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TRS-80 Emulation: Disk Conversion Instructions

by @ 7:01 pm on February 20, 2009.
[Model I]      [Model III] TRS-80 Diskette to DMK Conversion     [Model 4]      [Model 4P]


Converting TRS-80 Disks for use in an Emulator
The Problem:
Modern hardware and operating systems are making it more difficult to convert actual TRS-80 disks into an emulator (DMK or DSK) format.

Some of the obstacles are:

   
  • No ability to read single density disks whatsoever
       
  • Current operating systems do not allow for direct hardware addressing
       
  • No 5.25″ drive support in the BIOS
    Pure Double Density TRS-80 Disks (Model III, 4 and 4P)
    While you can you can always send the diskettes to me to convert, if you wish to try to convert Model III, 4 or 4P disks yourself, you will need:
       
  • A 5.25″ disk drive (obviously); and either
       
  • A very very very old PC (i.e., IBM PC/AT, PC/XT, or the like) to get BIOS Support
  • A Catweasel Controller Card
       
  • The appropriate software (below on this page)
    Single-Density or Mixed Density (Model I) other than TRSDOS and NEWDOS/80
    Reading single-density disks (which is what the Model I used; noting that even double density disks tended to have a single density track 0) is MUCH more complicated. “Modern” computers do not have the crystal needed to generate a single density clock, so they simply cannot read single density. Even those that can will have trouble with TRSDOS 2.x (DAM problem) or NEWDOS/80 v1.x (DAM problem) or NEWDOS/80 v2.0 (Inner Track Problem).
    To convert Model I disks (other than TRSDOS or NEWDOS/80) to emulator format you can send the diskettes to me or you will need:
       
  • A 5.25″ disk drive (obviously); and either
          
  • A PC with an ISA port and any of the following
    The Adaptec 1522 SCSI controller (ISA, non-bus-mastering, NS8473 Controller) can read/write/format FM (Single Density) floppies, including LDOS-format SD floppies. TRSDOS2.3 directory tracks CANNOT be handled on these because of the DAM.
    It is possible that the Adaptec 1542 SCSI controller (ISA, bus-mastering, NS8473 Controller)
    The Acculogic ISApport SCSI adapters (SMC FDC37C65) will read 360K Double Density but will not read single density on a 1.2MB HD drive.
          
  • A Catweasel Controller Card
    Single-Density (Model I) TRSDOS and NEWDOS/80
    To convert TRSDOS or NEWDOS/80 disks to emulator format you can send the diskettes to me or you will need:
       
  • A 5.25″ disk drive (obviously); and either
          
  • A working TRS-80 Model I (where you would then copy the files to a more friendly OS like LDOS)
          
  • A working TRS-80 Model III or 4 (where you would then copy the files to a double density operating system)
          
  • A Catweasel Controller Card

    WARNING!!!!
    Before putting a disk in your drive, make sure to inspect it. Improperly stored disks will degrade, and will shred in your drive. Inserting one of these disks in your drive will not only produce a disheartening noise, but will likely coat your read/write head with oxide, requiring you to clean the heads. Here are some pictures I took of some of these improperly stored or otherwise decayed disks. Click on the images for more detail:
         

    Reading/Writing TRS-80 Disk Media on a PC
    If you have a 5.25″ drive hooked up to your IBM PC, the following programs can be used to read TRS-80 disks into the DMK/DSK format. If you want to read Model 1/3/4 disks and have a Catweasel card, use Tim Mann’s CW2DMK utility. If you want to read Model 1/3/4 disks and do not have a Catweasel card, use Matt Read’s READDISK utility. If you want to read COCO disks, use Jeff Vavasour’s RETRIEVE utility.

    Platform         Utility Name     Version   Date         Author       Home Site
    DOS Catweasel Utilities v4.4 January 15, 2010 Tim Mann Home Site
    Utilizes special hardware called a Catweasel card to read all formats of TRS-80 disks on a PC. Also includes a utility of general use for converting DMK format disks to DSK format.
    Platform         Utility Name     Version   Date         Author       Home Site
    DOS Catweasel Utilities v4.5 (UNOFFICIAL) May 19, 2014 George Phillips based on Tim Mann’s v4.4  
    Unofficial build with takes Tim Mann’s v4.4 and adds additional features: [1] Ability to cache good sectors and output the best possible read, [2] Ability to continue retrying once the retry count has expired, [3] Senses MS-DOS Format on Side 2 and ignores it, [4] Ability to drump raw track data into files.
    Platform         Utility Name     Version   Date         Author       Home Site
    DOS READDISK

    v2.10 July 3, 2007 Matthew Reed Home Site
    Documentation
    READDISK transfers files from a TRS-80 Diskette to an IBM .DSK file without special equipment. This version can also read Tandy 1000 disks.

