Tool-assisted game movies
When human skills are just not enough

Emulator Resources / P Cem / DOS

<< Emulator Resources / P Cem
<< Emulator Resources

The entirety of the general guide applies here, this page will give you specific instructions and tips for using DOS in PCem.

If you need a boot disk, you can use this boot floppy disk or boot directly from a FreeDOS installation CD.

Table of contents [expand all] [collapse all]

Premade configurations

To make setup as easy as possible, you can pick one of these configurations and follow the steps to make an era-appropriate DOS computer.

These configs were all made with the TASVideos PCem v17 branch, commit 55f0fdb.

Late 80s


You will need the following ROM files: (THESE ARE CASE-SENSITIVE!)

   Filename                      MD5
   109592-005.u11.bin            70e208d5992be21b26fe796d76964c1d
   109591-005.u13.bin            d35bab5b74fc21fef900b14b0807e126
Put them in the folder ~/.pcem/roms/deskpro386/.

Early 90s


You will need the following ROM files: (THESE ARE CASE-SENSITIVE!)

  Filename                      MD5
  1007by0r.bi1                  26d8f651e468874e852bdd1ffb6e6804
  1007by0r.bio                  15d245587d08979f16383190c55fb153
  gd5430.bin                    d4ba691ce5e04d950ca7624050e6b409
Put them in the folder ~/.pcem/roms/pb570/. If there is a file called flash.bin in this folder, delete it.


Make a new config with the following specs. If something is not specified, leave it at default. You may not get some of the options when you make a new config; if this happens, click "OK" to save it and then try editing it again.


  • Machine: [Socket 5] Packard Bell PB570
  • CPU: Intel Pentium 133
  • Memory: 8 MB
  • Synchronize time to host clock: Checked


  • Device: Built-in video (2 MB memory)
  • Speed: Default
  • Voodoo graphics: Unchecked


  • Device: Sound Blaster 16 (Address 0x220, DBOPL)
  • All options unchecked
  • LPT Device: None


  • HDD: [IDE] Standard IDE
  • FDD1: 3.5" 2.88M
  • FDD2: 5.25" 1.2M
  • CD Model: PCemCD
  • CD Speed: 24x
  • Drive 0 Primary Master (C:): Hard drive, make a new hard drive of type 46 (Sectors 17, Heads 15, Cylinders 1224, 152 MB)


  • Mouse: 2-button mouse (PS/2)


The default NVR file used is pb570.nvr (md5: 9228bf13f3fe46351b1885e073558b67). It can be found in the folder you installed PCem in under /nvr/default/pb570.nvr. To be completely sure your NVR file starts off clean, take this file, copy it to ~/.pcem/nvr/ and name it after your config file (e.g. if your config is named early90s, name it early90s.pb570.nvr.) If there is already a file named this, delete it and replace it.

At this point you can run this verification movie in libTAS to get our exact files: http://tasvideos.org/userfiles/info/69366517034064699


Launch the config and wait a while - the system needs to reconfigure itself. Eventually, you will see this screen:

This is normal, it's just a warning that something changed in the system. Press F1 to load setup. Press F5 to load the setup defaults and press enter - this ensures the NVR starts from a clean slate.

Back on the setup screen, select Floppy Options and press enter.

On the Floppy Options screen, set the drives to what they were in the config: A: is a 3.5" 2.88 MB and B: is 5.25" 1.2 MB.

Press Esc to back out to the main setup screen. Now select Boot Options and press enter.

Set the boot order so that the First Boot Device is CD-ROM. Disable the rest for now. Remember how to do this - you will need to change this again later! Press F10 to save and exit.

The PC will restart looking for bootable media: proceed to the FreeDOS Installation section.

Late 90s


You will need the following ROM files: (THESE ARE CASE-SENSITIVE!)

  Filename                      MD5
  6BX.F2a                       8ea65e0c1c4934e9a0105bb3fe33a9e9
Put this in the folder ~/.pcem/roms/ga686bx/. If there is a file called flash.bin in this folder, then delete it.

The GPU also needs a ROM file:

  Filename                      MD5
  86c764x1.bin                  fbc57ef320053c50d9034ef493abda4d
Put this in the folder ~/.pcem/roms/.

