Hello, * On Fri, Sep 25, 2009 at 07:49:22PM +0200 Thomas Giesel wrote: > > yes, old kernals fill the colorram with the value taken from $d021, > > new kernals fill it with the value from $0286. > > > > There's even more, see > http://zimmers.net/anonftp/pub/cbm/firmware/computers/c64/revisions.txt > > "$E57C-$E599: (compute screen address)" looks suspicious. Yesterday I > found out that putchar overwrites I/O memory beyond the color RAM. > Possibly it's used out of screen bounds accidently, I'm still searching > for the issue. And this wouldn't explain why it doesn't work with 02. That correction fixes the problem with the -02 KERNAL where the C64 executes LOAD + RUN after you entered 80 characters into the last row, then press BACKSPACE. As said, LOAD and RUN is executed, and you cannot enter any keys anymore. Even RUN/STOP + restore does not work. That's because the COLOR RAM pointer points into the $DC00 area in this special case. From my (still incomplete) analysis, I think this fix is only needed if you output the backspace. Feel free to proove me wrong. ;) Regarding the color ram initialisation: The -01 KERNAL used hard-coded white ($01), the -02 KERNAL used the background color (according to some web pages, because early VIC-II had a problem with flickering, which was circumvented with this change), and the -03 KERNAL used the foreground color. IMHO, it is not a bug of the -02 KERNAL, but YMMV. Regards, Spiro. -- Spiro R. Trikaliotis http://opencbm.sf.net/ http://www.trikaliotis.net/ http://www.viceteam.org/ ---------------------------------------------------------------------- To unsubscribe from the list send mail to majordomo@musoftware.de with the string "unsubscribe cc65" in the body(!) of the mail.Received on Sat, 26 Sep 2009 10:33:56 +0200
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