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88S4k ram chips TMS4060NL question

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  • tkaragiris
    Hi All, I spent a few hours on the weekend messing around with my Cromemco Bytesaver card. I managed to successfully write to many proms, I ve got two types
    Message 1 of 3 , Sep 2, 2012
      Hi All,

      I spent a few hours on the weekend messing around with my Cromemco
      Bytesaver card. I managed to successfully write to many proms, I've
      got two types of proms: Fairchild 2708's and Intel 2708's. I found that
      the Fairchild proms would write successfully using the default 30 second
      write time, which is the default for the Bytemover 3.1 program, but the
      Intels required a manual write time of around 3 minutes. But I managed
      to write to both successfully.

      On another note, I managed to use the Bytemover program as memory card
      tester. The Bytemover program copies a 1k chunk of memory from one
      location to another, so I figured that I could copy the 1k chunk
      beginning with the bytemover program to the first k and then use that
      instance to copy to the second k and so on. While the bytemover program
      only occupies a small portion of the 1k of memory, when you run it, it
      compares the copy of 1k memory to the source and lights up the INTE
      light if the copies are the same after it executes.

      Using this method I determined that one of my 88S4k ram cards has
      problems, as it failed to copy the 1 k chunks successfully beyond the
      second k of memory. On further testing of this card I obseverd that
      values I deposited in it's memory would change after a few seconds after
      sitting in that memory location. To cut the story short I determined
      that two of the ram chips on that board had cracked pins and once I
      removed those two chips I could then write values to the remaining chips
      and those values would remain stable in the memory, although they were
      missing two of the eight bits.

      The ram chips on the card are marked TMS4060NL, I managed to locate some
      on ebay with the same code in the first row of characters but the second
      row is different to the ones I have. Does this matter? Is the second
      row of characters just a serial number or something?

      See example here:

      http://www.ebay.com/itm/TEXAS-INSTRUMENTS-TMS4060NL-22-PIN-DIP-QTY-DISCO\
      UNT-NEW-PARTS-QUANTITY-1-/370591902244?pt=LH_DefaultDomain_0&hash=item56\
      48ffaa24

      The second row of characters begins with MBKS..., this is different to
      the chips in my 88S4K card.
    • Bob Grieb
      7923 is a date code.  Those chips were made in the 23rd week of 1979. Not sure about the MBKS, but I would guess that it s not important.    Bob
      Message 2 of 3 , Sep 2, 2012
        7923 is a date code.  Those chips were made in the 23rd week of 1979.

        Not sure about the MBKS, but I would guess that it's not important.

           Bob



        From: tkaragiris <tkaragiris@...>
        To: altaircomputerclub@yahoogroups.com
        Sent: Sunday, September 2, 2012 8:32 PM
        Subject: [Altair Computer Club] 88S4k ram chips TMS4060NL question

         
        Hi All,

        I spent a few hours on the weekend messing around with my Cromemco
        Bytesaver card. I managed to successfully write to many proms, I've
        got two types of proms: Fairchild 2708's and Intel 2708's. I found that
        the Fairchild proms would write successfully using the default 30 second
        write time, which is the default for the Bytemover 3.1 program, but the
        Intels required a manual write time of around 3 minutes. But I managed
        to write to both successfully.

        On another note, I managed to use the Bytemover program as memory card
        tester. The Bytemover program copies a 1k chunk of memory from one
        location to another, so I figured that I could copy the 1k chunk
        beginning with the bytemover program to the first k and then use that
        instance to copy to the second k and so on. While the bytemover program
        only occupies a small portion of the 1k of memory, when you run it, it
        compares the copy of 1k memory to the source and lights up the INTE
        light if the copies are the same after it executes.

        Using this method I determined that one of my 88S4k ram cards has
        problems, as it failed to copy the 1 k chunks successfully beyond the
        second k of memory. On further testing of this card I obseverd that
        values I deposited in it's memory would change after a few seconds after
        sitting in that memory location. To cut the story short I determined
        that two of the ram chips on that board had cracked pins and once I
        removed those two chips I could then write values to the remaining chips
        and those values would remain stable in the memory, although they were
        missing two of the eight bits.

        The ram chips on the card are marked TMS4060NL, I managed to locate some
        on ebay with the same code in the first row of characters but the second
        row is different to the ones I have. Does this matter? Is the second
        row of characters just a serial number or something?

        See example here:

        http://www.ebay.com/itm/TEXAS-INSTRUMENTS-TMS4060NL-22-PIN-DIP-QTY-DISCOUNT-NEW-PARTS-QUANTITY-1-/370591902244?pt=LH_DefaultDomain_0&hash=item5648ffaa24

        The second row of characters begins with MBKS..., this is different to
        the chips in my 88S4K card.



      • tkaragiris
        Bob, Thanks, that s probably why those chips look a bit different they would be a good three or four years newer than those on the card.
        Message 3 of 3 , Sep 2, 2012
          Bob,

          Thanks, that's probably why those chips look a bit different they would be a good three or four years newer than those on the card.



          --- In altaircomputerclub@yahoogroups.com, Bob Grieb <bobgrieb@...> wrote:
          >
          > 7923 is a date code.  Those chips were made in the 23rd week of 1979.
          >
          > Not sure about the MBKS, but I would guess that it's not important.
          >
          >    Bob
          >
          >
          >
          >
          > ________________________________
          > From: tkaragiris <tkaragiris@...>
          > To: altaircomputerclub@yahoogroups.com
          > Sent: Sunday, September 2, 2012 8:32 PM
          > Subject: [Altair Computer Club] 88S4k ram chips TMS4060NL question
          >
          >
          >  
          > Hi All,
          >
          > I spent a few hours on the weekend messing around with my Cromemco
          > Bytesaver card. I managed to successfully write to many proms, I've
          > got two types of proms: Fairchild 2708's and Intel 2708's. I found that
          > the Fairchild proms would write successfully using the default 30 second
          > write time, which is the default for the Bytemover 3.1 program, but the
          > Intels required a manual write time of around 3 minutes. But I managed
          > to write to both successfully.
          >
          > On another note, I managed to use the Bytemover program as memory card
          > tester. The Bytemover program copies a 1k chunk of memory from one
          > location to another, so I figured that I could copy the 1k chunk
          > beginning with the bytemover program to the first k and then use that
          > instance to copy to the second k and so on. While the bytemover program
          > only occupies a small portion of the 1k of memory, when you run it, it
          > compares the copy of 1k memory to the source and lights up the INTE
          > light if the copies are the same after it executes.
          >
          > Using this method I determined that one of my 88S4k ram cards has
          > problems, as it failed to copy the 1 k chunks successfully beyond the
          > second k of memory. On further testing of this card I obseverd that
          > values I deposited in it's memory would change after a few seconds after
          > sitting in that memory location. To cut the story short I determined
          > that two of the ram chips on that board had cracked pins and once I
          > removed those two chips I could then write values to the remaining chips
          > and those values would remain stable in the memory, although they were
          > missing two of the eight bits.
          >
          > The ram chips on the card are marked TMS4060NL, I managed to locate some
          > on ebay with the same code in the first row of characters but the second
          > row is different to the ones I have. Does this matter? Is the second
          > row of characters just a serial number or something?
          >
          > See example here:
          >
          > http://www.ebay.com/itm/TEXAS-INSTRUMENTS-TMS4060NL-22-PIN-DIP-QTY-DISCOUNT-NEW-PARTS-QUANTITY-1-/370591902244?pt=LH_DefaultDomain_0&hash=item5648ffaa24
          >
          > The second row of characters begins with MBKS..., this is different to
          > the chips in my 88S4K card.
          >
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