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Thread: Exidy Sorcerer - Vista - Hard sector floppy disk image format question

  1. #1
    Join Date
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    Default Exidy Sorcerer - Vista - Hard sector floppy disk image format question

    I was sent several images of a Sorcerer Vista floppy disks that were imaged by a Kryoflux as raw preservation streams. The streams were
    then run through a version of Samdisk patched by its author Simon Owen. These images are Sorcerer Vista 5.25" SSDD 40T (40T 512x10 s/t).

    The directory of the image is located at 0x2000 = 8192 as shown here:
    Code:
    00002000   00 2D 42 41  43 4B 55 50  33 30 33 33  00 00 00 00  .-BACKUP3033....
    00002010   00 00 00 00  00 00 00 00  00 00 00 00  00 00 00 00  ................
    00002020   00 45 4E 43  4F 44 32 20  20 43 4F 4D  00 00 00 49  .ENCOD2  COM...I
    00002030   04 05 06 07  08 09 0A 0B  0C 0D 00 00  00 00 00 00  ................
    00002040   00 44 45 43  4F 44 32 20  20 43 4F 4D  00 00 00 49  .DECOD2  COM...I
    00002050   0E 0F 10 11  12 13 14 15  16 17 00 00  00 00 00 00  ................
    00002060   00 45 58 41  53 4D 20 20  20 43 4F 4D  00 00 00 60  .EXASM   COM...`
    00002070   1C 1D 1E 1F  20 21 22 23  24 25 26 27  00 00 00 00  .... !"#$%&'....
    00002080   00 4D 45 53  53 32 38 20  20 43 41 44  00 00 00 12  .MESS28  CAD....
    00002090   28 29 2A 00  00 00 00 00  00 00 00 00  00 00 00 00  ()*.............
    000020A0   00 44 49 53  4B 43 41 54  20 44 4F 43  00 00 00 46  .DISKCAT DOC...F
    000020B0   02 03 31 5F  64 B5 B6 B7  B8 00 00 00  00 00 00 00  ..1_d...........
    000020C0   00 44 45 56  43 4E 20 20  20 43 4F 4D  00 00 00 0C  .DEVCN   COM....
    000020D0   32 33 00 00  00 00 00 00  00 00 00 00  00 00 00 00  23..............
    000020E0   00 54 41 50  45 44 49 53  4B 43 4F 4D  00 00 00 0E  .TAPEDISKCOM....
    000020F0   34 35 00 00  00 00 00 00  00 00 00 00  00 00 00 00  45..............
    I can get a good directory by modifying the image to move the directory down to 0x1400 = 5120, the start of Track 1
    as shown below.

    Code:
    00      0 -backup3.033 
    00   9344   encod2.com 04 05 06 07 08 09 0a 0b 0c 0d 
    00   9344   decod2.com 0e 0f 10 11 12 13 14 15 16 17 
    00  12288    exasm.com 1c 1d 1e 1f 20 21 22 23 24 25 26 27 
    00   2304   mess28.cad 28 29 2a 
    00   8960  diskcat.doc 02 03 31 5f 64 b5 b6 b7 b8 
    00   1536    devcn.com 32 33 
    00   1792 tapedisk.com 34 35 
    00    640 disktape.com 36 
    00   2048 diskcopy.com 37 38 
    00  16384    cbas2.com 39 3a 3b 3c 3d 3e 3f 40 41 42 43 44 45 46 47 48 
    00  20224    cbas2.com 49 4a 4b 4c 
    00  16384    crun2.com 4d 4e 4f 50 51 52 53 54 55 56 57 58 59 5a 5b 5c 
    00  18176    crun2.com 5d 5e 
    00   6784    pass2.com 18 19 1a 1b b9 ba bb 
    00    512 diskdriv.com 60 
    00   2560    bascn.com 61 62 63 
    00   1792  rom2dsk.com bc bd 
    00   6912     xref.com 65 66 67 68 69 6a 6b 
    00   8704    vedit.com 2b 2c 2d 2e 2f 30 6c 6d 6e 
    00  11008 gapbios5.asm 78 79 7a 7b 7c 7d 7e 7f 80 81 82 
    00  10496   myword.com 83 84 85 86 87 88 89 8a 8b 8c 8d 
    00  16384  cadas29.asm 8e 8f 90 91 92 93 94 95 96 97 98 99 9a 9b 9c 9d 
    00  29056  cadas29.asm 9e 9f a0 a1 a2 a3 a4 a5 a6 a7 a8 a9 aa 
    00   8704  veditzm.set 6f 70 71 72 73 74 75 76 77 
    00   4352   vedset.com ab ac ad ae af 
    00   1024      cat.com b0 
    00   1024     fmap.com b1 
    00   2304     ucat.com b2 b3 b4
    The files extract sane and the *.COM files execute on my emulator RunCPM.

    What I don't understand is how the first track, or first two tracks can have an extra 0x0C00 = 3072 bytes longer than normal.

    To get cpmtools to work I have to copy Track 1, and then build an image with Track 1 copied intoTrack 0's position, and then
    append the remainder of the image starting with Track 1. Then cpmtools works correctly with the following Definition.
    Code:
    # vista - Sorcerer Vista - SSDD 48 tpi 5.25" - 512 x 10
    diskdef vista
    seclen 512
    tracks 40
    sectrk 10
    secbase 0
    blocksize 1024
    maxdir 64
    skew 0
    offset 5120
    boottrk 0
    os 2.2
    end
    
    # libdsk data below
    [vista]
    description = Sorcerer Vista - SSDD 48 tpi 5.25" - 512 x 10
    cylinders = 40
    heads = 1
    secsize = 512
    sectors = 10
    secbase = 0
    datarate = DD
    So, how does a hard sector format floppy have 8192 hex bytes when there are 10 sectors of 512 per Track?
    8192 divided by 512 gives 16 sectors. 8192 divided by 128 gives 64 sectors. 8192 divided by 256 gives 32 sectors.
    Does the first track contain x number of 128 byte sectors until the data is all written?

