User FAQ



License information

License of Xcom graphics user interface, and all of its built-in tools:

1. The Xcom graphics user interface and its tools are provided ``as is'' and without
any express or implied warranties, including, without limitation, the implied warranties
of merchantability and fitness for a practicular use.
The creator of Xcom is rejecting any direct or indirect responsibility for the
damages caused by the Xcom graphics user interface or its tools. Use at your own risk!

2. It is not allowed to modify or disassemble Xcom. It is not allowed to extract separate
parts and tools from Xcom.

3. The fact of the intended use of Xcom and its tools not alters the copyright of the works and
documents used or created with the help of Xcom and its tools.

4. The creator of Xcom takes no responsibility for the actions of the users.

FAQ: Frequently asked questions (DOS version)

Xcom is currently released only for DOS.
You will see a few bugs for sure. You may notice problems, so here is a table with the frequently asked questions:

Q: What compiler is used to build Xcom? (Dos)
A: Xcom was built using DJGPP (g++), and it requires cwsdpmi or HDPMI (recommended) to enter 32 bit.
Please read the official source of DJGPP and CWSDPMI or HDPMI for informations if you need help regarding to those.
Its recommended to run HDPMI32i.exe before executing Xcom!

Q: Some special hotkeys doesn't work, or causing system hang.
A: Those keys can not be enumerated by DJGPP's dos keyboard driver. I can't fix this.
Alternative keys (such as control+ESC, shift+ESC, F1/2/3/4/5/6 keys are available to perform certain funcionality).

Q: Cursor keys don't work on i7-class computers.
A: BIOS emulation is buggy on some modern hardware, and cursor key emulation triggers the virtual mouse instead. I can't fix this problem.

Q: Will Xcom work on 64 bit computers?
A: Yes, but some modern 64 bit PC computers will be slower than expected when running a DOS environment.

Q: Opening a directory from a hard disk and floppy drive takes very long time, it loads the entire directory instead of loading it in small chunks.
A: This is the behavior of the disk driver in your DOS (clone) and the bug is not in my code.

Q: Opening large directory from CD, DVD and Blu Ray drives taking very long time, and causes multiple second stutters, if the directory has multiple 1000s of files.
A: Due to a bug in DJGPP or the disc driver itself, acquiring the directory entries taking too much time. I did several workarounds to make it less of a pain. Old CD and DVD burners are very slow under DOS, and loading the directory entries will not be a pleasant experience. Old Blu Ray burners are even slower, and its not recommended to use Blu Ray burner, if you want to browse directories with more than a few 100 files. Late CD-ROM and DVD-ROM readers are much faster, and they will be able to load the directory list faster.

Q: Will Xcom run on computers where memory managers and high memory area is unavailable?
A: Yes, Xcom usually runs on every computer if you can boot DOS.

Q: How to enable mouse wheel?
A: Standard dos mouse drivers doesn't support a wheel. I can't fix this issue.
There are reports of a Cutemouse wheel API, which i might research later.

Q: File send and receive doesn't works.
A: DJGPP doesn't supports networking under DOS. I can't fix this issue.
(No, the Wat32 the network API for DOS and DJGPP doesnt compiles since decades.)

Q: What DOS brands are supported by Xcom?
A: All of them should be supported if they are supported by DJGPP, including homebrew DOS variants.

Q: File selector behaves strangely, can minimized, maximalized, doesn't follows the parent.
A: I know about this bug, and i will fix it later.Fixed in current version.

Q: Password-based login screen doesn't locks the programs properly, it just floats there.
A: Log-in system is not yet fully implemented. Will be fixed in the beta.Fixed in current version.

Q: The chess AI is very broken, and it makes a lot of fails.
A: I don't know why and how the chess AI broke, but i will try to fix it in the beta.

Q: The software doesn't works on my 8086/286 computer.
A: This software only works on 32 bit and 64 bit processors.

Q: The software is strange when used on some 386 systems.
A: I don't have any 386 processors, so i can't test it.

