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Re: [midatlanticretro] To change or not to change? Re: NorthStar Horizon Woes

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  • B. Degnan
    ... assume ... for ... directly ... I think you mean $E800, right? You don t want to cut off the MDA drive controller that uses $E000 bd
    Message 1 of 24 , Oct 17, 2012
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      >
      > Great post, Herb! I have taken your advice to heart. I'm modifying my
      > ZPB-2A board for a 2kB 2716 at $E000. I'll be booting to ROM in no time.
      > I'll document this and let you put it on your website for others, if you
      > want. It only requires one jumper and lifting a few pins. This would
      assume
      > a card that never had anything installed. Otherwise, quite a few things
      > would need to be removed, namely the -5V and 12V power supply sections
      for
      > the 2708. Else, just lift the A10 pin on your EPROM and solder it
      directly
      > to the ZA10 line.
      >
      > But I'll do a better write-up with pictures soon. That is, if it works!
      >
      > Kyle
      >

      I think you mean $E800, right? You don't want to cut off the MDA drive
      controller that uses $E000

      bd
    • Christian Liendo
      ... Christian Liendo likes this!
      Message 2 of 24 , Oct 17, 2012
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        >From: s100doctor <hjohnson@...>
        >Free your minds! of visions of eBay auctions of "mint" Altairs! You have nothing to lose but your chain-store computers! Go write some 8080 binary code! Burn some solder! Burn the EPROMS! Burn some electrolytics! Burn them all! Be like your predecessors. Make the world safe for personal computing again!


        Christian Liendo likes this!
      • Kyle Owen
        Well, the MDS floppy controller (which is what I have) uses an address of $E800, so I m going to use $E000 as the ROM address. I may bring out a switch to the
        Message 3 of 24 , Oct 17, 2012
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          Well, the MDS floppy controller (which is what I have) uses an address of $E800, so I'm going to use $E000 as the ROM address. I may bring out a switch to the rear of the computer to set the power-on jump address between those two, if it's not too difficult. Their space-saving address method would make for selecting addresses with switches on the back a bit more difficult. I think it can still be done, though.

          Kyle

          On Wed, Oct 17, 2012 at 7:52 AM, B. Degnan <billdeg@...> wrote:
           

          >
          > Great post, Herb! I have taken your advice to heart. I'm modifying my
          > ZPB-2A board for a 2kB 2716 at $E000. I'll be booting to ROM in no time.
          > I'll document this and let you put it on your website for others, if you
          > want. It only requires one jumper and lifting a few pins. This would
          assume
          > a card that never had anything installed. Otherwise, quite a few things
          > would need to be removed, namely the -5V and 12V power supply sections
          for
          > the 2708. Else, just lift the A10 pin on your EPROM and solder it
          directly
          > to the ZA10 line.
          >
          > But I'll do a better write-up with pictures soon. That is, if it works!
          >
          > Kyle
          >

          I think you mean $E800, right? You don't want to cut off the MDA drive
          controller that uses $E000

          bd


        • s100doctor
          In a few words, Mike is largely correct. There s a market for rare and pristine stuff, and such things should be kept in those conditions and restored with
          Message 4 of 24 , Oct 17, 2012
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            In a few words, Mike is largely correct. There's a market for rare and pristine stuff, and such things should be kept in those conditions and restored with care. And if one's interests are on those terms, more power to them.

            But a lot of S-100 computers (among others of the era) are NOT in those conditions, for the reasons I cited. They may not attract "collectable" interest, even if they are. But my interests, are in preserving and restoring hardware for USE, and in preserving the legacy of knowledge and experience of use, repair and restoration of computers of that pre-PC era.

            "Preservation" is an important point, here's why. A lot of 1970's and earlier knowledge will be lost, as guys like me and my older colleagues die, and their collections are disbursed. Common wisdom from journalists and writers in the 21st century about personal computing, is about the "winners" - Apple, IBM, Microsoft - and mostly of their 1980's efforts. (Apple I interests notwithstanding.) Before all that - ugly boxes of boards, from a handful of basement hobbyists, that ultimately didn't matter because they didn't become zillionaires. That's the view I'm fighting - that, and time itself.

            And so, "don't touch that" is antithetical to the spirit AND EXPERIENCE that started personal computing in the 1970's. Even the idea of repair itself, may be lost in the 21st century. That's my belief, that's what I'm responding to, and that's why I am hot about it. But there's certainly room for showcase vintage computing, it helps to start the conversation, to "pull" prices up and encourage interest. Mike, thanks for making your points.

            Herb Johnson

            --- In midatlanticretro@yahoogroups.com, Mike Willegal <mike@...> wrote:
            >
            > I'm all for using these computers, but if you have a pristine or very rare unit, any changes you make should be reversible. Collectors will always value these factory fresh units more than those that have been altered. Too much change, could significantly reduce value.
            >
            > If you have a rare or pristine unit, get it working, but don't modify. One option is to find another, less valuable machine that has already been altered to experiment with.
            >
            > My original Apple II and Mac 128k had a number of changes made to them back in the "old" days, some not reversible. I still have them, but wish I had them in factory new condition. However, I don't regret making the changes, cause that is what we did, back then.
            >
            >
            > Regards,
            > Mike W
            >
          • B. Degnan
            ... Horizon Woes ... of ... between ... Silly me, right. I got it backwards
            Message 5 of 24 , Oct 17, 2012
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              -------- Original Message --------
              > From: "Kyle Owen" <kylevowen@...>
              > Sent: Wednesday, October 17, 2012 12:45 PM
              > To: midatlanticretro@yahoogroups.com
              > Subject: Re: [midatlanticretro] To change or not to change? Re: NorthStar
              Horizon Woes
              >
              > Well, the MDS floppy controller (which is what I have) uses an address
              of
              > $E800, so I'm going to use $E000 as the ROM address. I may bring out a
              > switch to the rear of the computer to set the power-on jump address
              between
              > those two, if it's not too difficult. Their space-saving address method
              > would make for selecting addresses with switches on the back a bit more
              > difficult. I think it can still be done, though.
              >
              > Kyle
              >
              Silly me, right. I got it backwards
            • Systems Glitch
              ... Do it in software. You ll have plenty of room in that 2708, doubly so in a 16kbit device. I ve done a similar thing using the front panel sense switch
              Message 6 of 24 , Oct 17, 2012
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                > Well, the MDS floppy controller (which is what I have) uses an address of
                > $E800, so I'm going to use $E000 as the ROM address. I may bring out a
                > switch to the rear of the computer to set the power-on jump address between
                > those two, if it's not too difficult. Their space-saving address method
                > would make for selecting addresses with switches on the back a bit more
                > difficult. I think it can still be done, though.

