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Designing Vintage Hardware (was Altair 680 Basic - loading without papertape)

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  • David Comley
    ... I ve had several design needs for things over the years, the most recent being for MFM disk emulation running over IDE (subject of a recent thread here or
    Message 1 of 21 , May 4, 2007
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      --- Dan <ragooman@...> wrote:
      >
      > I always wondered if there was any need for
      > designing vintage hardware.

      I've had several design needs for things over the
      years, the most recent being for MFM disk emulation
      running over IDE (subject of a recent thread here or
      on cctalk).

      Dan, you'd mentioned a source for low-cost Atmel
      microcontroller boards last weekend. Could you provide
      the name of the supplier ? I really need to know if
      they have a low-cost development board. The stock
      development system runs over $1000 which is a little
      steep.

      -Dave
    • David Gesswein
      ... I didn t see the beginning of this thread but had noticed this one recently which looked nice and was thinking of using to upgrade my 8 controller when I
      Message 2 of 21 , May 4, 2007
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        > Dan, you'd mentioned a source for low-cost Atmel
        > microcontroller boards last weekend. Could you provide
        > the name of the supplier ?
        >
        I didn't see the beginning of this thread but had noticed this one
        recently which looked nice and was thinking of using to upgrade my 8
        controller when I retire the old machine which controls it now.

        http://www.digikey.com/scripts/us/dksus.dll?KeywordSearch?mpart=ATNGW100
        http://www.atmel.com/dyn/products/tools_card.asp?tool_id=4102

        If you want HW debugging you do need the more expensive ICE but I think can
        do printf's type debugging. Would need to check if you reflash with a bad
        load it leave enough loader around to reflash.
        http://www.digikey.com/scripts/us/dksus.dll?Criteria?Ref=7383&Site=US&Cat=35455746

        I used ATMEGA at work several years ago which had cheap boards
        available. We used the STK300 until our custom board was in. It is
        available from http://www.kanda.com/index.php3?cs=1& We used a
        commercial compiler but a gcc port is available,
        I just used printf's for debugging and jtag programmer for reflashing, not
        sure what the ICE they are including now does.
      • Dan
        Dave, MFM Emulation ? That project sounds interesting, for which machine is it ? Here s the one place I mentioned (both links points to their Atmel products)
        Message 3 of 21 , May 4, 2007
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          Dave,

          MFM Emulation ?
          That project sounds interesting, for which machine is it ?

          Here's the one place I mentioned (both links points to their Atmel products)
          http://microcontrollershop.com/default.php?cPath=110_159
          http://microcontrollershop.com/product_info.php?cPath=110_58&products_id=812

          =Dan


          [ My Corner of Cyberspace http://ragooman.home.comcast.net/ ]



          David Comley wrote:
          >
          > --- Dan <ragooman@... <mailto:ragooman%40comcast.net>> wrote:
          > >
          > > I always wondered if there was any need for
          > > designing vintage hardware.
          >
          > I've had several design needs for things over the
          > years, the most recent being for MFM disk emulation
          > running over IDE (subject of a recent thread here or
          > on cctalk).
          >
          > Dan, you'd mentioned a source for low-cost Atmel
          > microcontroller boards last weekend. Could you provide
          > the name of the supplier ? I really need to know if
          > they have a low-cost development board. The stock
          > development system runs over $1000 which is a little
          > steep.
          >
          > -Dave
          >
          >
          > ------------------------------------------------------------------------
          >
          > No virus found in this incoming message.
          > Checked by AVG Free Edition.
          > Version: 7.5.467 / Virus Database: 269.6.2/787 - Release Date: 5/3/2007 2:11 PM
          >
        • David Comley
          ... Well, pretty much any machine I think, although I m targetting DEC hardware (VAXen and Professional 350 systems) initially where an RD5X drive would be
          Message 4 of 21 , May 4, 2007
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            --- Dan <ragooman@...> wrote:
            > MFM Emulation ?
            > That project sounds interesting, for which machine
            > is it ?
            >
            Well, pretty much any machine I think, although I'm
            targetting DEC hardware (VAXen and Professional 350
            systems) initially where an RD5X drive would be
            expected.

            I'm hoping to be able to emulate a Micropolis 1325 at
            a low enough level that it could support any
            host/controller platform (that can use that particular
            drive type/geometry etc). The drive emulation should
            be transparent to the point where any low level format
            can be overlaid on it by the controller or host.

