A86:4 Questions

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A86:4 Questions


4 (possibly stupid to the advanced programmers) questions:

1) what the heck is text_shadow?

2) for this question, i shall cut and paste some code from Sqrxz:
            XScr		   = $C0F9
            XBlock		   = $C0FC
            LevelSize	   = $C0FD
    what do these things do?  i know they're equates and all that, but are
they kinda like the equivalent of variables?  Are $C0FC and those things just
spaces in the RAM, or are they ROM calls or what?

3) again taken as an example from Sqrxz: res appTextSave,(iy+appflags)
      what does this do?  i know it resets the bit in whatever appTextSave is,
but what are appTextSave and iy+appflags?

4) finally, i have built this program just to try to figure out if I knew how
to use sprites and the PutSprite routine......obviously not because either I'm
not getting a key correctly, or I just have a simple mistake with my program
that one of you ASM wizards could show me.


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

.org _asm_exec_ram

MainLoop45: 
 call _clrLCD
 call BUSY_OFF
 ld ix,NewSprite
 ld hl,$fc00
 ld bc,$4028
 call PutSprite
ASK_FOR_KEY: 
 call _getky
 cp K_LEFT
 jp z,LEFT
 cp K_RIGHT
 jp z,RIGHT
 cp K_SECOND
 jp z,SECOND
 cp K_EXIT
 jp z,EXIT
 jp ASK_FOR_KEY
LEFT:
 ld a,16
 cp b
 jr z,ASK_FOR_KEY
 dec b
 ld ix,NewSprite
 call PutSprite
 jr ASK_FOR_KEY
RIGHT:
 ld a,112
 cp b
 jr z,ASK_FOR_KEY
 inc b
 ld ix,NewSprite
 call PutSprite
 jr ASK_FOR_KEY
SECOND:  
 inc c
 inc c
 inc c
 ld b,35
Loop:
 push bc            ;push counter
 inc c
 ld ix,NewSprite2
 call PutSprite
 ld a,8
 cp c
 jp z,ASK_FOR_KEY
 pop bc              ;get back counter
 djnz Loop
EXIT:
 ret

 
;Input: b,c = x,y; ix = 8x8 sprite location 
;Output: sprite drawn; ix points to byte after sprite; bc unchanged 

PutSprite: 
 push bc                  ;save bc so that this routine can boast preserving
it 
 ld h,63                   ;CLEM's Findpixel 
 ld a,c                   ;           | 
;it goes through this whold PutSprite routine.  don't worry, i have all of it.
i just ended
;it here to take up less space.

NewSprite:
	.db %00000000
	.db %00000000
	.db %00000000
	.db %00000000
	.db %00011000
	.db %00111100
	.db %01111110
	.db %11111111


NewSprite2:
	.db %00000000
	.db %00000000
	.db %00000000
	.db %00000000
	.db %00011000
	.db %00011000
	.db %00011000
	.db %00011000

.end



well, i hope someone out there can find something wrong with my code.  I would
recommend running it in an emulator, as it will probably crash your calc.