                Do it in software. You'll have plenty of room in that 2708, doubly so in a 16kbit device. I've done a similar thing using the front panel sense switch register on my IMSAI.

                Thanks,
                Jonathan
              • Jim Scheef
                Yea Herb!
                Message 7 of 24 , Oct 17, 2012
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                  Yea Herb!


                  On 10/16/2012 7:28 PM, s100doctor wrote:
                   



                  It's funny to read these days, about concerns of "modifying the system from original", when talking about S-100 systems. It's funny to me, because quite simply, I was there at the time they were so-called "original".

                  People - like me - bought these old S-100 systems to USE, not to protect with plastic covers and never scratch them up. Most of these systems NEEDED upgrades, and required several different brands of cards, to eventually do something "standard". There really were NO STANDARDS, for many years.

                  And cards were bought as kits, bare boards. They were chopped up. That's why these systems had busses, dudes - for more cards! And often, old hardware was TERRIBLE - it had to be replaced. Some of it didn't even work when designed.

                  And then, there's today. Do you own one of these puppies to show off on a shelf? to sell on eBay? or to USE?

                  I say - put this old technology to USE!

                  Specific to this thread: "should I upgrade the Northstar CPU board with a ROM?" - SURE! Why NOT? You may have to modify the board a bit, to use a 5-volt only PROM, which will be easier to program. So WHAT? Build a little daughter card to plug in, if you don't want to hack the CPU board to death. That's why there are schematics, and manuals - to LEARN HOW TO MODIFY AND USE these boards!

                  Do it! Do it! Make it WORK! If it doesn't work, try something ELSE! If it breaks, FIX it!

                  USE, and mods, and different boards - that was the point of these S-100 systems. That's what was done in the era. That's what all those assemblers and compilers and editors were about. Protoboards, and boards with blank areas on them. All those ROMS! Those jumpers! Over 140 companies made S-100 cards. Why fuss so much, if your particular S-100 system isn't "standard"? ALMOST NONE OF THEM WERE. Especially the oldest S-100 systems, that most people talk about here.

                  If putting a ROM on a CPU board "breaks" NorthStar DOS, then figure out WHY! Read the manuals, the sources. Disassemble the binaries. Tear it all apart, and put it together again! WHY NOT?

                  That's what WE did, in the era! Before MS-DOS. Before "the Empire" of IBM and Microsoft. Before the "clone wars" of Taiwan PC's in the 1990's. Before Dell and HP and other megacorps, made PC's so powerful, they could finally run the crappiest, bloated, mind-numbingest OS's ever written.

                  Free your minds! of visions of eBay auctions of "mint" Altairs! You have nothing to lose but your chain-store computers! Go write some 8080 binary code! Burn some solder! Burn the EPROMS! Burn some electrolytics! Burn them all! Be like your predecessors. Make the world safe for personal computing again!

                  Happy Halloween,
                  Herb Johnson


                • joshbensadon
                  ... I don t know if it s so important to be able to reverse the change as much as it s to document it. When I applied all the latest ECO s to my IMSAI, I
                  Message 8 of 24 , Oct 17, 2012
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                    --- In midatlanticretro@yahoogroups.com, Mike Willegal <mike@...> wrote:
                    >
                    > I'm all for using these computers, but if you have a pristine or very rare unit, any changes you make should be reversible. Collectors will always value these factory fresh units more than those that have been altered. Too much change, could significantly reduce value.


                    I don't know if it's so important to be able to reverse the change as much as it's to document it. When I applied all the latest ECO's to my IMSAI, I didn't mind cutting traces and installing jumpers. When I built my Mark-8 Replica kit, I put away the original (dimm) LED's and replaced them with bright LED's because my enjoyment means more than an original (replica) system. I guess to each their own, but I believe toys are to be played with. I only hope I'll break even when I sell them one day.

                    :) Josh
                  • joshbensadon
                    ... I too get lots of satisfaction mastering and seeing these old beasts run. Part of it comes from trying to do the job while keeping it as original as
                    Message 9 of 24 , Oct 17, 2012
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                      --- In midatlanticretro@yahoogroups.com, "B. Degnan" <billdeg@...> wrote:
                      > Anyway, I personally got into vintage computing to learn more about
                      > electronics, and getting the systems to work is where I get the
                      > satisfaction, not so much whether I trashed the case or replaced a part to
                      > do it.

                      I too get lots of satisfaction mastering and seeing these old beasts run. Part of it comes from trying to do the job while keeping it as original as possible. When I had to fix some broken keys on my OSI Superboard, I wouldn't know where to get replacement switches, so I had to open them up to the point where I could fix it. I made a nice write up on that with lots of pictures and posted on one of the OSI web sites for the next guy.

                      Long live the Eureka Moment! When everything just starts to work again.

                      :) Josh
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