Good question! I consulted charts from both the Leventhal book and the C-64 PRG and both state clearly that CLC and SED are 2-cycle commands. I don't quite know why either. They are both done internally in the 6502 and neither needs to fetch or strore anything to the system buss! You'd think that a 1-bit adjustment of an internal register would be a 1-cycle instruction! Either way you look at it, the decimal mode technique of converting a binary nybble to an ASCII encoded hex digit is a unique approach! I've never seen that algorithm in any book or program before. Perhaps because the compare-branch algorithm uses fewer cycles ;-) --- Ruud Baltissen <Ruud.Baltissen@abp.nl> wrote: > > Have I miscounted my cycles? Is there ANY > circumstance > > under which the first routine is 'quicker' than > the > > second??? :-/ > > The only thing I can think of is that the author > made the same mistake as I > did: assuming that the above 1 byte commands only > take one cycle. Personal > remark: why do they need two??? > > Groetjes, Ruud > > http://Ruud.C64.org > > > > - > This message was sent through the cbm-hackers > mailing list. > To unsubscribe: echo unsubscribe | mail cbm-hackers-request@dot.tml.hut.fi. ===== Get a FREE 6Mb webmail box from go6502! - http://www.geocities.com/profdredd As low as 2.99% Intro APR from NextCard! - http://www.nextcard.com/index6.html?ref=aff0074521 PayPal is the FAST FREE and SECURE way to send money! - https://secure.paypal.x.com/refer/pal=profdredd%40yahoo.com __________________________________________________ Do You Yahoo!? Yahoo! Auctions - Buy the things you want at great prices. http://auctions.yahoo.com/ - This message was sent through the cbm-hackers mailing list. To unsubscribe: echo unsubscribe | mail cbm-hackers-request@dot.tml.hut.fi.
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