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Thread: Need boot floppy for Xerox 820-II

  1. #1

    Default Need boot floppy for Xerox 820-II

    I've got the hardware cleaned up and am looking for a boot floppy for the 820-II.
    I'm in East Texas.

  2. #2
    Join Date
    Sep 2006
    Location
    Silicon Valley
    Posts
    2,199

    Default

    8" or 5" ?

  3. #3

    Default 8", Shugart SA80x Single-sided drives. Not sure of the density this system used.

    Quote Originally Posted by Al Kossow View Post
    8" or 5" ?
    8", Shugart SA80x Single-sided drives. Not sure of the density this system used.

  4. #4
    Join Date
    Mar 2013
    Location
    Chaffee, MO
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    Default

    It's likely SD with 26 Sectors, 128 Bytes per Sector, 77 Tracks, Single Sided, FM
    (((26 * 128) * 1) * 77) = 256256 Bytes

    Code:
     
     0/0 500 kbps SD  26x128
         1  2  3  4  5  6  7  8  9  10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 
         D  D  D  D  D  D  D  D  D  D  D  D  D  D  D  D  D  D  D  D  D  D  D  D  D  D  
     1/0 D  D  D  D  D  D  D  D  D  D  D  D  D  D  D  D  D  D  D  D  D  D  D  D  D  D  
     2/0 D  DE5DE5D  DE5D  D  DE5DE5D  DE5D  D  DE5DE5D  DE5D  D  D  DE5D  DE5D  D  D  
     3/0 D  D00D00D  D  D  D  D  D00D  D  D  D  D  D00D  D  D  D  D00D00D  D  D  D  D00
    cpmtools and libdsk definitions:
    Code:
    BEGIN A1  Generic CP/M - SSSD 8" - 128 x 26
    INSERT 22DISK Definition here
    END
    
    # A1  Generic CP/M - SSSD 8" - 128 x 26
    diskdef a1
      seclen 128
      tracks 77
      sectrk 26
      blocksize 1024
      maxdir 64
      skew 6
      boottrk 2
      os 2.2
    end
    
    # libdsk data below
    [a1]
    description = A1  Generic CP/M - SSSD 8" - 128 x 26
    cylinders = 77
    heads = 1
    secsize = 128
    sectors = 26
    secbase = 1
    datarate = HD
    Directory Listings look sane, but files don't seem to extract sane using cpmtools.

    Code:
    $cpmls -f xer5 -D X820IICP.RAW
         Name    Bytes   Recs  Attr     update             create
    ------------ ------ ------ ---- -----------------  -----------------
    CONFIGUR.COM    12K     92 R  
    COPY    .COM     5K     38    
    DDT     .COM     5K     38 R  
    DUMP    .COM     1K      4 R  
    ED      .COM     7K     52 R  
    HELP    .TXT    30K    235 R  
    INIT    .COM     4K     28 R  
    LOAD    .COM     2K     14 R  
    MOVCPM  .COM    10K     76 R  
    PIP     .COM     8K     58 R  
    STAT    .COM     6K     41 R  
    SUBMIT  .COM     2K     10 R  
    SW      .COM    12K     92    
    SWAP    .COM     1K      3 R  
    SYSGEN  .COM     2K     11 R  
    XSUB    .COM     1K      6 R  
       16 Files occupying    108K,     134K Free.

    Larry
    Last edited by ldkraemer; February 4th, 2020 at 04:16 AM. Reason: typo

  5. #5

    Default

    It's some months ago larry helped me with xerox820 22disk parameters -> Xerox 16/8 - SSDD 8" - 256 x 26

    Here in germany A friend of mine has a xerox 820 and needs a bootdisk.

    At http://www.bitsavers.org/bits/Xerox/820-II/ there are a lot of images and I inspected all for their content.


    https://forum.classic-computing.de/f...055#post154055

    https://forum.classic-computing.de/f...257#post160257
    here is a link to a pdf I made about:

    https://forum.classic-computing.de/i...ii-images-pdf/

    And for the images from http://www.bitsavers.org/bits/Xerox/...0ii_images.tgz I made an index as possible as
    I could https://forum.classic-computing.de/i...oxes-dirs-zip/

    So I hope you find what you need.

