23 Jan
2008
23 Jan
'08
10:22 a.m.
From: dkelvey at hotmail.com
Oops!! I blew it. I forgot an 'add hl,hl' !!!!!!$$$####
Here is the change using the sign bit instead. Still saves time and cycles
by not needing the DJNZ. One less cycle per loop. The and at the end
balances the ld B#7 but the ld a, #1 is one more byte. Still the jp
is faster than the jr for the 7 loops. Still 19 bytes!
div10:
ld a,#1
ld de,#-640d
divloop:
add hl,de
jr c,div1
sbc hl,de
div1:
rl a
add hl,hl
jp p,div1
add hl,hl
and #7F
ret
Dwight
Hi
It is getting bad, I'm dreaming solutions now.
Here is one that uses the minimum bytes but is slightly
slower because of the jr instead of the jp for the loop:
div10:
ld a,#2
ld de,#-1280d
divloop:
add hl,hl
add hl,de
jr c,div1
sbc hl,de
div1:
rl a
jr c,div1
add hl,hl
ret
This is 16 bytes. One could still reduce the loop clocks by
9 cycles at the cost of one more byte. This could be done
by replacing the jr c,div1 with a jp c,div1. ;)
Dwight
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