Graphic glitch in tape loading screen

Michael Plate · Post by **Michael Plate** » Sun Oct 15, 2006 2:06 pm

I noticed a graphic glitch in a loading screen when loading the TAP image with CCS64 v3.1 but I cannot see this glitch when loading it with WinVICE v1.20.

Here's the CCS64 screenshot (take a look at the last letter of the word 'LIMITED'):

Here's how it looks with WinVICE:

The tape can be fetched here!

emulator · Post by **emulator** » Fri Jul 13, 2007 1:38 am

The bug is still there in the v3.3.

Post by **Stuart Toomer** » Mon Jul 16, 2007 9:00 pm

I have passed this on to Hakan for investigation/fixing.

Post by **Stuart Toomer** » Fri Jul 20, 2007 5:38 pm

I am informed that this is fixed if you change the Memory Reset Pattern setting, so the game must be relying upon some particular hardware configuration of memory data.

emulator · Post by **emulator** » Tue Jul 24, 2007 5:28 pm

Stuart Toomer wrote:I am informed that this is fixed if you change the Memory Reset Pattern setting, so the game must be relying upon some particular hardware configuration of memory data.

Could it be it relies on the REAL C64 memory pattern? For some odd reason, what is called a "normal" memory pattern in CCS64 is actually INVERSED to that of the real thing. So there is a 00 instead of FF, and conversely, FF instead of 00. I fail to see any sense in it. What is worse, there's no way to choose a truly normal pattern.

Post by **Stuart Toomer** » Sat Jul 28, 2007 3:57 pm

emulator wrote:
Stuart Toomer wrote:I am informed that this is fixed if you change the Memory Reset Pattern setting, so the game must be relying upon some particular hardware configuration of memory data.

Could it be it relies on the REAL C64 memory pattern? For some odd reason, what is called a "normal" memory pattern in CCS64 is actually INVERSED to that of the real thing. So there is a 00 instead of FF, and conversely, FF instead of 00. I fail to see any sense in it. What is worse, there's no way to choose a truly normal pattern.

Different revisions of the C64 hardware had different patterns of 'initialised' memory data, which is why that option exists in CCS64. I guess it was just due to the cheapness of the hardware when the different C64 revisions were manufactured. Some games rely upon certain patterns of 'initialised' memory data.

zaphod · Post by **zaphod** » Sun Nov 04, 2007 4:21 am

Actually, the c64 performs NO initialization of RAM whatsoever! At least mine. if you flick the power off and back on,it will usually be similar to what it had before but not identical.

The c64 does not clear memory on reset or on poweron, except for the start of basic and the needed vectors to boot to basic.