PCem is an IBM PC emulator for Windows and Linux released under a GPL license. Unlike other solutions such as DOSBox or SCUMM, it doesn’t simulate an operating system or game environment. It is a classic emulator designed to emulate 8/16/32 bit x86 hardware used by IBM and other clone manufactures. Therefore it requires originals of both the machine BIOS and compatible operating system to get working.
The aforementioned has both good and bad points. By depending on an authentic BIOS, it allows for a more accurate and nostalgic emulation. However, this means it suffers from all the archaic quirks and configurations that x86 hardware suffered with during the era.
For this reason, I have chosen to emulate a Tandy 1000 personal computer running MS-DOS version 2. It is a well-documented and simple system with a lot of resources online. In this guide, you will learn how to setup the emulation in PCem. And how to convert zipped archived MS-DOS programs hosted online into a floppy disk image for use with the emulation. I will also assume you have some basic knowledge of DOS or Windows Command Prompt.
So we begin by downloading PCem, I will be using PCem v12 for Windows. It is a portable application and is usable from any directory.
The extracted program includes three sub-directories.
srcThe PCem source code which you can delete.
nvrStands for nonvolatile random-access memory and is where PCem keeps the emulated machine save states, such as BIOS changes.
romsROMS are where PCem keeps the read-only BIOS programs. The BIOS is a program that tells the computer how to boot and launches the operating system. As a BIOS is copyrighted software, PCem does not package them.
Also worth looking at is the
readme.txt that lists all the hardware that PCem emulates.
Just like the early x86 era, PCem is far from user-friendly. When you start PCem for the first time, it will exit because it cannot find any ROMs to use.
Emulate the Tandy 1000
The Tandy 1000 was a series of 16-bit x86 MS-DOS consumer PCs created by Tandy Corporation (RadioShack) from 1984 until the end of the decade. You can download the Tandy 1000 ROM
trom102.zip from Tvdog Archives and copy its single ROM file
TANDY1T.ROM into the PCem
rom\tandy\ directory. According to the PCem
readme.txt, you need to rename
Running PCem will now automatically launch the Tandy 1000 emulation. But it may take a while as it’s accurately emulating the rather slow boot of a 4.77 MHz 8088 CPU from 1979. But the emulation still lacks an operating system, so it doesn’t do much except to throw an error prompt.
You can speed things up by opening the Settings menu and choosing
Configure… From there change the CPU: from the authentic 8088/4.77 (4 MHz) to 8088/16 (16 MHz) for nearly four times the performance boost! If only it were that simple back in the day?
Fortunately, the original Tandy 1000 operating system is online for download. Again it is still under copyright and though unlikely a copyright holder may decide to re-enforce that commercial ownership in the future.
In the PCem directory, create a subdirectory to store the Tandy 1000 operating system. I use
d1000.zip to the directory and inside you will find two
.DSK files and a
The images are “raw” copies of the original 360kb floppy disks included with the Tandy 1000 computer. These will work with PCem but they need to use a
.FDI filename extension. So in a command prompt rename the two files with
.DSK extensions to
ren *.DSK *.IMG
Now in PCem open the Disc menu and select Change drive A:..
If your mouse gets captured by PCem, click the middle mouse button or tap Ctrl–End to return it.
Now go to the File menu and select Ctrl+Alt+Del to reboot the emulation with MS DOS. Press Enter to skip the prompts for the current date and time. Now you should be in a MS-DOS prompt at the A drive. You can play around with some DOS commands.
ver MS-DOS Version 2.11
cls clear screen
dir list directory
MS-DOS version 2 is bare-bones, but it now allows us to launch other software for the DOS platform. Open the PCem Disc menu and select Change drive B:…. Select c:\PCemV12Win\floppy\tandy\DESKMATE.IMG. Now at the A> DOS prompt input
dir *.exe will list ten different executable programs. Much like in 1984 we have to take an educated guess and assume DESK.EXE is the correct executable to launch Deskmate.
Deskmate is typical of home productivity software of the era, clunky and somewhat pointless. If you want to embrace 1984, the original Tandy 1000 PDF manual 1kguide.zip has a walkthrough. Chapter 3 onwards covers Deskmate usage, otherwise tapping the F12 key should exit, but it doesn’t seem to work for me. I have to use the File Ctrl+Alt+Del menu option to “soft” boot the emulated computer.
PCem has an open method of dealing with various system configurations. And as such, I try to be as descriptive as possible when naming these saves. First, create a new subdirectory within c:\PCemV12Win called
In PCem open the Settings menu and select Save configuration… Navigate to configs and name the configuration
tandy 1000 deskmate 1.cfg and save.
Now in PCem open Disc and select Eject drive B:. Then open Settings and select Save configuration… This time in configs save the configuration as
tandy 1000 msdos 2.cfg.
You can now switch between both configurations by opening the Settings menu and using the Load configuration… option. Switching configurations will reboot the emulation.
Floppy disk images
Let’s run another piece of software that takes advantage of the Tandy capabilities. Download the Sierra Online 1988 Xmas card. Extract
sierra.zip to a directory. Unfortunately, it comes in a ZIP format, not a floppy disk image format that our Tandy 1000 requires.
- In WinImage open the File menu and select New.
- Select 360 KB standard format and OK as that is what our 1984 era Tandy 1000 uses.
- Open the Image menu and select Inject a folder…
- Browse to the extracted
sierra.zipdirectory and select it.
- It should ask you a confirmation to inject 25 files, click Yes.
- Open the File menu and select Save As…
- Browse to the c:\PCemV12Win\floppy\tandy\ directory.
- Change the Save as type to Image file (*.ima).
- Type in a file name,
sierra xmas.imaand Save.
Sierra On-Line Install
Back in PCem open the Disc menu and select Change drive B:…
Browse for and select
In the DOS prompt run the following.
That will launch the 3D Adventure Game Setup/Installation Program from Sierra On-Line, Inc.
Tap Enter to continue.
On the following Adapter/Monitor selection use the - (minus) key on your numeric keypad to navigate the options and select Tandy 1000 with RGB monitor and press Enter.
On the music/sound selection choose IBM PCjr or Tandy 1000 Internal Speaker and Enter.
Then select the Tandy 1000 Keyboard and Enter. Now you can finally use the arrow keys for the rest of the menu.
Select No and Enter for the IBM compatible joystick.
Select No and Enter for the MicroSoft compatible mouse.
Tap the Esc key when asked to install the game on a hard disk.
Press Enter when Setup is complete.
Now back at the DOS B> prompt type
XMAS and Enter to launch the surprisingly long Sierra Christmas Card from October of 1988. At any time you can tap Alt Q to quit.
Well done you now have a working Tandy 1000 MS-DOS emulation. There are a lot more programs and files to play around with at Tvdog’s Archive.
In a future post, I will run through how to create a companion configuration of a generic IBM PC/XT with both a floppy and hard disk running DOS.