Loading ...
Sorry, an error occurred while loading the content.

24690Re: IMSAI front panel ECO question

Expand Messages
  • josh6502
    Mar 16, 2012
    • 0 Attachment
      An original IMSAI Manual! Nice! You definitely don't want to spill your coffee on that, in fact, you want to research ways to minimize yellowing of the paper, etc.

      I think I have already found your web site. I'm just still gearing up for this. The system I have included 2 floppy controllers and I'm a little confused why there was 2. Anyway, I'm having too much fun figuring this out without any hand holding, but it's good to know help is out there.

      So far, I've been able to key in a 16 byte program to save or load RAM through a serial port. I have a RAM mystery to unfold... you see there are two 16K cards installed, yet I can read/write 48K. I'm guessing either one of the cards (the one I don't have documentation on) might be a 32K OR the same ram is mapped twice. Tonight I'm writing a unique pattern to RAM and reading it back, futher, I'll cross check by looking up the data sheets on the RAM chips.

      Once this mystery is cleared up, it's time learn how to write to a Floppy and deciding which controller to use. I'll definitely read your site! Option 2 might be to load CP/M & the Format command directly to RAM and let it format the floppy disk.


      Cheers,
      Josh

      --- In midatlanticretro@yahoogroups.com, Richard Cini <rich.cini@...> wrote:
      >
      > Josh --
      >
      > Indeed you are right. It was all about sharingŠsharing
      > knowledgeŠexperienceŠetc. Sharing enabled the technology to disseminate
      > quickly and to grow into what it is today. That growth made the world
      > better, and that was a strong cultural belief of the people who were at the
      > forefront of this in the early 1970's. At some point, that altruistic
      > feeling went away and other feelings took over. {That's the limit of my
      > sociology knowledge :-))
      >
      > I have an original IMSAI manual but it sits on the shelf, along with the
      > other original manuals I have. I almost exclusively rely on the PDF scans I
      > made because it's easier and I don't have to worry about spilling coffee or
      > whatever on them. I could use a new IMSAI binder, thoughŠmine is dogged.
      >
      > Good luck. If you look on my IMSAI page, I have a write-up describing how I
      > got CP/M running on my IMSAI.
      >
      > Rich
      >
      > --
      > Rich Cini
      > Collector of Classic Computers
      > Build Master and lead engineer, Altair32 Emulator
      > http://www.classiccmp.org/cini
      > http://www.classiccmp.org/altair32
      >
      >
      > From: josh6502 <no_reply@yahoogroups.com>
      > Reply-To: "midatlanticretro@yahoogroups.com"
      > <midatlanticretro@yahoogroups.com>
      > Date: Fri, 16 Mar 2012 01:25:13 +0000
      > To: "midatlanticretro@yahoogroups.com" <midatlanticretro@yahoogroups.com>
      > Subject: [midatlanticretro] Re: IMSAI front panel ECO question
      >
      >
      >
      >
      >
      >
      > I wish I could share these schematics. They look great in color. I printed
      > them up on 17x22 paper for my old eyes. I even verified them net by net
      > against my boards. The funny part, was that I bought the reprinted version
      > of the IMSAI manual for the purpose of having a semi-original manual. The
      > thought of putting these new schematics in this manual never entered my mind
      > because I want the manual to remain as original as possible (for something
      > that's been reprinted years later).
      >
      > But I'm a little confused about something. Wasn't the IMSAI all about and
      > for sharing of technology? Isn't that why they duplicated the Altair Bus?
      >
      > Maybe Todd didn't like the schematics because it was missing the copywrite
      > information, which I just thought would be added later. And now that I
      > think about it, notes can be added to indicate these aren't the original
      > schematics etc... Isn't imitation the sincerest form of flattery?
      >
      > Well, onto my next project... time to get this old beastie to run CP/M.
      >
      > Wish me luck!
      >
      > --- In midatlanticretro@yahoogroups.com
      > <mailto:midatlanticretro%40yahoogroups.com> , Richard Cini <rich.cini@>
      > wrote:
      > >
      > > Ok, I understand Todd's point and agree that historical authenticity is
      > > important, but only to a point. My primary concern is keeping these old
      > > beasts running as best as they can rather than a working museum display
      > > where authenticity would be more important.
      > >
      > > There have been a few times that I've tried to use a poor copy of a
      > > schematic or a manual in order to troubleshoot and/or repair one of my
      > > boards and I would have given almost anything for a readable copy. I muddle
      > > through, but it's not fun at all.
      > >
      > > Rich
      > >
      > > --
      > > Rich Cini
      > > Collector of Classic Computers
      > > Build Master and lead engineer, Altair32 Emulator
      > > http://www.classiccmp.org/cini
      > > http://www.classiccmp.org/altair32
      > >
      > >
      > > From: josh6502 <no_reply@yahoogroups.com <mailto:no_reply%40yahoogroups.com>
      > >
      > > Reply-To: "midatlanticretro@yahoogroups.com
      > <mailto:midatlanticretro%40yahoogroups.com> "
      > > <midatlanticretro@yahoogroups.com <mailto:midatlanticretro%40yahoogroups.com>
      > >
      > > Date: Thu, 15 Mar 2012 00:12:41 +0000
      > > To: "midatlanticretro@yahoogroups.com
      > <mailto:midatlanticretro%40yahoogroups.com> " <midatlanticretro@yahoogroups.com
      > <mailto:midatlanticretro%40yahoogroups.com> >
      > > Subject: [midatlanticretro] Re: IMSAI front panel ECO question
      > >
      > >
      > >
      > >
      > >
      > >
      > > I found the original schematic to be poorly drawn so I took the time to
      > > redraw the schematic and compare it against my board and the ECO's. I added
      > > lots of notes to explain the logic at various points and some color to make
      > > it easy to follow. I wish I could share it but Thomas Fischer believes
      > > redrawn schematics diminish the originality of the product. So he will not
      > > support redistribution of this drawing. Since I've drawn the schematic
      > > primarily from his original schematic, I can't say it's mine. And just the
      > > same, I must agree with Thomas, the original schematics give it a nice
      > > 1970's feel.
      > >
      > > --- In midatlanticretro@yahoogroups.com
      > <mailto:midatlanticretro%40yahoogroups.com>
      > > <mailto:midatlanticretro%40yahoogroups.com> , Dan Roganti <ragooman@>
      > > wrote:
      > > >
      > > > On Sun, Feb 26, 2012 at 8:09 PM, Richard Cini <rich.cini@> wrote:
      > > >
      > > > >
      > > > >
      > > > > Bill --
      > > > >
      > > > > Ok, maybe there are different versions of the rev.4 schematics floating
      > > > > around. For example, my schematic shows the 76-0061 ECO hand-drawn on it,
      > > > > but none of the other changes. My schematic is dated "Rev.4 2/27/76". If
      > > > > this is right, then it wouldn't show any of the later ECOs.
      > > > >
      > > >
      > > >
      > > > Mine doens't have any of the ECO's hand drawn on it either. I just knew it
      > > > have the STOP mode ECO from the last time I had it disassembled.
      > > >
      > > >
      > > >
      > > >
      > > > >
      > > > > If you have a later version of the schematic that shows all of the ECOs,
      > > > > I'd like a copy. The version I have came with my IMSAI and there doesn't
      > > > > appear to be a version on IMSAI.net for download for me to cross-reference
      > > > > against.
      > > > >
      > > > >
      > > > I have seen any newer version of the CPA schematic yet either.
      > > >
      > > > =Dan
      > > >
      > >
      >
    • Show all 16 messages in this topic