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26141Re: Booting a NorthStar Horizon

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  • wb4jfi
    Jun 9, 2012
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      Herb:

      I will contact you separately as well, but I can report that I have very successfully punched both 5-1/4 N* and regular 8-inch CP/M floppy disks and used both sides (single density). There were brands that this was a good practice with, and brands that were bad. Memorex were bad, 3M and Verbatim were OK, for example.

      One issue was that you needed to make sure that the felt pad opposite the head was clean and in good shape. Otherwise, you ended up with scratches which did not affect the "main" side, but could cause severe problems when flipped to the head.

      I made a small spatula-like thing from a business card, by cutting one long-edge into a rounded end. Next, I flipped a regular floppy upside down (after finding the index hole), and marking the place to punch on the target envelope with a Sharpie. Do this on both sides of the target floppy. Then, carefully put the rounded end of the business card betweem the envelope and the media (through the large center hole), to make a space between them. Punch the new hole where marked using a small, single-hole paper punch, while making sure the business card is between the metal punch and the media itself. The business card prevents the metal punch from scratching the media. I used to boxes at a time while watching TV. Now, I would have done it while waiting for a Windows machine to boot (ha ha).

      As of two years ago, many of my "punched" 8-inch single-density 241k CP/M disks were still readable, even after almost 30 years. I don't have a N* system, so I can't authentiate those disks anymore.

      My biggest problem with my main CP/M system is the old Tarbell whack-the-media-during-power-up syndrome. I've destroyed more disks by forgetting to open the drive door before powering up the IMSAI. Then, upon power-up, I hear that sickening clank, and I know another CP/M boot floppy has bit the dust...
      Terry, WB4JFI

      --- In midatlanticretro@yahoogroups.com, "s100doctor" <hjohnson@...> wrote:
      >
      > For those who posted "Herb will chime in"...I don't follow this mail list daily. If you think someone should contact me, please refer them to my Web site so they can do that. I have a specific Web page on Northstar, for instance, that would be a good link to have offered Kyle.
      >
      > Kyle, about your "northstar" system. With S-100 computers, you won't know what you have until you survey the cards. Now that you've done so, I can see it's mostly "Northstar".
      >
      > Northstar made floppy controllers as their first product, then offered whole systems. The Northstar Horizon (S-100 system) was pretty popular so there's a lot of these around. Almost all Northstar stuff used "hard sectored" diskettes, as discussed, including yours. It's 10 sector holes plus an eleventh hole as the "index". Look up "hard sectored floppy" on the Web to learn what that's about. By the way, that "10" is what Bill Degnan was probably talking about, OK?
      >
      > Kyle, you can't write to hard-sectored disks with a modern computer, not even one with a 5.25-inch drive. You'll have to find someone with a Northstar Horizon, to make you a "boot disk". The Horizons ran either NorthStar DOS, or CP/M. Contact me c/o my retrotechnology.com Web site to get a CP/M N* boot disk from me, for a modest fee. (there's an alternative way to create a bootable disk but you won't likely need to do that.) There's many N* owners around, welcome to the club!
      >
      > There's talk about "punching your own disks". Could someone who has actually SUCCEEDED in punching their own disks and producing USABLE disks, please contact me? All I've heard is negative reports. 10-sector hard sectored disks sometimes are sold on eBay, or ask around for them. I don't have many to offer right now.
      >
      > Documentation for the N* is readily available on on-line archives. "northstar horizon manuals" in Google will find them. You may find my Web page of manuals too, that way. Check my list of docs on my site, for ones that may not be available on line (mine are off-line, no apologies). I find it awkward to have to explain that reading a manual is important, and why, in the 21st century. So I'll put it this way: I'll insist on it, if you contact me more than a few times.
      >
      > I've found the N* Horizons to be fairly easy to get back into service. If your machine is working, on reset (the red toggle switch in the back), one of the two floppy drives should start rotating and light up, for many seconds, then stop if there's no diskette. Clean the heads on your floppy drives and if you can, remove the drives and verify the drives on another machine. It would be sad if your drives had dirty heads, and the crap on the head scraped off the magnetic coating on your only boot diskette. Yes, that happens.
      >
      > There's all sorts of things one can do to restore one of these systems. I discuss things I and others have done, on my Web site's "restoration" pages at:
      >
      > http://www.retrotechnology.com/restore/r_restore.html
      >
      > My Northstar manuals list and some N* discussion is at
      >
      > http://www.retrotechnology.com/herbs_stuff/d_nstar.htm
      >
      > Floppy disk hard sector stuff (and other details) is at
      >
      > http://www.retrotechnology.com/herbs_stuff/drive.html#facts
      >
      > I'll let my Web pages do the talking from here.
      >
      > Herb
      >
      >
      > --- In midatlanticretro@yahoogroups.com, Kyle Owen <kylevowen@> wrote:
      > >
      > > I got a chance to look at the N* again today. It looks like the disk
      > > controller is an MDS-AD3, from N*. Also installed is a CompuKit Econoram
      > > VII A board, with one of the 5 of the 6 rows of RAM fully populated.
      > > There's also a N* 16k RAM board, and the processor card, a ZPB-A2. The
      > > floppy drives are made by Tandon, and are both TM101-4s.
      > >
      > > I can't find too much info the particular floppy controller, other than
      > > that it appears to be a double-density unit. I suppose it's still using
      > > hard sectors.
      > >
      > > 73,
      > >
      > > Kyle
      > >
      >
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