  6. #6
    Join Date
    Mar 2013
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    Chaffee, MO
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    Default

    Fritz,
    Yes, the B12D2.IMD, B12D3.IMD, and B12D4.IMD are SS/SD, FM with 26 Sectors, 128 Bytes per Sectors,
    and 77 Tracks. I've got sane directory listings, and extracted several .ASM and .SUB files to make sure they
    are also sane.

    Then, I used the HxC Software to create B12D2_IMD.SCP, B12D3_IMD.SCP, and B12D4_IMD.SCP, that
    should be able to be written to floppy's with the GreaseWeazle, to boot with.

    Larry
    Last edited by ldkraemer; February 4th, 2020 at 07:13 AM. Reason: typo

  7. #7

    Default

    Quote Originally Posted by ldkraemer View Post
    Fritz,
    Yes, the B12D2.IMD, B12D3.IMD, and B12D4.IMD are SS/SD, FM with 26 Sectors, 128 Bytes per Sectors,
    and 77 Tracks. I've got sane directory listings, and extracted several .ASM and .SUB files to make sure they
    are also sane.

    Then, I used the HxC Software to create B12D2_IMD.SCP, B12D3_IMD.SCP, and B12D4_IMD.SCP, that
    should be able to be written to floppy's with the GreaseWeazle, to boot with.

    Larry
    Hi Larry,
    I'm am allways interested on other ways without the catweasle controller and IMD.

    Does the greaseweasle truely write to 8" floppydisks?

    As a modern linux driven PC has only a 1.44MB diskdrive possible how can I write to real floppydisks?

  8. #8
    Join Date
    Mar 2013
    Location
    Chaffee, MO
    Posts
    1,393

    Default

    Fritz,
    The GreaseWeazle is a stand alone STM32F103C8T6 that uses an adapter Board (either
    a PC type with 34 Pins, or a Amstrad type with 26 Pins for 3" Floppy) to interface with the Floppy Drive.
    A Python3 Program is used on Windows, MAC, or Linux to communicate to the GreaseWeazle.
    While I haven't used it on an 8" Floppy it's supposed to work the same way on an 8" Floppy as
    it does on a 3.5" or 5.25" Floppy. The GreaseWeazle writes back the actual flux transitions.

    To read a 77-cylinder single-sided disk:
    $python3 gw.py read --scyl=0 --ecyl=76 --single-sided mydisk.scp /dev/ttyACM0


    Writing a Disk:
    $cd Downloads/Greaseweazle-v0.7/
    $python3 gw.py write mydisk.scp /dev/ttyACM0

    Check it out.

    Larry
    Last edited by ldkraemer; February 5th, 2020 at 04:53 AM. Reason: added commands

  9. #9

    Default

    Hi,
    I have this system, I'll try to dig it out and see if my disk still works and try to make copies.

  10. #10
    Join Date
    Mar 2013
    Location
    Chaffee, MO
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    Default

    Fritz,
    I've found that the Samsung SFD-321B modification information at
    https://majzel.blogspot.com//conver...8-to-35-inch-
    has some mis-leading information. To get the SFD-321B into Mode 3 for 1.6M and 360 RPM, the Jumper needs
    to be across OPA and Pin 2 needs to be isolated from the Interface and tied to GND. This PULLS Pin 2 "LOW"
    for selecting 360 RPM in the Drive Logic. I've tested the Write and Reading a file, to load into HxC Software.
    It's now displayed at 360 RPM as these Photos show the actual differences. All I need now is a FD50to34 Adapter,
    FDAP, or Mark Blair's (NF6X) Adapter from Github. THANKS to Keir for all his Hard Work on getting the GW Software
    functional for SS/SD, 26 Sector x 128 Byte, 500 kbps, 8" duplication.

    Larry

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