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Old 27th Oct 2021, 12:23 am   #232
SiriusHardware
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Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,484
Default Re: Commodore PET 2001 voltage regulators

On more careful inspection I notice that my All07A Eprom programmer has a fixed algorithm for TMS2732 which applies 25V VPP but also 6V VCC during programming. The Hitachi datasheets don't make any suggestion of doing this on their chips, or not that I have found so far, so it might be unsafe to try to directly program the HN462532s as though they are TMS2532s.

If I look up how the programmer programs more conventional 2732s it uses +25V VPP but only 5V VCC, so it might be safer to make an adaptor to twist the TMS2532 / HN462532 pinout into the footprint of a 2732 and select 2732 (generic) in the programmer's menu to make sure it only uses the basic 50mS programming pulse, and not some manufacturer specific fast algorithm.

I'll probably try it both ways - the second way, if that works, would be more widely useful for the rest of you who probably can program 2732 / 2732A but not 2532 / 2532A due to its less common pinout.

I hear a lot of noise about the limitations of those popular TL886 programmers, mostly that they can't generate enough output voltage to properly support 25V VPP devices like the 2716, 2732, although they may be able to program the '...A' versions which are usually 21V.
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