Is anyone testing the differences between the CIAs 6526 (orA)(C64) and 8521 (C128 and some C64c's) or 8520 Amiga 500/1000/2000/3000 -- that address, $DExx, is in the CIA. What about differences between 8501(7501) and 8502 and 8500? > >---------- Forwarded message ---------- >Date: Sun, 30 Jul 2000 11:43:01 +0200 >From: Nicolas Welte <welte@chemie.uni-konstanz.de> >Reply-To: cbm-hackers@dot.tcm.hut.fi >To: cbm-hackers@dot.tcm.hut.fi >Subject: Re: 6510 and 8500 differences > >Richard Atkinson wrote: >> I'm going to leave the C64C and C128D on all night. Depending on how low >> the 8500 result is tomorrow, it may be possible to arbitrarily set a >> 'reasonable' cut-off point between 6510 and 8500, but it would only be >> accurate after the machines have been on for some time and there would be >> the possibility of erroneously detecting C64s as C64Cs for recently turned >> on machines. > >Thanks for all the measurements, Richard! I'm also quite amazed that we >have a temperature sensor in our CPUs, this is something that just >became popular with the Pentium III and it's integrated temperature >diode. We had it for 18 years! (But didn't know about it) > >A bit more accurate measurements (cycle exact with the CIA timers, >connected to a 32bit timer) would be nice, but if there already is an >overlap between 8500 and 6510 values it doesn't really make sense. I did >some measurements of that kind already on the two SID types, but soon I >found one 8580 that wasn't much different from most of the 6581, so I >kind of stopped looking at more machines. I might have another go and >study the temperature dependenance, if it also affects the SID effect. >But then I would also include CPU measurements so I could get both >values at once. > >Are there any more registers with unconnected bits that could be looked >at in a similar manner? I don't know of any such bits in the CIAs or in >the VIC-II. > >> How well defined is the $DExx functionality difference between C64s and >> C64Cs? I feel sure we're on the right track, but will have to put in some >> considerable refinements to the process to achieve a high level of >> accuracy from the moment a machine is powered up. > >In any case a machine type detection program must examine this >functionality, but I already said that a few (probably slightly damaged) >"C64Cs" fail this test. It also isn't a 100% sign for a 8500. > >Nicolas > > >- >This message was sent through the cbm-hackers mailing list. >To unsubscribe: echo unsubscribe | mail cbm-hackers-request@dot.tcm.hut.fi. -- --------------------------------------------------------------- |Raymond C. Bryan 651-642-9890 vox | The battle is sometimes | |Raymond Computer 651-642-9891 fax | to the small for | |795 Raymond Ave -email: raycomp | the bigger they are | |St Paul MN 55114 @visi.com | the harder they fall. | |USA Amiga - Commodore | -- James Thurber -- | --------------------------------------------------------------- - This message was sent through the cbm-hackers mailing list. To unsubscribe: echo unsubscribe | mail cbm-hackers-request@dot.tcm.hut.fi.
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