Re: Looking for a document regarding PDP8
At 10:00 AM 4/17/2020, Bob Smith wrote: ...I believe sometime in the late 70s, maybe as late as 1980, a prof associated with UMass wrote a paper describing an extension of the PDP8 called 8/X or 8X. ...I believe, my memory is fuzzy, that it was a prof nnmed Stone or Stoner (perhaps Harold S) who lead the effort and had his name on the paper. That is probably Harold S. Stone, whom I knew as a Stanford prof in the early 1970s and did some corporate consulting with. Brilliant guy. From 1974 to 1984 he was at UMass Amherst, so your memory isn't fuzzy at all. He also worked at the IBM Yorktown Heights research center. He was the author of several books and many papers about computer architecture, algorithms, and interfaces. Unfortunately I don't remember him working on a PDP-8 extension, and a quick search of the ACM Digital Library turned up nothing. As far as I know he's still alive at the age of 82.
Eudora email client source code released
For the last five years I've been working with Qualcomm and others to allow the Computer History Museum to release the source code of what was, in my opinion, the finest email client ever written: Eudora. It's finally done! http://www.computerhistory.org/atchm/the-eudora-email-client-source-code/
Re: Reading MT/ST tapes
Date: Wed, 28 Jul 2021 18:37:17 -0500 From: Cory Heisterkamp This is a bit of a long shot, but is anyone aware of a successful method to read IBM Selectric MT/ST tapes? A museum in Australia has a box of them and are interested in the contents. At the Computer History Museum we sometimes use a software technique to recover data from the analog waveforms on mag tapes. https://github.com/LenShustek/readtape I'd like to try that on MT/ST tapes. Does anyone have a couple of MT/ST tape cartridges with data that I can experiment with?
Re: Help reading a 9 track tape
> On Aug 5, 2021, at 8:39 AM, Jay Jaeger via cctech wrote: > I know Paul well (we were contemporaries at U. WI). He does not do that very often. He did not indicate any issue with a fire at the building that contains his collection when I last spoke with him. > > He does not actually read "blocks". He reads the tape in an *analog* fashion, and then processes the results with software. That is how he recovered the IBM 1410 system tapes and diagnostics, for example. > > To be honest, I doubt that this content would be such that he would be likely to volunteer. Some years ago, inspired by Paul Pierce's earlier program in Java, I wrote similar software in C to decode the analog waveforms from tapes in a variety of formats: 7-track NRZI, 9-track NRZI, PE, and 6250 BPI GCR, and 6-track NRZI for Whirlwind. https://github.com/LenShustek/readtape As a one-time physics major, I *am* interested in the Schoonschip content. I've offered to James Liu to give it a go if he can't get someone like Chuck to read it in a more straightforward fashion.
[cctalk] Re: IBM 727 tape drive
At Mon, 18 Sep 2023 10:55:13 +0200 (CEST) Christian Corti wrote: as it will be soon of importance to us, I am seeking for the systems engineering manual and drawings, well, everything about the IBM 727 tape drive (not the 729!). I especially need the module locations charts and the module schematics. Just a few weeks ago I donated to the Computer History Museum a set of 14 original IBM black binders of "Type 7xx" manuals from the 1950s, including the 727. That one is likely to be the same as what's on bitsavers, but since it's no longer in hand I can't check. They probably haven't made it through the CHM cataloging process yet.
[cctalk] Free Fujitsu M2444 6250 BPI tape drive
I bought this giant GCR tape drive on eBay five years ago, http://www.bitsavers.org/pdf/fujitsu/_brochures/M244X_Brochure_1984.pdf hoping to be able to use it to extract analog signals from 6250 BPI tapes to feed into my decoding program. https://github.com/LenShustek/readtape I failed to figure out how to get the right signals out, and eventually abandoned the project. I now need the space it takes, so I'm offering it for free before consigning it to the landfill. It's big (20" x 24" x 30" on the wheeled stand I built) and heavy (160 lbs) so I won't ship it. Pickup only, on the San Francisco peninsula.
[cctalk] Re: Free Fujitsu M2444 6250 BPI tape drive
The drive is saved from the landfill! It was picked up by a classic computing fan at noon this morning. (And yes, it is Pertec-compatible.)
[cctalk] Re: Odd IBM mass storage systems
At 10:00 AM 4/13/2024, Paul Berger wrote: The problem with a lot of these old machines was they relied on a lot of electro-mechanical devices that would today be replaced by electronics and a few simple actuators. These mechanical devices need to be adjusted and maintained and have lots of parts to wear out. For a great example of 1950s electro-mechanical devices, check out this: https://www.computerhistory.org/collections/catalog/102740072 https://www.computerhistory.org/collections/catalog/102740069 "The First Magnetic Random Access Mass Memory with Interchangeable Media"
