On 08/24/2011 08:23 PM, Marko MÃ¤kelÃ¤ wrote: > On Wed, Aug 24, 2011 at 07:05:36PM +0200, Gerrit Heitsch wrote: >>> The end of the story was that I went to a CES show and woman pulled >>> me into her booth to show me the educational software she had written >>> for the C64. I remember her display had nasty lines in it, she didnâ€™t >>> yet have access to the R7 chips. >> >> The 6567 before R7 were that bad? Since I live in PAL land I have >> never seen them and the 6569R3 and later always produced a very good >> picture if the Monitor was hooked up by Chroma/Luma. > > I live in PAL land too, but I traded a few 6567 chips for 6569. As far > as I remember, the 6567R8 is comparable to the 6569R3. I got one or two > of them. The oldest NTSC chip that I encountered was a 6567R56A, which > is about the same picture quality as the 6569R1 (both in ceramic case). One thing I noticed about the 6569R3 and R5 (the latter in plastic) is that they run very hot (I almost burned my finger on an R5 that didn't have a heatsink) but that doesn't seem to cause any problems while you always hear with the 8501 and TED that they overheat and fail quickly. More and more I think that the 8501 and TED fail not due to overheating but them being MOS earliest attempts at HMOS-II and the process not being stable yet. The later 8xxx MOS chips don't seem to have that problem. If that's the case, using a heatsink on a 8501 or TED will only delay the premature failure (compared to other chips) but not stop it. Oh... and I found out what happens if you have a 6569R3 where the +12V supply is only +8V (due to a dead capacitor), system still runs but you only get color while the chip is cold, once it heats up the picture becomes black and white. Gerrit Message was sent through the cbm-hackers mailing listReceived on 2011-08-24 19:00:23
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