copy protected floppy disk images in PCEM

what would be the best format to use in PCEM for copy protected floppy disks and what would the commands to convert from SCP to this format ?


  • PCEM doesn't support non-standard disk.

    PCE supports non-standard disk (including copy protected disk) well.
    86Box supports copy protect disk but it doesn't work well than PCE.
  • 86box has it's own image format for copy protected disks - 86f.

    Unlike PCE it does not support some types of copy protections, i.e. based on weak bits or physically damaged disk areas. New 86f format revision was promised by developers long ago, but nothing has changed in the last couple of years. So it's still "to be released at some point in the future".

    86f is a track-level based engine (PCE works on sector level), therefore 86f can do some tricks PCE cannot. For example try to create a floppy installation of MS Word for DOS 1.00 on both emulators and see the difference (PCE will fail to do it).

    Also, if some protected program requires 286+ CPU, you cannot run it on PCE anyway, so 86box is the only option here. But since 86box's 286+ CPU code doesn't support some features like pre-fetch queue emulation, protections based on such tricks will refuse to work correctly.

    Long story short: both emulators have it's advantages and disadvantages.
  • edited May 2022
    I have games and applications for DOS or PCbooter with over 1000+ disk copy protection.
    Most of them are for 8086/8088 CPU.

    There are only a handful of games that require more than 286 CPUs.

    I'm not playing with puns, I'm showing them in action, like attaching screenshots.

    I tested over 1000+ copy protected game/program on PCE.

    Most of them runs on 8086/8088.
    (There is few game/utility run on 80286+ with copy protected disk.)

    Finally, it is said that it does not run on 286 or higher, but to be sure, games and utilities with disk copy protection that run on 80286 or higher are only at a partial level when looking at the total number of titles. (If you look at the numbers I have, if you look at the number based on 1000, it will be 5.)
    (Example: Lotus 1-2-3 R3.0, Lethal Weapon, Cool World, Hook, Jurassic Park)

    P.S. I tested original Gunship v429.01

    PCE runs well with installation.
    86Box runs, but writing is not allowed to access the disk.

    1) PCE

    2) 86Box

  • thanks for the tip, I will try PCE.
    Can PCE handle SCP format ? if not which one tu use and how to convert from SCP ?
  • @callmejack

    SCP format can't be handle directly on PCE.

    But you can convert SCP --> PRI (by PFI.EXE) --> PSI (by PRI.EXE)

  • @ibmpc5150
    86Box runs, but writing is not allowed to access the disk.

    First you need to create a 86f image from the original KF/SCP using HxC tool (via modified MFM).

    The PCE emulator has floppy conversion tools in \bin folder - pfi.exe (for FLUX formats), pri.exe (for RAW formats), psi.exe (for sector-based formats) and pti.exe (for tape formats).

    So conversion from SCP to PSI in the simplest situation will look like that:
    pfi disk.scp disk.pfi
    pfi disk.pfi -p decode disk.pri
    pri disk.pri -p decode mfm disk.psi

    In some more complex cases you'll need to specify parameters like bitrate or define a revolution required to be decoded, i.e.:
    pfi disk.pfi -R 1 -r 500000 -p decode pri disk.pri

    There could be even more nuances, it all depends on an application and it's individual for each case.
  • edited May 2022
    Conversely, the disadvantage of 86BOX is that it cannot run with sector level emulation like PCE unless it is converted to 86F.

    I only give information to PCE to run my dumped disk copy protected game+ program including unknown titles.
    Because there are various tips on how to use PCE that are not disclosed in the manual, it is not easy to follow this part in other emulators. I never share such private or advanced tips without the consent of the authors of the PCE.
  • 86box can work with sector-based formats that support copy protections, i.e. td0 (Teledisk), but it mounts those as read-only. It's not a problem unless a program wants to write something back to the floppy.
  • edited May 2022
    PCE is also possible to emulator track level.
    PRI format exists just like 86F.
    I think PCE author seems not to think about emulation of track level.
    (I think it seems to enough with sector level. Mosf of games dumped from original disk works well.)

    It is not easy to follow this part on other emulators because there are various tips that are not disclosed in the manual for the usage of PCE not only on the emulator but also on the conversion of disk sector images. I never share such private or advanced tips without the consent of the authors of the PCE.
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