IBMulator is a free/libre, open source emulator for the IBM PS/1 model 2011, able to run with the original ROM. The goal is to create a faithful emulation of the machine, complete of the characteristic 4-quadrant graphical user interface.

In order to use the program you need the original ROM, which is copyrighted by IBM. You won't find it distributed with this package.

IBMulator emulates only the PS/1 with the 80286 CPU (model 2011, sub-models n01, n34, n41.)

See the project page at https://barotto.github.io/IBMulator/ for screenshots, videos and additional information.

IBMulator is distributed under the GNU GPLv3. See COPYING for details.

To obtain the source code go to github.com/barotto/IBMulator

A 64-bit Linux or Windows operating system, a OpenGL 3.3 graphics card, and a 2GHz dual core processor.

Obtain the original ROM. You have the following options:

1. if you have a real PS/1 model 2011, take the program ROMDUMP.EXE in the 'extra' folder and put it in an empty floppy disk; insert the floppy disk in your PS/1 and launch the executable: it will create the ROM image on the floppy disk
2. or open your PS/1 model 2011, extract the EPROMs and read them with an EPROM reader (you also need to merge the 2 halves in 1 file, or 4 in 2 if you have a non-US model)
3. or scour the Internet (there are various ROM sets available.)

Launch IBMulator. A window will inform you that the file ibmulator.ini has been created and where it is placed.

Put the ROM set anywhere you like (inside the same directory of ibmulator.ini is a good place) and update ibmulator.ini with the file name of the ROM you want to use (see below for the correct format.)

You also want to select (or create) the correct keyboard mapping.

From now on IBMulator is ready to run.

For more information regarding the configuration options, see the comments inside ibmulator.ini.

Being a faithful emulator of the PS/1 model 2011, to configure the system (ie. the PS/1, not the emulator) after a configuration change (for instance, if you add or remove a floppy drive), you need a DOS program called CONFIGUR.EXE, otherwise you'll get various POST errors. Likewise, if you want to customize the way the system works, you need to use the program CUSTOMIZ.EXE. Both files are copyright IBM and you have to search the Internet in order to obtain them.

A ROM set can be:

1. a compressed archive in the ZIP format
2. a file with the *.BIN extension, named as you like
3. a directory

A ZIP archive or directory must contain (case insensitive):

• FC0000.BIN : the system BIOS ROM, 256KiB
• F80000.BIN : the regional ROM, 256KiB, optional, only for non-US versions. For international models, this bin file can be merged with FC0000.BIN to form a single 512KiB bin file. In this case FC0000.BIN, if present, is ignored.

Any other file present in the archive or directory is ignored.

If you want to use a single BIN file, this can be 256KiB (US version) or 512KiB (international versions) in size.

The first time you launch IBMulator an empty pre-formatted bootable hard disk image will be created.

If you have an original PS/1 backup disk-set you can restore the machine to its factory state. In order to do so:

1. insert a PC-DOS 4.0 floppy disk in drive A
2. go to the DOS prompt
3. run "a:restore a: c: /s"

Under Linux you can mount the HDD image using this command:
$ mount -o loop,offset=16896 hdd.img /mnt/loop

The offset value is equal to "start sector"*512. The start sector value can be determined with: $ fdisk -l hdd.img

Note: if you change the disk type from the default 35 (WDL-330P) to any other type, the automatically created image will be 0-filled and you'll need to use 'fdisk' and 'format' in order to use it.

IBMulator has 3 different GUI modes.

• Compact: in this mode the VGA image fills the available window space and the control panel, in the shape of the PS/1 system unit, disappears when input is grabbed or CTRL-F1 is pressed. Use this mode if you want an experience similar to DosBox.
• Normal: this is the default mode. The control panel / system unit places itself at the bottom of the VGA display and is always visible.
• Realistic: this is the hardcore mode, for the retro enthusiasts who want to truly experience the PS/1. In this mode the system is rendered in its entirety, monitor included. There are no additional buttons and controls except the originals: volume, brightness, contrast, power, and floppy (you need to use the key bindings for any extra function.) The PS/1 model 2011 is 32 cm (12.6") wide and 34.9 cm (13.74") tall, so you need at least a 24" 16:10 monitor in portrait mode (rotated) to render it at real size.

You can select the GUI mode under the [gui] section of the ini file.

• CTRL+F1: show/hide the main interface (only if GUI is in compact mode)
• CTRL+F3: toggle the machine power button
• CTRL+F4: show/hide the debug windows
• CTRL+F5: take a screenshot
• CTRL+F6: start/stop audio capture
• CTRL+F7: save current state
• CTRL+F8: load last state
• CTRL+F10: mouse grab (only if CTRL+F10 is the mouse grab method)
• CTRL+F11: CPU emulation speed down
• CTRL+F12: CPU emulation speed up
• CTRL+DEL: send CTRL+ALT+DEL to the guest OS
• CTRL+INS: send SysReq to the guest OS
• ALT+ENTER: toggle fullscreen mode
• ALT+PAUSE: pause/resume emulation
• ALT+F4: exit the program

If the grab method is 'MOUSE3', use the central mouse button to lock the mouse.

-c PATH Sets a configuration file to use
-u PATH Sets a user directory from where the program reads the ini file and stores new files, like screenshots and savestates
-v NUM Sets the logging verbosity level (from 0 to 2)

• GCC 4.9
• SDL 2.0.2
• SDL_image 2.0.0
• libRocket (latest version with a patch applied, see notes below)
• GLEW
• libarchive (optional)
• libsamplerate (optional)

If you cloned the code from the GitHub repo you also need the GNU Autotools.

You need libarchive if you want to use zipped ROM sets.

Without libsamplerate audio samples will not be played unless they are at the same rate as the mixer.

$ ./configure --with-librocket-prefix=PATHTOLIBROCKET
$ make
$ make install

Use './configure --help' to read the various compilation options.

If you cloned the code from GitHub, before the 'configure' script you must run:
$ autoreconf --install

Just follow the general instructions. Any missing library will be pointed out; use your distributon's software manager to install them (except libRocket, see notes below).

If you are going to compile using your own version of SDL2, you should compile SDL2 with xinerama and xrandr, otherwise you could experience many problems switching to fullscreen, at least on NVIDIA cards with closed drivers.

If you're using Ubuntu 14.04 you can install GCC 4.9 from the Toolchain PPA.

Currently you have two options:

1. under Linux, cross compile with MinGW
2. under Windows, compile with MinGW + MSYS

Follow the general instructions using this additional 'configure' option: --host=x86_64-w64-mingw32

IBMulator uses libRocket which must be downloaded from http://librocket.com. Unfortunately there is a critical bug that can cause the program to hang while opening the floppy selection window.

I was able to resolve the problem by doing the following:

In "void ElementDocument::_UpdateLayout()" (Core/ElementDocument.cpp:295)

move layout_dirty = false; to the end of the method, so it looks like this:

// Updates the layout if necessary.
void ElementDocument::_UpdateLayout()
{
	lock_layout++;
	
	Vector2f containing_block(0, 0);
	if (GetParentNode() != NULL)
	    containing_block = GetParentNode()->GetBox().GetSize();
	
	LayoutEngine layout_engine;
	layout_engine.FormatElement(this, containing_block);
	
	lock_layout--;
	layout_dirty = false;
}

More info on this issue at libRocket/libRocket#113

I would like to thank the Bochs team. I've taken a huge amount of code from the project. Thank you guys, you made a terrific job! Without your work IBMulator would have taken at least a decade to reach the point where it is now.
Also thanks to the DOSBox team. Only a little bit of code from them but a lot of information and inspiration.