            Doing an emulation of an MFM drive would be useful for
            a variety of reasons for hobbyists, not the least of
            which is the cost of replacement drives. The MTTF of
            the platters in these drives is 4 years so they are a
            dying breed; plus, emulation would make it possible to
            expose the low-level formatting used by the hardware
            vendor, something that there's not a great deal of
            documentation on so far as I can tell.

            Of course talking about it is easier than actually
            doing it...

            -Dave
          • Dan
            Mike, I like the stuff on your website. I m thinking more about this too. I just don t know if I can bring myself again to wiring 2102 s in a row just to make
            Message 5 of 21 , May 4, 2007
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              Mike,

              I like the stuff on your website. I'm thinking more about this too. I
              just don't know if I can bring myself again to wiring 2102's in a row
              just to make 4KB of memory. It's real easy to add 64KB of memory on one
              S-100 card. It's not exactly using vintage components, but being that
              it's within the confines of a vintage form factor(S-100) and machines,
              maybe that doesn't tarnish the retro factor. I see there's still some
              activity on the vintage-computer.com forum about making S-100 boards.

              =Dan.

              [ My Corner of Cyberspace http://ragooman.home.comcast.net/ ]



              Bob Applegate wrote:
              >
              > [snip]
              > I keep toying with the idea of building new S-100 cards since used
              > ones on eBay go for so much and always carry no guarantee. While not
              > truly vintage, it
              > is "vintage-like" because old components are used. From the software
              > perspective, it IS
              > vintage... old CPUs that you've got to write a bootstrap for, etc.
              >
              > Bob
              >
              >
              >
            • B. Degnan
              I can t remember if I replied to this message. No he has not finished.
              Message 6 of 21 , May 5, 2007
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                I can't remember if I replied to this message. No he has not finished.

                At 07:24 PM 5/3/2007 -0400, you wrote:

                >I always wondered if there was any need for designing vintage hardware.
                >I have everything here to design and test just about any hardware.
                >
                >I haven't heard from Grant yet if he has finished the 680 memory card yet.
                >
                >=Dan
              • B. Degnan
                ... There is nothing wrong with putting non-vintage hardware in a vintage machine IMHO. From a testing perspective new parts can be the key to diagnosing
                Message 7 of 21 , May 5, 2007
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                  <snip>
                   
                  I won't retire off selling add-ons for old machines, but I get a lot of neat stories from
                  people about their old machines.  I also get a fair amount of vintage equipment offered
                  to me since clearly I care about that older stuff.  It's fun.
                   
                  My boards are for the KIM-1, which was produced in fairly large quantities compared to
                  some other systems.  I keep toying with the idea of building new S-100 cards since used
                  ones on eBay go for so much and always carry no guarantee.  While not truly vintage, it
                  is "vintage-like" because old components are used.  From the software perspective, it IS
                  vintage... old CPUs that you've got to write a bootstrap for, etc.
                   
                  Bob
                   

                  There is nothing wrong with putting non-vintage hardware in a vintage machine IMHO.  From a testing perspective new parts can be the key to diagnosing vintage part problems.  You can compare and contrast the vintage part with the new part to troubleshoot.  When it's time for an exhibit, swap the vintage part back into the system.
                • Evan Koblentz
                  Who s Mike? ... From: Dan [mailto:ragooman@comcast.net] Sent: Friday, May 04, 2007 11:59 PM To: midatlanticretro@yahoogroups.com Subject: Re:
                  Message 8 of 21 , May 5, 2007
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                    Who's Mike?


                    -----Original Message-----
                    From: Dan [mailto:ragooman@...]
                    Sent: Friday, May 04, 2007 11:59 PM
                    To: midatlanticretro@yahoogroups.com
                    Subject: Re: [midatlanticretro] Altair 680 Basic - loading without
                    papertape

                    Mike,

                    I like the stuff on your website. I'm thinking more about this too. I
                    just don't know if I can bring myself again to wiring 2102's in a row
                    just to make 4KB of memory. It's real easy to add 64KB of memory on one
                    S-100 card. It's not exactly using vintage components, but being that
                    it's within the confines of a vintage form factor(S-100) and machines,
                    maybe that doesn't tarnish the retro factor. I see there's still some
                    activity on the vintage-computer.com forum about making S-100 boards.

                    =Dan.

