> ld hl,DATA_AREA > ld (hl),0 > ld de,DATA_AREA+1 > ld bc,4095 > ldir
Nice. Looks much smaller and neater than mine. :) Thanks for the tip! Tony > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of ag0ny > Sent: Friday 19 October 2001 6:42pm > To: [EMAIL PROTECTED] > Subject: Re: Z80 loops > > > Hi, > > What about this? > > ld hl,DATA_AREA > ld (hl),0 > ld de,DATA_AREA+1 > ld bc,4095 > ldir > > Regards, > > > Tony Bedford wrote: > > > > Hi, > > > > I have a loop that needs to clear a 4096 byte area. > > I would like it to be as fast as possible, but this is > > not critical. > > > > Here's what I came up with: > > > > ; need to clear data area > > ; data area is 4096 bytes > > ; 4096 = (255*16)+16 > > > > ld hl,DATA_AREA > > ld c,16 > > > > @@start_loop1: > > > > ld b,255 > > @@clear_byte: > > ld (hl),0 > > inc hl > > djnz @@clear_byte > > > > dec c > > jp nz,@@start_loop1 > > > > ld b,16 > > @@start_loop2: > > ld (hl),0 > > inc hl > > djnz @@start_loop2 > > > > It appears to work OK, but surely there must be a > > simpler way or a faster way? > > > > Any suggestions? Does anyone know of any good docs on Z80 code > > optimisation? > > > > Thanks, > > Tony > > -- > > For info, see http://www.stack.nl/~wynke/MSX/listinfo.html > > -- > [EMAIL PROTECTED] - http://www.aamsx.org > -- > For info, see http://www.stack.nl/~wynke/MSX/listinfo.html > -- For info, see http://www.stack.nl/~wynke/MSX/listinfo.html
