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Re: 82S141 PROMs

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  • Mike
    Mike, I ve encountered burned bi-polar PROMs sold as new only once, and the seller refunded my money, so it wasn t a big problem. arcadechips.com has
    Message 1 of 7 , Feb 14, 2012
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      Mike,

      I've encountered burned bi-polar PROMs sold as "new" only once, and the seller refunded my money, so it wasn't a big problem.

      arcadechips.com has excellent prices for proms, including a good selection of bi-polar varieties.

      Regards,
      Mike Willegal

      --- In midatlanticretro@yahoogroups.com, Mike Loewen <mloewen@...> wrote:
      >
      > On Fri, 27 Jan 2012, Mike Loewen wrote:
      >
      > > I'm looking for a source for at least six Signetics 82S141 Bi-polar
      > > PROMs for my HP project. Common substitutes are National 74S474, MMI
      > > 6341-1, TI 28S46, Harris 7641-5, AMD 27S31. Best price I've found so far
      > > is $12 a piece at hobbyroms.com. I was faked out by a false lead at
      > > electronicplus.com - they don't have any left.
      > >
      > > Any ideas on sources? My Data I/O 29B should be able to handle them.
      >
      > I received six National 74S474 PROMs from Unicorn Electronics, and
      > discovered that three of them were not blank (on my Data I/O 29B). Is
      > this a common occurrence for old stock?
      >
      >
      > Mike Loewen mloewen@...
      > Old Technology http://sturgeon.css.psu.edu/~mloewen/Oldtech/
      >
    • dfnr2
      Hi Mike, I think it is common. I think a lot of these parts were ordered pre-programmed at the factory, so a lot of New old-stock parts may actually be
      Message 2 of 7 , Feb 14, 2012
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        Hi Mike,

        I think it is common. I think a lot of these parts were ordered pre-programmed at the factory, so a lot of "New" old-stock parts may actually be programmed, and it would be difficult for a distributor to tell without actually testing.

        For what it's worth, I hadn't heard of Unicorn at that time, and by now, I have bought a number of parts from them, and have found their service and their parts to be excellent. I would definitely call them if your part it pre-programmed.

        A while back, I repaired an Asteroids Deluxe board, and I bought several 74S287 and 82S129 proms from one mail order company and Fry's, and found them all to be pre-programmed. At first I thought I was doing something wrong. Here's the thread:

        http://groups.google.com/group/rec.games.video.arcade.collecting/browse_thread/thread/f9b9c721a8130baa/8281bfdf48f56808?q=#8281bfdf48f56808

        I finally got a couple of blank PROMS from a vintage arcade parts seller online.

        BTW, here's my repair log for that board:

        http://groups.google.com/group/rec.games.video.arcade.collecting/browse_thread/thread/9e7c79a72ed8a8af/673211fb622143f1


        Dave
      • Mike Loewen
        ... Thanks, Mike, I found arcadechips.com last night and he supposedly has them in stock. I left a message, asking about them, as well as one for Unicorn.
        Message 3 of 7 , Feb 14, 2012
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          On Tue, 14 Feb 2012, Mike wrote:

          > I've encountered burned bi-polar PROMs sold as "new" only once, and the seller refunded my money, so it wasn't a big problem.
          >
          > arcadechips.com has excellent prices for proms, including a good selection of bi-polar varieties.
          >
          > Regards,
          > Mike Willegal

          Thanks, Mike, I found arcadechips.com last night and he supposedly has
          them in stock. I left a message, asking about them, as well as one for
          Unicorn.


          Mike Loewen mloewen@...
          Old Technology http://sturgeon.css.psu.edu/~mloewen/Oldtech/
        • Mike Loewen
          Just to be on the safe side, I ran through the complete voltage and performance checks for the Data I/O 29B and UniPak2B. All voltages and waveforms were well
          Message 4 of 7 , Feb 16, 2012
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            Just to be on the safe side, I ran through the complete voltage and
            performance checks for the Data I/O 29B and UniPak2B. All voltages and
            waveforms were well within spec. I felt like a lab weenie, again. :-)


            Mike Loewen mloewen@...
            Old Technology http://sturgeon.css.psu.edu/~mloewen/Oldtech/
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