                    [ My Corner of Cyberspace http://ragooman.home.comcast.net/ ]



                    Bob Applegate wrote:
                    >
                    > [snip]
                    > I keep toying with the idea of building new S-100 cards since used
                    > ones on eBay go for so much and always carry no guarantee. While not
                    > truly vintage, it
                    > is "vintage-like" because old components are used. From the software
                    > perspective, it IS
                    > vintage... old CPUs that you've got to write a bootstrap for, etc.
                    >
                    > Bob
                    >
                    >
                    >



                    Yahoo! Groups Links
                  • Dan
                    oops, neural glitch that was supposed to be *Bob Applegate s *website [ My Corner of Cyberspace http://ragooman.home.comcast.net/ ]
                    Message 9 of 21 , May 5, 2007
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                      oops, neural glitch

                      that was supposed to be *Bob Applegate's *website

                      [ My Corner of Cyberspace http://ragooman.home.comcast.net/ ]



                      Evan Koblentz wrote:
                      >
                      > Who's Mike?
                      >
                      >
                    • Bob Applegate
                      ... No offense was taken, I assure you! Bob/Mike/whatever ___________________________________ NOCC, http://nocc.sourceforge.net
                      Message 10 of 21 , May 5, 2007
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                        Dan <ragooman@...> wrote :

                        > oops, neural glitch
                        >
                        > that was supposed to be *Bob Applegate's *website

                        No offense was taken, I assure you!

                        Bob/Mike/whatever


                        ___________________________________
                        NOCC, http://nocc.sourceforge.net
                      • Bob Applegate
                        I meant non-vintage as-in using more current parts, such as any of the 64Kx8 RAM chips out there. I d never resort to 2102s again! 2114s, maybe (1Kx4 bits).
                        Message 11 of 21 , May 5, 2007
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                          I meant non-vintage as-in using more current parts, such as
                          any of the 64Kx8 RAM chips out there. I'd never resort to
                          2102s again! 2114s, maybe (1Kx4 bits). Another example is
                          using a small CPLD instead of lots of discrete TTL. The
                          CPLD is cheaper, more flexible, easier to debug, but definitely
                          not a 1970s device.

                          I don't know that the 680's expansion pins are, but you can
                          probably add 64K of RAM with just a couple of parts now if
                          you're willing to veer away from pure vintage. The software
                          you run is still vintage, as is the base machine, and that's
                          the important part from my viewpoint. My KIM-1s are all
                          vintage, but I use newer parts to enhance them.

                          Bob

                          B. Degnan <billdeg@...> wrote :

                          > <snip>
                          >  
                          > I won't retire off selling add-ons for old machines, but I
                          > get a lot of neat stories from
                          > people about their old machines.  I also get a fair
                          > amount of vintage equipment offered
                          > to me since clearly I care about that older stuff. 
                          > It's fun.
                          >  
                          > My boards are for the KIM-1, which was produced in fairly
                          > large quantities compared to
                          > some other systems.  I keep toying with the idea of
                          > building new S-100 cards since used
                          > ones on eBay go for so much and always carry no
                          > guarantee.  While not truly vintage, it
                          > is "vintage-like" because old components are
                          > used.  From the software perspective, it IS
                          > vintage... old CPUs that you've got to write a bootstrap
                          > for, etc.
                          >  
                          > Bob
                          >  
                          > There is nothing wrong with putting non-vintage hardware in a vintage
                          > machine IMHO.  From a testing perspective new parts can be the key
                          > to diagnosing vintage part problems.  You can compare and contrast
                          > the vintage part with the new part to troubleshoot.  When it's time
                          > for an exhibit, swap the vintage part back into the system.
                          >
                          >
                          >
                          >
                          >

                          ___________________________________
                          NOCC, http://nocc.sourceforge.net
                        • Bryan Pope
                          ... Hey... I just used a few 2114 s to repair a couple of C= 4040 drives I have. :) ... There is quite a few people remaking vintage hardware using FPGA type
                          Message 12 of 21 , May 5, 2007
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                            Bob Applegate wrote:
                            > I meant non-vintage as-in using more current parts, such as
                            > any of the 64Kx8 RAM chips out there. I'd never resort to
                            > 2102s again! 2114s, maybe (1Kx4 bits). Another example is
                            >
                            Hey... I just used a few 2114's to repair a couple of C= 4040 drives I
                            have. :)

