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Re: [midatlanticretro] Re: RCA COSMAC Microkit

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  • B. Degnan
    Yes, I was the one who brought up the COSMAC Microkit in 2009 when I discovered that they existed from a magazine article (on my site). Joyce appears to have
    Message 1 of 13 , Apr 5, 2013
      Yes, I was the one who brought up the COSMAC Microkit in 2009 when I
      discovered that they existed from a magazine article (on my site). Joyce
      appears to have misunderstood me at the time in that I did not actually
      have a Microkit, I was only asking her if *she* had one...but perhaps she
      can read the future.

      I plan to sell my Steinberger Bass (anyone interested?) to pay for the
      computer, because I could not justify the expense otherwise. I figured
      this is a once in a lifetime thing and I am in the "go for it!" camp when
      it comes to things like that. And I never play that bass anyway. :-)

      Bill



      -------- Original Message --------
      > From: "Bill Dromgoole" <drummy@...>
      > Sent: Friday, April 05, 2013 9:31 PM
      > To: midatlanticretro@yahoogroups.com
      > Subject: Re: [midatlanticretro] Re: RCA COSMAC Microkit
      >
      > Bill, do you remember talking about the MicroKit 1 in 2009?
      > Look at message #14763 when you corresponded with Joyce Wiesbecker about
      it on
      > this forum.
      > I think your subconscious mind kicked in and made you buy this.
      >
      > Begin Quote
      > " You're right about the Microkit 1. It was RCA's hardware development
      kit
      > targeted at design engineers looking to embed a microprocessor into their

      > equipment. I never even saw one of them, only read the product brochure,

      > because - Man!!! - that thing cost thousands of dollars, and RCA made its

      > employees buy those kits at full price! That was an RCA Somerville
      project, so
      > my father had no input. My father was building the prototypes (in our
      basement)
      > for all the other computers I mentioned, and his group at the Sarnoff
      Labs was
      > developing those models, so he got to bring home one of each of the final

      > production models. (Yes, every aspect of the 1802 - microprocessor,
      computers,
      > videogame, and kits - was a skunkworks project.)
      >
      > You really have a collectible in that Microkit 1, Bill. It was the
      > predecessor to the VIP. Dad pitched the VIP as a cheaper, more accessible
      (and
      > therefore better selling tool to OEMs) than the Microkit 1. But it was
      also the
      > only way he could get RCA to offer a hobbyist computer since management
      was dead
      > set against the idea :). Between the limited production run, the high
      cost, and
      > the fact that most of them were the property of the employer, not the
      engineer,
      > your Microkit 1 is probably one of the rarest production model computers
      still
      > around. (Even I had forgotten it existed until you mentioned it!)
      > Congratulations on your rare treasure!
      >
      > Joyce"
      > End Quote.
      >
      > Bill Drom
      >
      ----------------------------------------------------------------------------
      -------------------------------
      > ----- Original Message -----
      > From: "B. Degnan" <billdeg@...>
      > To: <midatlanticretro@yahoogroups.com>
      > Sent: Friday, April 05, 2013 3:04 PM
      > Subject: re: [midatlanticretro] Re: RCA COSMAC Microkit
      >
      >
      > > Mike,
      > >
      > >>
      > >> That is really cool. Are you going to try to get it going? Do you
      have
      > > any software?
      > >>
      > >
      > > Just got it, I have not even tested the power yet. .. I have this
      Scelbi
      > > kit to get started first!
      > >
      > >> The group of us folks working on SCELBI's are very lucky in that
      SCELBI
      > > consulting published most of their software in book form. SCELBAL
      BASIC
      > > has been digitized a few years back, and I'm working on digitizing and
      > > running some of their other published programs on reproduction
      hardware.
      > > It's been a real trip. We think that some of this stuff hasn't been
      run on
      > > physical hardware (or otherwise) in 25 or more years.
      > >>
      > >
      > > Basically I picked this COSMAC up because it was now or never. What to
      do
      > > and when to do it to be determined. I will be bringing both the Scelbi
      and
      > > the COSMAC to the MARCH open house most likely.
      > >
      > > Bill
      > >
      > >
      > >
      >
      >
      >
      > ------------------------------------
      >
      > Yahoo! Groups Links
      >
      >
      >
    • B. Degnan
      ... the ROM as inverted so you didn t have to put another buffer chip on the bus. If you re trying to disassemble it, just run it through a program to flip
      Message 2 of 13 , Apr 18, 2013
        >
        > In this case, if you had an inverted bus, it would make sense to store
        the ROM as inverted so you didn't have to put another buffer chip on the
        bus. If you're trying to disassemble it, just run it through a program to
        flip the bits.
        >
        >
        -Thanks Dave-
      • joshbensadon
        ... I don t think Bill has determined that the bus is inverted. I observed the dump that Bill posted didn t make sense as 1802 machine code until I guessed
        Message 3 of 13 , Apr 18, 2013
          --- In midatlanticretro@yahoogroups.com, "B. Degnan" <billdeg@...> wrote:
          >
          >
          > >
          > > In this case, if you had an inverted bus, it would make sense to store
          > the ROM as inverted so you didn't have to put another buffer chip on the
          > bus. If you're trying to disassemble it, just run it through a program to
          > flip the bits.
          > >
          > >
          > -Thanks Dave-


          I don't think Bill has determined that the bus is inverted.

          I observed the dump that Bill posted didn't make sense as 1802 machine code until I guessed that the bits might be inverted.

          I am only guessing that the bus is inverted and wish to advise Bill to look out for that.

          I could be totally out to lunch, since it is an 1801 chip set.

          :)J
        • B Degnan
          When I get back from a brief vacation I will look up the commands from their HEX values, and/or convert to an Intel record that would be easier to assemble. I
          Message 4 of 13 , Apr 19, 2013
            When I get back from a brief vacation I will look up the commands from their
            HEX values, and/or convert to an Intel record that would be easier to
            assemble. I believe I have the instruction set in my
            vintagecomputer.net/RCA/COSMAC directory, or elsewhere. If assembly is
            possible. No way to know about whether inversion is necessary yet.



            -----Original Message-----
            From: midatlanticretro@yahoogroups.com
            [mailto:midatlanticretro@yahoogroups.com] On Behalf Of joshbensadon
            Sent: Thursday, April 18, 2013 1:39 PM
            To: midatlanticretro@yahoogroups.com
            Subject: [midatlanticretro] Re: RCA COSMAC Microkit

            --- In midatlanticretro@yahoogroups.com, "B. Degnan" <billdeg@...> wrote:
            >
            >
            > >
            > > In this case, if you had an inverted bus, it would make sense to
            > > store
            > the ROM as inverted so you didn't have to put another buffer chip on
            > the bus. If you're trying to disassemble it, just run it through a
            > program to flip the bits.
            > >
            > >
            > -Thanks Dave-


            I don't think Bill has determined that the bus is inverted.

            I observed the dump that Bill posted didn't make sense as 1802 machine code
            until I guessed that the bits might be inverted.

            I am only guessing that the bus is inverted and wish to advise Bill to look
            out for that.

            I could be totally out to lunch, since it is an 1801 chip set.

            :)J




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