;A Program for the TI86 for password protecting your calc! (v3.0)
;by TI SoftWare 5/20/1998
;Please visit our website at:
;http://www.geocities.com/siliconvalley/peaks/1062/   Thanx!!!
;By the way, the password is 'TISW'
;YES!!! -- No bugs!!!!
;The ON-pressed bug of previous versions, which was when
;you turned on the TI86 and entered the correct password after shutting it
;down from the home screen (NOT a shell), you would get ERROR 06
;BREAK and the standard menu  :(
;This bug no longer occurs since Calculator Guardian v3.0 now
;'clears' the ON-pressed 'flag'!!!

#include "asm86.h"
#include "ti86asm.inc"

.org _asm_exec_ram


;*********Shell Description**********

	nop
	jp Start

.dw $0000
.dw ShellDescription

ShellDescription:
	.db "Calculator Guardian v3.0",0

;********End Description*************

Start:
	call    _runindicoff
	ld      a, $01                                     ;Many thanks to FangSoft for their shutdown
	out     ($03), a                                   ;routine from Blank Screen v.05 - TI86 ASM!
	HALT
	ld      a, $0b
	out     ($03), a
	jr  Next

Next:
	call    _clrLCD                 ;clear the LCD screen
	set     3, (IY+5)               ;change text to black-on-white
	ld      de, $0003
	ld      (CURSOR_ROW), de        ;set cursor at 0,0 - top left of screen
	ld      hl, versioninfo         ;display "CalcGuard 3.0"
	call    _puts
	ld      de, $0005
	ld     (CURSOR_ROW), de         ;move the cursor to row 5, column 1
	ld      hl, author
	call    _puts                   ;display "By TI Software"
	res     3, (IY+5)               ;Change text back to white-on-black
	ld de, $0702
	ld (CURSOR_ROW), de             ;move cursor to the middle of the screen
	ld b,$04                        ;we need only 4 key presses
				
PWEnter:
	push bc
	call GET_KEY                    ;Get a keypress
	pop bc                          ;take bc off of stack
	cp K_NOKEY                      ;no key pressed, so...
	jr z, PWEnter                   ;try again!
	push af                         ;save the key that was pressed
	ld hl,asterisk
	call _puts                      ;display one asterisk
	djnz PWEnter                    ;repeat the loop until b is equal to 0 (zero)

PWCheck:
	pop af                          
	cp K_3                          
	jr nz, WrongPW3         
	pop af                          
	cp K_6                          
	jr nz, WrongPW2         
	pop af
	cp K_RIGHTPAR                          
	jr nz, WrongPW1
	pop af
	cp K_MINUS                          
	jr nz,Start
	jr FinishUp       ;correct password - leave program!!!

			  
WrongPW3:                 ;reverse all pushes that were done!
	pop af
WrongPW2:
	pop af
WrongPW1:
	pop af
	jr Start

FinishUp:
	call _clrLCD
	res   4,(iy+$09)
	ret


;String Constants
;------------------------

versioninfo:
	.db "    CalcGuard 3.0    ",0

author: 
	.db "  By TISoftware '98  ",0

blanks:
	.db "                     ",0

asterisk:
	.db "*",0

.END
END