                            > using a small CPLD instead of lots of discrete TTL. The
                            > CPLD is cheaper, more flexible, easier to debug, but definitely
                            > not a 1970s device.
                            >
                            >
                            There is quite a few people remaking vintage hardware using FPGA type
                            devices like here: http://home.freeuk.com/fpgaarcade/

                            Cheers,

                            Bryan

                            > I don't know that the 680's expansion pins are, but you can
                            > probably add 64K of RAM with just a couple of parts now if
                            > you're willing to veer away from pure vintage. The software
                            > you run is still vintage, as is the base machine, and that's
                            > the important part from my viewpoint. My KIM-1s are all
                            > vintage, but I use newer parts to enhance them.
                            >
                            > Bob
                            >
                            >
                          • Dan
                            I started designing a S-100 layout this past weekend to make some memory cards. I was going to try both, one with vintage components and one using new
                            Message 13 of 21 , May 7, 2007
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                              I started designing a S-100 layout this past weekend to make some memory
                              cards. I was going to try both, one with vintage components and one
                              using new components. Istill have to pick a reasonable PCB house to make
                              the cards. I found a couple of places that still sell the S-100 edge
                              connectors so I was going to look into making the extender card for the
                              Altair680(it's the same connector--different pinout)

                              =Dan

                              [ My Corner of Cyberspace http://ragooman.home.comcast.net/ ]



                              Bryan Pope wrote:
                              >
                              > Bob Applegate wrote:
                              > > I meant non-vintage as-in using more current parts, such as
                              > > any of the 64Kx8 RAM chips out there. I'd never resort to
                              > > 2102s again! 2114s, maybe (1Kx4 bits). Another example is
                              > >
                              > Hey... I just used a few 2114's to repair a couple of C= 4040 drives I
                              > have. :)
                              >
                              > > using a small CPLD instead of lots of discrete TTL. The
                              > > CPLD is cheaper, more flexible, easier to debug, but definitely
                              > > not a 1970s device.
                              > >
                              > >
                              > There is quite a few people remaking vintage hardware using FPGA type
                              > devices like here: http://home.freeuk.com/fpgaarcade/
                              > <http://home.freeuk.com/fpgaarcade/>
                              >
                              > Cheers,
                              >
                              > Bryan
                              >
                              > > I don't know that the 680's expansion pins are, but you can
                              > > probably add 64K of RAM with just a couple of parts now if
                              > > you're willing to veer away from pure vintage. The software
                              > > you run is still vintage, as is the base machine, and that's
                              > > the important part from my viewpoint. My KIM-1s are all
                              > > vintage, but I use newer parts to enhance them.
                              > >
                              > > Bob
                              > >
                              > >
                              >
                              >
                              > ------------------------------------------------------------------------
                              >
                              > No virus found in this incoming message.
                              > Checked by AVG Free Edition.
                              > Version: 7.5.467 / Virus Database: 269.6.4/790 - Release Date: 5/5/2007 10:34 AM
                              >
                            • B Degnan
                              Dan, Did you get your Altair 680 working? Bill ... -END-
                              Message 14 of 21 , May 7, 2007
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                                Dan,
                                Did you get your Altair 680 working?
                                Bill
                                >
                                > I started designing a S-100 layout this past weekend to make some memory
                                > cards. I was going to try both, one with vintage components and one
                                > using new components. Istill have to pick a reasonable PCB house to make
                                > the cards. I found a couple of places that still sell the S-100 edge
                                > connectors so I was going to look into making the extender card for the
                                > Altair680(it's the same connector--different pinout)
                                >
                                > =Dan
                                >
                                > [ My Corner of Cyberspace http://ragooman.home.comcast.net/ ]
                                >
                                >
                                >
                                > Bryan Pope wrote:
                                >>
                                >> Bob Applegate wrote:
                                >> > I meant non-vintage as-in using more current parts, such as
                                >> > any of the 64Kx8 RAM chips out there. I'd never resort to
                                >> > 2102s again! 2114s, maybe (1Kx4 bits). Another example is
                                >> >
                                >> Hey... I just used a few 2114's to repair a couple of C= 4040 drives I
                                >> have. :)
                                >>
                                >> > using a small CPLD instead of lots of discrete TTL. The
                                >> > CPLD is cheaper, more flexible, easier to debug, but definitely
                                >> > not a 1970s device.
                                >> >
                                >> >
                                >> There is quite a few people remaking vintage hardware using FPGA type
                                >> devices like here: http://home.freeuk.com/fpgaarcade/
                                >> <http://home.freeuk.com/fpgaarcade/>
                                >>
                                >> Cheers,
                                >>
                                >> Bryan
                                >>
                                >> > I don't know that the 680's expansion pins are, but you can
                                >> > probably add 64K of RAM with just a couple of parts now if
                                >> > you're willing to veer away from pure vintage. The software
                                >> > you run is still vintage, as is the base machine, and that's
                                >> > the important part from my viewpoint. My KIM-1s are all
                                >> > vintage, but I use newer parts to enhance them.
                                >> >
                                >> > Bob
                                >> >
                                >> >
                                >>
                                >>
                                >> ------------------------------------------------------------------------
                                >>
                                >> No virus found in this incoming message.
                                >> Checked by AVG Free Edition.
                                >> Version: 7.5.467 / Virus Database: 269.6.4/790 - Release Date: 5/5/2007
                                >> 10:34 AM
                                >>
                                >
                                >
                                >
                                > Yahoo! Groups Links
                                >
                                >
                                >
                                >


