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Re: How do I make boot floopy? IMSAI + Northstar + CP/M?

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  • joshbensadon
    ... So is mine, they are very good capacitors. I brought them up slowly then did a ripple test on them. Power supply = 8.2V while drawing 5Amps with 620mV
    Message 1 of 19 , Mar 27, 2013
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      --- In midatlanticretro@yahoogroups.com, Systems Glitch <systems.glitch@...> wrote:
      >My IMSAI is running on the capacitors that came with it, as is the Cromemco Z-2D and CompuPro 8/16. That doesn't mean yours are guaranteed good, of course. Do bring it up on a variac to help in the reforming process if you want to try and keep the old caps.
      >
      > Thanks,
      > Jonathan


      So is mine, they are very good capacitors. I brought them up slowly then did a ripple test on them.
      Power supply = 8.2V while drawing 5Amps with 620mV ripple.

      Looked good enough for me. Last I checked, the drop out voltage of those 5V regulators was 7V.

      :)J
    • Systems Glitch
      ... Yup, that s sufficient! They ll regulate down to 7V; in fact, that s what I run my DC bench supply at when I use it with a small S-100 backplane. The 78/79
      Message 2 of 19 , Mar 27, 2013
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        > Looked good enough for me. Last I checked, the drop out voltage of those 5V regulators was 7V.

        Yup, that's sufficient! They'll regulate down to 7V; in fact, that's what I run my DC bench supply at when I use it with a small S-100 backplane. The 78/79 series regulators have pretty good ripple rejection if you provide adequate bypass around them.

        Thanks,
        Jonathan
      • s100doctor
        ... http://www.classiccmp.org/dunfield/img/index.htm I dont have time tonight to check Dunfield s disk images, to see if he has single-density N* disk images.
        Message 3 of 19 , Apr 1, 2013
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          > telmnstr@... wrote:
          > > I just looked. MDC-A4 is the floppy controller.
          >
          > Ah well... I owe Jonathan a beer. As he pointed out, this
          > is not good news. The CP/M stuff on Dave Dunfield's site
          > is double density. You should probably follow his lead
          > from here on out. I've never played with the one single
          > density N* controller I have and I've never played with N*
          > DOS.

          >
          > Bill S.
          >
          http://www.classiccmp.org/dunfield/img/index.htm

          I dont' have time tonight to check Dunfield's disk images, to see if he has single-density N* disk images. Check for yourself, later. But his Northstar NST serial transfer tools may be of some use to you. Since Dave's disk imaging can't make hard-sectored diskettes, he uses the native system to create or read the disk image and transfers it by serial cable to the MS-DOS system where the image files are created/read.

          People re-invent this technology over and over again; Dave's had a set of these transfer tools for various systems, for some time.

          herb
          retrotechnology.com
        • Systems Glitch
          ... Yes, he does...no CP/M but plenty of North Star DOS and related applications/usergroup disks. ... It definitely works with single-density disks, that s how
          Message 4 of 19 , Apr 2, 2013
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            > I dont' have time tonight to check Dunfield's disk images, to see if he has single-density N* disk images.

            Yes, he does...no CP/M but plenty of North Star DOS and related applications/usergroup disks.

            > But his Northstar NST serial transfer tools may be of some use to you.

            It definitely works with single-density disks, that's how I made mine. I don't recall right off whether I had to do anything special for single-density.

            > People re-invent this technology over and over again; Dave's had a set of these transfer tools for various systems, for some time.

            Sticking with a known-good imaging system and image format also helps to grow the available software for the community.

            Thanks,
            Jonathan
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