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Thread: trs80gp eumlator's floppy tape/stringy floppy-type wafers

  1. #1
    Join Date
    Sep 2009
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    Default trs80gp eumlator's floppy tape/stringy floppy-type wafers

    Has anyone tried or managed to extract information from a wafer without using a 'normal' drive?

  2. #2

    Default

    You mean a normal Stringy floppy drive Dusty? I don't know if it's ever been done but I can't imagine it would be easy.

    Tez
    ------------------------------------------------
    My vintage collection: https://classic-computers.org.nz/collection/
    My vintage activities blog: https://www.classic-computers.org.nz/blog/
    Twitter: @classiccomputNZ ; YouTube Videos: (click here)


  3. #3
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    Hi Tezza,
    yes, sorry, by 'normal' I meant a normal Aculab/Exatron wafer drive
    As you know, the system recorded, digitally, at, what then, a very fast baud rate of 6/7000! The 2mm wafers though, degraded easily in the day so time will have bee no help at all.
    I hoping to have a play (again) this weekend, just to see if I can get any successful 'READS' from my stock of wafers and dump to cassette any available software to use with George's FANTASTIC emulator.
    I remember, in the day, there were occasionally speed issues between Aculab drives when '@READ' was invoked.
    Wish me luck, I think I'll need it

  4. #4

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    Cheers Dusty,

    Don't forget I have a small archive site for digital images of Stringy Floppy programs. I'd love more!!
    https://www.classic-computers.org.nz...sf_archive.htm

    The images linked on the site are ones compatible with Matthew Reed's TRS32, which has ESF functonality.

    Tez
    ------------------------------------------------
    My vintage collection: https://classic-computers.org.nz/collection/
    My vintage activities blog: https://www.classic-computers.org.nz/blog/
    Twitter: @classiccomputNZ ; YouTube Videos: (click here)


  5. #5

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    P.S. I'm assuming you've seen this page too Dusty
    https://www.classic-computers.org.nz...ve-imaging.htm

    Tez
    ------------------------------------------------
    My vintage collection: https://classic-computers.org.nz/collection/
    My vintage activities blog: https://www.classic-computers.org.nz/blog/
    Twitter: @classiccomputNZ ; YouTube Videos: (click here)


  6. #6
    Join Date
    Jun 2010
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    Vancouver, BC, Canada
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    Default

    BTW, trs80gp only has Aculab floppy tape emulation and not yet Exatron Stringy Floppy.

  7. #7
    Join Date
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    Default

    Thanks Tezza, yes, I did get the details from your page some time ago. The problem I've always encountered is getting the wafers to @READ anything, ever
    I'm have a 'play' this weekend and hoping that it might be a tape-speed problem.
    I would just love to get a copy of Scripsit, Electric Pencil and ZEN editor/assembler working on George's emulator.

  8. #8
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    Has anyone thought about repopping stringy floppy wafers? Cutting magnetic tape (say high quality compact cassette tape) to the required 1.6mm width shouldn't be too difficult (eg. cutting tape for floppy drive belts) and the shells could perhaps be 3D printed. If any nylon rollers and such are in the wafer (I have not seen one for 30+ years) they could be machined up. If I had a wafer to examine and measure I reckon I'd give it a go.

  9. #9
    Join Date
    May 2018
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    Melbourne, Australia
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    Quote Originally Posted by Dustym View Post
    As you know, the system recorded, digitally, at, what then, a very fast baud rate of 6/7000! The 2mm wafers though, degraded easily in the day so time will have bee no help at all.
    My hypothesis is that the tape (substrate) doesn't actually lose tensile strength. My (untested) theory is that the lubricant on the tape fails and becomes sticky.

    Stringy floppy wafers are like 8 track tape cartridges - a continuous loop - and each wrap of tape in the tape pack needs to be able to slide in sheer relative to the layer above and below it in order to accommodate the difference in linear velocity between the outer layer of tape as it gets wrapped around the outside of the tape pack and where it is pulled from the inside of the pack near the hub.

    If the layers of tape can't slide then the tension will build up and break the tape - and specifically my theory is that the tension developed when you try and read the wafers today would also have broken the tapes when they were new.

    If the above is true then the solution is probably not to try and read the tapes in their current form with a normal drive. But if you do break them don't throw them away as the files are recorded in a linear fashion and files in unbroken sections could still potentially still be recovered if someone develops a new technique in the future.

  10. #10
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    For broken tapes, how about a 3D printed wafer-shaped special recovery cartridge that engages with the drive, but mostly hangs outside it. On that, a small vertical axis direct-drive DC motor and reel, speed adjustable to the capstan's speed. The external motor pulls the tape with its own capstan with a screw-adjustable tensioning arrangement. Perhaps a FET to hook the motor on/off to the drive's capstan motor to start and stop. If the external plate was large enough and had say a spaced perspex top plate then the tape ends + reflector could be joined and the tape just left to zigzag spool, like a dot matrix ribbon cartridge. There would be no need to do the 8-track pull-the-tape-from-the-centre-style shenanigans.

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