A82: Find_Pixel once more...


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A82: Find_Pixel once more...




Hey Guys-
  Ok, even though I sent an email before about Find_Pixel, I got Adamman's
routine.. but I didn't mess w/it... Thus, I have 2 questions:

1. Does your routine [Adamman, or anyone please answer :] use the original
input as Find_Pixel.. i wanted a simple routine EXACTLY the same
input/output as the ROM_CALL...

2. I looked through my archive, and found this "Mardellian" routine [Jimmy
Mardell] from his port of Solytare to the 86... sure, its longer than
Eble-Yopp, but how could I convert this to the 82/3, and does it really have
the same input/output as the ROM_CALL?

Here it is ...

;Find_Pixel Routine
;By Jimmy Mardell
;Used in Solytare 86 Port
FIND_PIXEL:
 push bc
 push de
 ld hl,ExpTable
 ld d,0
 ld a,b
 and $07
 ld e,a
 add hl,de
 ld e,(hl)
 ld h,d
 srl b
 srl b
 srl b
 ld a,c
 add a,a
 add a,a
 ld l,a
 add hl,hl
 add hl,hl
 ld a,e
 ld e,b
 add hl,de
 pop de
 pop bc
 ret
ExpTable:
 .db $80,$40,$20,$10,$08,$04,$02,$01


What does ExpTable do, I don't get that either!
And is srl = x2?  and does and -7 kinda mask a bit or something????
Any help would be appreciated.  Thanks in advance,
                                                                            
    -Ahmed

P.S - Sam, what's the status on ZTetris... [esp. the Crash bug that splits
the screen...]