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82S141 PROMs

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  • Mike Loewen
    Hey, chip gurus: 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
    Message 1 of 7 , Jan 27, 2012
      Hey, chip gurus:

      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.


      Mike Loewen mloewen@...
      Old Technology http://sturgeon.css.psu.edu/~mloewen/Oldtech/
    • Mike Loewen
      ... 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
      Message 2 of 7 , Feb 13, 2012
        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/
      • Dave McGuire
        ... That s pretty rare; these guys usually know about OTP devices. Unicorn will probably swap them out. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
        Message 3 of 7 , Feb 13, 2012
          On 02/13/2012 10:54 PM, Mike Loewen wrote:
          > 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?

          That's pretty rare; these guys usually know about OTP devices.
          Unicorn will probably swap them out.

          -Dave

          --
          Dave McGuire, AK4HZ
          New Kensington, PA
        • 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 4 of 7 , Feb 14, 2012
            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 5 of 7 , Feb 14, 2012
              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 6 of 7 , Feb 14, 2012
                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 7 of 7 , Feb 16, 2012
                  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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