Re: A86: String input again

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Re: A86: String input again


This is pretty much the routine that someone posted.  I fixed a few
capitalization errors.  Can someone tell me what is wrong with this, or
comment it a little more thoroughly?  It crashes the calc pretty good.

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

.org _asm_exec_ram

	set shiftALock, (IY+shiftflags)		;turn on AlphaLock
	ld hl, string				;load address of string
keyloop:
	call _getkey				;get keypress
	cp kEnter
	jp z, key_done				;if enter was pressed
	cp kSpace				;is it space?
	jp z, key_space				;if it is a space
	push af					;preserve the keycode in A
	sub $1C					;k0
	jp m, keyloop				;it's not a usefull key if negative
	pop af					;recall the keycode
	push af					;and save it again
	sub $26					;k9 +1
	jp m, key_number			;if neg, assumed to be a number key
	pop af
	push af
	sub $28					;kCapA
	jp m, keyloop				;it's not a usefull key if negative
	pop af	
	push af
	sub $42					;kCapZ +1
	jp m, key_capletter			;if negative, then assume capital letter
	pop af
	sub $5C					;kz +1
	jp m, key_lowletter			;if neg, assume lower case letter
	jp keyloop				;must be a useless key at this point
key_space:
	ld a, Lspace				;char code for space
	ld (hl), a				;put into storage string at HL
	inc hl					;forward pointer to next spot in string
	call _vputmap				;display a space at current pen position
	jp keyloop				;get next letter or number
key_number:
	pop af					;we had a PUSH, we must have a POP
	add a, 12				;keycode-->char code
	ld (hl), a				;store it to the string
	inc hl					;increment string pointer
	call _vputmap				;display the number
	jp keyloop				;get next character
key_capletter:
	pop af					;we had a PUSH, must have a POP
	add a, 25				;keycode-->char code
	ld (hl), a				;store it to string
	inc hl					;increment storage string pointer
	call _vputmap				;display the letter
	jp keyloop				;get next letter or number
key_lowletter:
	pop af					;we PUSHED, we have to POP
	add a, 31				;keycode-->char code
	ld (hl), a				;store it to string
	inc hl					;next string spot
	call _vputmap				;display
	jp keyloop				;next
key_done:
	ld a, 0
	ld (hl), a				;zero-terminate the string
	ret					;exit

string:
	.db 0,0,0,0				;string storage


.end
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