    Please note that not all PC disk controllers are capable of reading TRS-80 disks. This is a limitation of the disk controller, not READDISK. If you have trouble, try running READDISK on other PC’s until you find one that can read your disks. Remember, you only need to read your TRS-80 disks once to convert them to disk images, so be sure to use the “Retry” command heavily.
    Please note that not all PC disk controllers are capable of reading TRS-80 disks. This is a limitation of the disk controller, not READDISK. If you have trouble, try running READDISK on other PC’s until you find one that can read your disks. Remember, you only need to read your TRS-80 disks once to convert them to disk images, so be sure to use the “Retry” command heavily.
    The following programs are over a decade old and regardless of whether or not they even work, the above are much better choices at this point in time.
    Platform         Utility Name     Version   Date         Author       Home Site
    DOS Retrieve

    v1.3 December 10, 2000 Jeff Vavasour Home Site
    To transfer files from a COCO Diskette to a .DSK image.
    Platform   Description   Version   Date   Author   Home Site
    TRS-80 Transfer   January 5, 1999 Timothy Purves  
    Transfer runs on a TRS-80 and will read/write to IBM PC Formatted 5.25″ disks.
    Platform         Utility Name     Version   Date         Author       Home Site
    DOS GETDISK and
    PUTDISK
    N/A June 28, 1994 Jeff Vavasour Home Site
    The TRS-80 Model 4 Emulator’s virtual disk utilities have been provided free for download in order to allow you to determine whether your PC has the features necessary to read and write TRS-80 floppies directly. The emulator can either access your TRS-80 floppies directly in its floppy drive, or as images copied to your hard drive. Either way, you need to be able to determine whether the PC hardware can read the floppies.
    Platform         Utility Name     Version   Date         Author       Home Site
    DOS PC Cross Zap v1.5 July 7, 1990 Michael J. Gingell – Hypersoft N/A
    Reading, writing, editing and formatting TRS-80 disks on a PC.
    Platform         Utility Name     Version   Date         Author       Home Site
    DOS TRS Cross v2.01 March 20, 1990 Powersoft N/A
    Platform         Utility Name     Version   Date         Author       Home Site
    TRS-80 Hypercross v3.0a December 31, 1987 Michael J. Gingell – Hypersoft N/A
    Reading, writing and formatting PC and CP/M disks on TRS80 models I, III and IV.

    Are there any guidelines for scanning?
    This is actually here because many kind people have asked if I wanted them to scan certain items in their collection. To avoid the various searching for prior sent emails, the following is a list of pointers and requests when scanning for the site:

    Scanning Modes:

    • Color pages should be scanned in True Color

    • Non-Color pages should be scanned in full grayscale … NEVER in “BITMAP” or “Black and White”

    • Images should be scanned in at LEAST 400 DPI

    • Images should be saved as non-compressed TIFF’s. NEVER as JPEG’s.

    Processing:

    • Make sure the text is more or less straight … if its at a sharp angle, please re-scan the page.

    • Make sure each page size is the same dimension. Note: Rotating a scan in an image editor, rather than doing the re-scan, will change the scanned page dimensions.

    • Trim off any unintended dots at the margins. Jagged edges, overscans, etc., all take up space in addition to being useless. If clear those stray items, the pages will look nicer AND will take less space.

    Note: If you cannot do the “Processing” part, then I will do it for you, but will need the TIFF’s. I can set up a temporary FTP site for you to upload to if you contact me.

    2 Responses to “TRS-80 Emulation: Disk Conversion Instructions”

    1. Ian says:

      I recently used spark plug cleaner to clean disks in bad condition and was able to read data from them after a little spray straight on to the platter ! as a last resort I was amazed it worked :)

    2. Craig Bok says:

      I have a couple of 5 1/4 floppy disks that have our Christmas letters from 1982 & 1983 on them. I would like to get this data recovered. Any idea where I can go to get this done?

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