                                -END-
                              • Dan
                                oh, I still have about 20 sockets left to replace, it s such an arduous task. Something I do in between my other projects. I m hoping that I ll get it done
                                Message 15 of 21 , May 7, 2007
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                                  oh, I still have about 20 sockets left to replace, it's such an arduous
                                  task. Something I do in between my other projects. I'm hoping that I'll
                                  get it done once the S-100 boards I'm designing are built.
                                  In the meantime, I'm going to fire-up my IMSAI, (figuratively speaking)
                                  so I can get my S-100 stuff running and be ready to test the new memory
                                  card designs.

                                  =Dan

                                  [ My Corner of Cyberspace http://ragooman.home.comcast.net/ ]



                                  B Degnan wrote:
                                  >
                                  > Dan,
                                  > Did you get your Altair 680 working?
                                  > Bill
                                  >
                                  >
                                • Herb Johnson
                                  ... There was a recent discussion of MFM emulation in comp.os.cpm, where I participate. The discussion of vintage vs. modern design is also of interest
                                  Message 16 of 21 , May 8, 2007
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                                    David Comley <david_comley@...> wrote:
                                    >
                                    > I'm hoping to be able to emulate a Micropolis 1325 at
                                    > a low enough level that it could support any
                                    > host/controller platform (that can use that particular
                                    > drive type/geometry etc). The drive emulation should
                                    > be transparent to the point where any low level format
                                    > can be overlaid on it by the controller or host.
                                    >
                                    > Doing an emulation of an MFM drive would be useful for
                                    > a variety of reasons for hobbyists, not the least of
                                    > which is the cost of replacement drives. The MTTF of
                                    > the platters in these drives is 4 years so they are a
                                    > dying breed; plus, emulation would make it possible to
                                    > expose the low-level formatting used by the hardware
                                    > vendor, something that there's not a great deal of
                                    > documentation on so far as I can tell.
                                    >
                                    > Of course talking about it is easier than actually
                                    > doing it...
                                    >
                                    > -Dave

                                    There was a recent discussion of MFM "emulation" in comp.os.cpm, where
                                    I participate. The discussion of "vintage" vs. "modern" design is also
                                    of interest to me. Here's my comments.

                                    In comp.os.cpm, it was noted that there WAS a MFM to IDE product, but
                                    it waa a few thousand dollars. Seems to me that one reason it is that
                                    high, is that it takes some bit of effort to support the variety of
                                    potential uses for such a product. Those who really need an MFM
                                    replacement, to keep production equipment going, will pay accordingly.

                                    The drive issue as cast in comp.os.cpm was about replacing an MFM
                                    drive in a S-100 system. It was suggested the owner use an IDE card of
                                    some sort, and write a driver. In some number of cases, it's more
                                    reasonable to replace the controller and adjust the software.

                                    The point of S-100 systems with a standard bus, was that you COULD
                                    replace and upgrade as needed. At least the hardware did not stop you
                                    from doing so. That concept spawned a computer industry from 1976
                                    through the 1980's. The IBM PC, to compete, HAD to offer 1) a bus and
                                    2) clear means to add to that bus - because S-100 and other systems
                                    set that standard. (In the minicomputer world, DEC set a similar
                                    standard as did other manufacturers.)

