On Sat, Oct 15, 2016 at 6:56 PM, Gerrit Heitsch <email@example.com> wrote: > On 10/14/2016 07:16 PM, Francesco Messineo wrote: >> >> yes, it was 8521 then. I'm sure at one point there was the 85xx >> version of the 6526. > > > Not 'there was', all 6526 after the end of '86 are internally 8521. They > just labeled them 6526 again, probably to avoid confusion. You can check > that by software, a timer IRQ behaves slightly different. Also, a good hint > is the '206A' and '216A' after the datecode. The '2' indicates HMOS-II > process. NMOS would have a '1' there. good to know, I've never looked deep enough on these chip processes, date codes and so on. > >> Even with TTL-compatible logic, they could invent any consistent >> numbering, like XXYY257 >> instead of 7708 and XXYY258 instead of 7709... >> For example, their 74LS245 equivalent was following that golden rule, >> so at one point they decided to "go insane" on numbering. > > > No really 'go insane', more along the lines of just counting up. The leading > '7' means HMOS-I, the next '7' means 'support logic' and then just start > from 00. 7700 was the 82S100-clone. as I said, at one point, they were making the 65245 (I have a few inside the VIC-20CR) and that is a replacement for the 74LS245. I'm not sure what process they used on these. Why not keeping the good practice and make a 77S100 for example? 77257 7706 and 77258 (just a few examples) would have been good too :) I'm sure most of us have to keep a list of equivalents to avoid putting the wrong replacement (I do need it). Frank Message was sent through the cbm-hackers mailing listReceived on 2016-10-15 18:00:21
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