Loading ...
Sorry, an error occurred while loading the content.

33884Re: [midatlanticretro] Intertec Superbrain

Expand Messages
  • joshbensadon
    Jan 2, 2014
    • 0 Attachment
      ---In midatlanticretro@yahoogroups.com, <pet4032@...> wrote:

      >Is this the same Superbrain that you couldn't find a good EPROM to dump?  Where did you finally find one?
      >Cheers,
      >Bryan

      Happy New Year Bryan,

      Yes, the same one.  Well, it turned out in the end my eprom was not bad / blank at all.  Dave Dunfield solved a 27 year old (forgotten) mystery for me.  As it turns out, not all 2716's are interchangeable.  The TMS2716's from Texas Instruments and Motorola require 3 voltage rails, while the later 2716's from Intel and a dozen other makers only required a single 5V.  I remember using these single 5V Eproms 27 years ago and was baffled that they only used 5V when I had a data sheet at home for the TMS2716.  Information back then wasn't easily found like it is today, so I forgot about it.  My regular eprom programmer requires an adapter for the TMS2716, which I didn't notice.  My first step in trouble shooting is to do a dump of the eprom, for good measure.  Which is why I never continued the job.  Turned out that the Z80 CPU was bad... that's my 3rd bad CPU chip for 2014.  Which is funny, because I haven't seen many CPU chips go bad.

      Anyway, lesson learned.  TMS2716 <> xx2716

      Cheers,
      Josh

    • Show all 9 messages in this topic