On 12/09/2011 03:18 AM, Segher Boessenkool wrote: >>>> If I remember correctly, I sent the chip to be read. It was from my >>>> oldest C64, serial number 32xxx, with ceramic DRAM chips (350ns IIRC) >>>> and 6569R1 and so on. >>> >>> An antique! >> >> Not only that, but the 6569R1 can be detected by software, at least >> this program can do it: >> >> http://noname.c64.org/csdb/release/?id=89406&show=summary >> >> With a 6569R3 or newer, it will just show '6569', but is somehow able >> to detect the R1 and list it. It is also quite good at detecting the >> rest of the hardware. With some I have no idea how it does it though. > > Excellent fun! It sees if the light pen interrupt can be triggered > between raster lines x'136 and 2; if so, it's a 6569R1, if not, not. Did they change the video timing or just the legal lines an LP IRQ can be triggered? On my 1084 monitor, the welcome screen looks OK no matter what VIC I use. > The discrete vs. CMOS core logic thing seems to check whether flipping > the VIC address space (VA15,VA14) glitches (doesn't on the CMOS). In what way does the old PLA design cause a glitch? > 6526 vs. 8521 CIA checks exactly how long it takes a timer to trigger > (8521 is a clock cycle earlier it seems). Hm? From what I read everywhere, the HMOS-CIA (8521 or 6526 after week 4x in 1986) takes an extra cycle with the timer IRQ compared to the NMOS 6526. >> Demos written for the 6569R3 or higher look quite odd on the R1. > > Because of the luminance palette difference, I take it? Or is there > some more awesome difference :-) When testing a C64, I use the type check program mentioned above plus a RAM test and the 'Edge of Disgrace' demo. The latter has a few 'plasma' effects and on those you notice that they were written for a 9-luma VIC. On the 6569R1 they look less smooth. To bad no one has yet been able to find a software trick to distinguish between the 6510 and the 8500. :) Gerrit Message was sent through the cbm-hackers mailing listReceived on 2011-12-10 19:00:03
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