    I've got zero experience with Hard Sector Floppy's or Controllers.

    Thanks for any help you can give.

    Larry
    Last edited by ldkraemer; August 10th, 2019 at 04:12 PM.

  2. #2
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    Location
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    Default

    I suspect there are actually 2 boot tracks of 8 sectors of 512 b/s or 16 sectors of 256 b/s or 32 sectors of 128 b/s. All the images have the last Track empty.

  3. #3

    Default

    Are you sure it is 10 sectored? There were 16 sectored 5.25 disk as well.
    Dwight

  4. #4
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    Default

    Dwight,
    No, I'm not sure what the actual floppy has. All I know is the Image was Read with a Kryoflux, and a raw stream was produced. From that
    it was procced by Simon Owen with a patched SAMDISK that he created. And the images were stated to be Sorcerer Vista 5.25" SSDD
    40T (40T 512x10 s/t).


    The problem that cpmtools has is the Directory is at 0x2000 and cpmtools balks at trying to access the image. By copying the HEX Bytes so the
    Directory information is at the start of Track 1, I can access the image with cpmtoos using the offset of 0x1400 = 5120 decimal (512 * 10).

    If the Floppy is 10 Sectors, why is the Directory at 0x2000, when the remainder of the floppy is 512 x 10 sectors per track?
    The directory is 0x0C00 = 3072 bytes past the start of track 1.

    How are the Boot Tracks laid out on Hard Sectored Floppy's? Were the Boot Tracks other than Single Density?

    Thanks.

    Larry

  5. #5
    Join Date
    May 2018
    Location
    Melbourne, Australia
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    Default

    Quote Originally Posted by Dwight Elvey View Post
    Are you sure it is 10 sectored? There were 16 sectored 5.25 disk as well.
    Dwight
    Hi Dwight,

    Yep Vista is a 10 sector system as was Northstar I believe.

    Here is the raw preservation stream as visualised in the HxCFloppyEmulator utility:
    http://www.vcfed.org/forum/showthrea...232#post581232

    Here is a scan of the jacket and label. Definitely 10 sector media.
    http://www.vcfed.org/forum/showthrea...346#post577346

  6. #6

    Default

    As I recall the Victor was 16 sector. It is just that the numbers he was showing looked like 16 sector.
    The N*, HeathKit H8/89 and Polymorphic were also 10 sectored. Each used different sector headers.
    What the Sorcerer used could be anything. The Polymorphic used a double density later but it was still hard sectored. At first it was on 8 inch disk and later they modified the controller to do 5.25. It was interesting that they used a Z80 on the controller card that was more powerful than the main CPU. There was a small dual ported memory window for the sector data. Heathkit used a standard soft sectored controller for their double density. I believe N* used hard sectored for their double density as well but I could be wrong there.
    Dwight

  7. #7

    Default

    Hi guys,

    I'm the author of SAMdisk, and I converted the first head of the KryoFlux images to the raw disk dumps you're looking at.

    I'm certain they're 10-sector disks as each sector has a header with the track number and sector id. The start capture position varies between tracks, but each track includes sector ids 0 to 9 in order (no interleave). The sector data is also followed by a checksum byte, which is correct for all the sectors in the images I've examined. In the sample vista_mitsu_033 image you're looking at, all 40 tracks on head 0 have the same regular 10-sector format, with no room for anything else. The raw images are written out in sector order (0 to 9) on each track, and should contain all the available sector data.

    If there's anything specific you want me to look into in more detail, please let me know. Is it possible that head 1 contains some of the missing data? We're still missing the first 4 tracks on head 1 due to the head offset of reading flippy disks in a double-sided drive.

    Simon

  8. #8
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    Default

    Simon,
    First of all, THANKS for SAMdisk! I haven't used it in a while, and likely need to check the latest version
    compared to what I'm using.

    It doesn't really matter to me that the directory is located at some OFFSET to where I'm thinking it really
    should be. I was just trying to figure out how the Hard Sectored Floppy Controller was laying down the
    boot track(s) on the floppy with 512 x 10 Sectors Per Track.

    The files have been retreived and all appear to be valid. The *.DOC files are SANE, as well
    as the *.ASM files I viewed. (I don't really need the valid boot tracks, as long as I can get the directory location
    sorted, as I was just after the data files on the Floppy Images. Along with fine tuning the cpmtools (& libdsk) definition.)

    My old Radio Shack TRS-80 Model 1 has three MPI Flippy drives, that were modified by Aerocomp. They are B-51 type
    Floppy Drives. There are two Optics for the Index Signal, and the orientation of the Floppy determines which one is active.
    There are also two optics for the Write Protect. Perhaps this Optic arrangement would help you retreive the information
    on the back side of the Flippy.

    Thanks.

    Larry

    IMG_1.jpg.........IMG_2.jpg
    Last edited by ldkraemer; August 15th, 2019 at 01:45 AM. Reason: typo

  9. #9
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    Default

    Quote Originally Posted by Dwight Elvey View Post
    What the Sorcerer used could be anything.
    Does this image convince you?


  10. #10

    Default

    You know I designed a hand held punch to make 10 sectored disk from your pile of 360k disk. It was made such that you don't have to remove the bisket from the envelope. There is a group that made a newer version. Check with sebhc to see if any are available from there last run.
    Dwight

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