Store actual length in CX.
	MOV BX,9h
	SUB BX,CX			;BX holds how many to add.

fix2loop:
	MOV BYTE PTR [EAX+EDI],30h	;Add 0's as required.
	INC AX
	DEC BX
	TEST BX,BX
	JNZ fix2loop
	MOV BYTE PTR [EDI+EAX],'$'
	RET

toupper:
	CMP CL,20h
	JZ toupspace
	CMP CL,61h
	JL toupreturn
	CMP CL,7Ah
	JG toupreturn
	SUB CL,20h
	RET

toupreturn:
	RET	

toupspace:	
	XOR CX,CX	
	RET

final:	LEA EDX,[lf]
	MOV AH,09h
	INT 21h				;Linefeed.
	LEA EDX,[done]
	MOV AH,09h
	INT 21h	
	LEA EDX,[EDI]
	MOV AH,09h
	INT 21h

endprg:	LEA EDX,[lf]
	MOV AH,09h
	INT 21h
	MOV AX,4C00h
	INT 21h

END START