                                    In that light, there's been discussion here about building "new" S-100
                                    cards with either "vintage" hardware or with "new" hardware. Clearly
                                    an MFM to IDE device would be "new". It would require somewhat fast
                                    logic: either a programmable logic device, or a "computer on a
                                    board".

                                    But an IDE interface for S-100 or any Z80? - dirt simple, the IDE
                                    drive does all the work, just a few simple chips will do it (Google
                                    "GIDE"). But most people get stuck at the point where they have to
                                    write software to support that new device. (I should know, I first
                                    offered the GIDE interface in the USA, and I've watched its use.)

                                    Note to "purists" that say a vintage system has to have "original",
                                    vintage cards. Few REAL S-100 systems were "original", or stayed
                                    original. People upgraded as hardware improved, as software changed.

                                    The point? As I see it, if you are "into" old computers to show them
                                    off in original condiiton, then all this talk about "emulators" is
                                    moot. Pay $$$ for the last unused (or rebuilt) MFM hard drive and run
                                    it only on exhibit day. If you are in it because you can "dig into"
                                    it, then adapt some new hardware to old and start writing some CODE.
                                    If you are in it for "use" only, then you depend on others to keep
                                    providing working hardware: that, and your budget.

                                    Herb Johnson

                                    Herbert R. Johnson, New Jersey USA
                                    <a href="http://www.retrotechnology.com/herbs_stuff/"> web site</a>
                                    <a href="http://www.retrotechnology.net/herbs_stuff/"> domain mirror</a>
                                    my email address: hjohnson AAT retrotechnology DOTT com
                                    if no reply, try in a few days: herbjohnson ATT comcast DOTT net
                                    "Herb's Stuff": old Mac, SGI, 8-inch floppy drives
                                    S-100 IMSAI Altair computers, docs, by "Dr. S-100"
                                  • Jim Scheef
                                    Herb, Words of wisdom! As you note there is more than one way to enjoy vintage computing. Jim ... From: Herb Johnson To:
                                    Message 17 of 21 , May 8, 2007
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                                      Herb,

                                      Words of wisdom! As you note there is more than one way to enjoy 'vintage' computing.

                                      Jim

                                      ----- Original Message ----
                                      From: Herb Johnson <hjohnson@...>
                                      To: midatlanticretro@yahoogroups.com
                                      Sent: Tuesday, May 8, 2007 2:36:33 PM
                                      Subject: [midatlanticretro] Re: Designing Vintage Hardware (was Altair 680 Basic - loading without paperta

                                      David Comley <david_comley@ ...> wrote:

                                      >
                                      > I'm hoping to be able to emulate a Micropolis 1325 at
                                      > a low enough level that it could support any
                                      > host/controller platform (that can use that particular
                                      > drive type/geometry etc). The drive emulation should
                                      > be transparent to the point where any low level format
                                      > can be overlaid on it by the controller or host.
                                      >
                                      > Doing an emulation of an MFM drive would be useful for
                                      > a variety of reasons for hobbyists, not the least of
                                      > which is the cost of replacement drives. The MTTF of
                                      > the platters in these drives is 4 years so they are a
                                      > dying breed; plus, emulation would make it possible to
                                      > expose the low-level formatting used by the hardware
                                      > vendor, something that there's not a great deal of
                                      > documentation on so far as I can tell.
                                      >
                                      > Of course talking about it is easier than actually
                                      > doing it...
                                      >
                                      > -Dave

                                      There was a recent discussion of MFM "emulation" in comp.os.cpm, where
                                      I participate. The discussion of "vintage" vs. "modern" design is also
                                      of interest to me. Here's my comments.

                                      In comp.os.cpm, it was noted that there WAS a MFM to IDE product, but
                                      it waa a few thousand dollars. Seems to me that one reason it is that
                                      high, is that it takes some bit of effort to support the variety of
                                      potential uses for such a product. Those who really need an MFM
                                      replacement, to keep production equipment going, will pay accordingly.

                                      The drive issue as cast in comp.os.cpm was about replacing an MFM
                                      drive in a S-100 system. It was suggested the owner use an IDE card of
                                      some sort, and write a driver. In some number of cases, it's more
                                      reasonable to replace the controller and adjust the software.