Q: The software is having issues when no FPU is present.
A: I don't have any processors without an FPU so i cant test it, i compiled the code with FPU emulation anyway.

Q: I can't use 640x480 but i have a VGA card. What is the problem?
A: The program requires SVGA video card with VESA VBE to display 640x480 or bigger resolutions, even if standard VGA also supports 640x480. Try 640x350 1 bit (EGA) resolution, or 320x200x8 VGA instead.

Q: I have an SVGA video card, but no 640x480 or resolutions above it is available.
A: For some old ISA based video cards, you should install VESA VBE drivers, such as UNIVBE, univesa, or the official VESA drivers from your manufacturer.
Please note, graphics cards usually come with an integrated driver firmware (VBE)
Xcom contains no hardware-level graphics drivers, and it will use this VBE instead.
If you have issues, you can always use official or third party DOS VBE drivers.

Q: I have no sound.
A: You must install your sound card drivers. Sound Blaster emulation is needed to have sound.

Q: I still have no sound.
A: Ensure your port is 220 or 240, your DMA channel is 1.
The SET BLASTER environment variable must be present if your DMA is not 1.

Q: The sound seems to be mono, and limited to be 22 khz regardless of the settings.
A: Xcom is limited to 22050Hz, mono sound, with 8 bit samples. This is for various compatibility reasons. Standard SB clones support up to 11025 Hz, or sometimes, 16000. If you having issues, its recommended to set the software to output 11025 Hz sound.

Q: The mouse doesn't works.
A: You must load a mouse driver for DOS, such as cutemouse. Some modern computers (with USB) will have no PS2 emulation for USB mouses, and the USB mouse will not work on those. A serial mouse is recommended.
Press num-lock to access keymouse on the numpad.

Q: Can i print from Xcom?
A: Xcom doesn't supports printing, your DOS printer drivers and tools will may or may not work regardless.

Q: Does Xcom supports multiple processor cores on DOS?
A: DOS itself doesn't support SMP or multiprocessors. Its not impossible to start up additional CPU cores from DOS, but for a multi-core system, please just use another kernel.

Q: Does Xcom supports larger files than 4 GByte?
A: Not yet.

Q: My CD-ROM/DVD-ROM/Blu Ray drive is not visible in XCom.
A: You must install a CD-ROM driver in DOS. XCom itself doesn't includes low-level hardware drivers to access your hardware.

Q: Every drive is listed as existing drive, even if it does not exists.
A: This bug was fixed in 2022.

Q: Are long file names supported?
A: No.

Q: Is NTFS/ext2/whatever supported?
A: You must install a DOS based file system driver for it, and then yes, otherwise no special file systems are supported.
Xcom relies on the kernel (for example, DOS kernel) to do all the file operations.

Q: Directories seem to be separated with / but on DOS, the \ character is the standard separator. What is going on?
A: Xcom uses / characters to separate directories, and it will internally translates them to \ when interacting with DOS.

Q: What is the speed of copying files?
A: It should be at least 1-2 MByte/sec on a 486 DX class computer.
Even if i would try to patch it and make it faster, it is not going to be faster - the BIOS based
file system access DOS is doing, is very slow (CHS or LBA type BIOS interrupts).

Q: Can Xcom be run from a CD, a DVD or a Blu-Ray disc?
A: Yes. Xcom requires no setup, and can run from a read-only media. However, cwsdpmi will try to create a swap file to C if it runs out from RAM. Its not recommended to run Xcom from a CD if you have less than 16 MByte of RAM.
Configuration will not be saved obviously, if you are running the software from a CD-rom.

Q: What is a minimum system to run Xcom?
A: I don't know. For a responsive and fluid experience, a 200 MHz processor is recommended, but it should start up on any 486 and 386 system in theory.

Q: Can Xcom be used with a Hercules graphics card?
A: In theory, it will try to use 720x348 (or 640x350 with EGA), which may requires a video card driver to be installed in DOS.
I was not able to test this, so it will may not work.Hercules, EGA, CGA monochrome modes were tested, and the card types should be autodetected at start in the current version.