FreeDOS installation


These configs will have FreeDOS 1.2 installed on them. For these configs, you will need the Legacy installer. You can get everything on the FreeDOS website.

Right-click on the PCem window and use CD-ROM -> Load image to load FD12LGCY.iso (md5: a55750577b4c3b88dba489df4f929f88). If your system is older and doesn't support booting from CD, you'll also need to download FD12FLOPPY.zip (md5: 6c3077be89db961a883b1587385aa65e) and mount FLOPPY.img using Disc -> Change drive A. Restart the system when everything is mounted.


You will get some messages about illegal partitions - this is normal, the drive hasn't been formatted yet. Partitioning and formatting is built in to the FreeDOS installer to make this as easy as possible. On the first couple screens, choose English and choose Yes to continue with the installation. You will get a message saying drive C: is not partitioned yet, choose Yes to continue. Once the partitioning is complete, reboot the system with System -> Hard Reset (PCem doesn't like the installer's restarts for some reason).

Once the CD boots up again (you may have to mount it again), pick English again and Yes to continue the installation. The installer will ask you if you want to format, choose Yes. The drive will be formatted and you should see a screen like this:

Once it finishes loading, pick US English as the keyboard layout. When it asks what FreeDOS packages to install, pick Base packages only.

Choose Yes on the next screen to install. Installation will take a few minutes. When it's done, reboot with System -> Hard reset again.

Boot order

The hard drive is now bootable, so you should change the boot order so that it's the first option. When the system restarts, enter the BIOS again. How you do this will depend on the chipset you're using.

Early 90s

Hit F1 at POST and go to Boot Options. Put the list in the following order: Hard Disk, CD-ROM, Floppy, Disabled. Press F10 to save and exit.

Set blaster

The last thing to do is set the proper Sound Blaster variables. To do this, you will have to edit AUTOEXEC.BAT.

When you boot the config, it will now take you to a C:> prompt. Type edit AUTOEXEC.BAT into the prompt and hit enter. You should see this:

Note the line that starts with SET BLASTER - this is the one you will be changing. What you change it to depends on the type of Sound Blaster you picked - look here for more info. The IRQ is always 7, the DMA is always 1, the high DMA is always 5, and the I/O port was set in the Sound tab when the config was made. For the premade configs, replace this line with one of the following:

Early 90s and Late 90s

  SET BLASTER=A220 I7 D1 H5 P330 T6
Once this line is changed, in the editor pick File -> Save and then File -> Exit. The config should now be ready to use!

Note that you will not have the same file hashes as the ones we provide unless you run the verification movie. The times and dates stored in the files will be different.

Custom installation

If you'd like to format the hard drive yourself and install something else, put in your boot disk and restart PCem.

After you boot PCem with the boot disk in the floppy drive, eventually you'll be met with an A:> prompt.

Any good boot disk will have FDISK and FORMAT on it.


  • Type fdisk into the prompt and hit Enter.
  • Say yes to large disk support.
  • Choose option 1 on the next menu to create a DOS partition
  • Pick option 1 again to make a primary DOS partition.
  • Say yes to using the maximum available space and making it the active partition.

If all goes well, you should see a screen like this:

The drive is now partitioned. Escape out of FDISK and restart PCem like it wants you to.


Now it's time to format.

  • Let the system boot up again and get to the A:> prompt.
  • Type
    format c:
    and press Enter.
  • You'll get a warning that all data will be lost, but there is no data anyway, so say yes.
  • Give the volume a name (or leave it blank) and hit Enter.

You should see a screen like this once it's finished:

The hard drive is now ready to be used. After you install your game and get libTAS set up, you should be ready to start TASing at this point.


You can press F8 after the POST screen to step through each line in fdconfig.sys and autoexec.bat. Only do this if you know what you're doing, but you can use this to skip loading things like emm386, ctmouse, and/or the CD drivers.

Combined RSS Feed
EmulatorResources/PCem/DOS last edited by slamo on 2021-02-09 22:11:09
Page info and history | Latest diff | List referrers | View Source