                                      The point of S-100 systems with a standard bus, was that you COULD
                                      replace and upgrade as needed. At least the hardware did not stop you
                                      from doing so. That concept spawned a computer industry from 1976
                                      through the 1980's. The IBM PC, to compete, HAD to offer 1) a bus and
                                      2) clear means to add to that bus - because S-100 and other systems
                                      set that standard. (In the minicomputer world, DEC set a similar
                                      standard as did other manufacturers. )

                                      In that light, there's been discussion here about building "new" S-100
                                      cards with either "vintage" hardware or with "new" hardware. Clearly
                                      an MFM to IDE device would be "new". It would require somewhat fast
                                      logic: either a programmable logic device, or a "computer on a
                                      board".

                                      But an IDE interface for S-100 or any Z80? - dirt simple, the IDE
                                      drive does all the work, just a few simple chips will do it (Google
                                      "GIDE"). But most people get stuck at the point where they have to
                                      write software to support that new device. (I should know, I first
                                      offered the GIDE interface in the USA, and I've watched its use.)

                                      Note to "purists" that say a vintage system has to have "original",
                                      vintage cards. Few REAL S-100 systems were "original", or stayed
                                      original. People upgraded as hardware improved, as software changed.

                                      The point? As I see it, if you are "into" old computers to show them
                                      off in original condiiton, then all this talk about "emulators" is
                                      moot. Pay $$$ for the last unused (or rebuilt) MFM hard drive and run
                                      it only on exhibit day. If you are in it because you can "dig into"
                                      it, then adapt some new hardware to old and start writing some CODE.
                                      If you are in it for "use" only, then you depend on others to keep
                                      providing working hardware: that, and your budget.

                                      Herb Johnson

                                      Herbert R. Johnson, New Jersey USA
                                      <a href="http://www.retrotec hnology.com/ herbs_stuff/"> web site</a>
                                      <a href="http://www.retrotec hnology.net/ herbs_stuff/"> domain mirror</a>
                                      my email address: hjohnson AAT retrotechnology DOTT com
                                      if no reply, try in a few days: herbjohnson ATT comcast DOTT net
                                      "Herb's Stuff": old Mac, SGI, 8-inch floppy drives
                                      S-100 IMSAI Altair computers, docs, by "Dr. S-100"


                                    • David Comley
                                      Well said, Herb. Having met so many MARCH folks at TCF, I started to think again about my own take on the hobby. I d profile my own collection and activities
                                      Message 18 of 21 , May 9, 2007
                                      • 0 Attachment
                                        Well said, Herb.

                                        Having met so many MARCH folks at TCF, I started to
                                        think again about my own take on the hobby. I'd
                                        profile my own collection and activities as being
                                        discovery - or re-discovery - related, rather than
                                        restoration/refurbishment to original condition. Most
                                        of the things I've acquired are missing covers or have
                                        dings and dents, and nothing could be said to be 'New
                                        in Box' or even close. Instead, I spend a lot of time
                                        trying to understand how things were connected or
                                        configured together (and even what they were used
                                        for). That often results in repair work to return a
                                        system to a bootable state (or in a long wait while I
                                        scour hamfests and swap meets to find a missing board,
                                        cable or disk).

                                        It's a great hobby, isn't it: each of us derives
                                        satisfaction from it from pursuing a different aspect
                                        or perspective - and hopefully we contribute to a
                                        broader pool of knowledge by doing so. One can only
                                        hope that we capture that knowledge somehow for
                                        posterity and the next generation of enthusiasts.

                                        -Dave

                                        --- Herb Johnson <hjohnson@...> wrote:

                                        > Note to "purists" that say a vintage system has to
                                        > have "original",
                                        > vintage cards. Few REAL S-100 systems were
                                        > "original", or stayed
                                        > original. People upgraded as hardware improved, as
                                        > software changed.
                                        >
                                        > The point? As I see it, if you are "into" old
                                        > computers to show them
                                        > off in original condiiton, then all this talk about
                                        > "emulators" is
                                        > moot. Pay $$$ for the last unused (or rebuilt) MFM
                                        > hard drive and run
                                        > it only on exhibit day. If you are in it because you
                                        > can "dig into"
                                        > it, then adapt some new hardware to old and start
                                        > writing some CODE.
                                        > If you are in it for "use" only, then you depend on
                                        > others to keep
                                        > providing working hardware: that, and your budget.
                                        >
                                        > Herb Johnson
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