PCem (short for PC Emulator) is an

IBM PC The IBM Personal Computer (model 5150, commonly known as the IBM PC) is the first microcomputer released in the IBM PC model line and the basis for the IBM PC compatible de facto standard. Released on August 12, 1981, it was created by a tea ...

emulator In computing, an emulator is hardware or software that enables one computer system (called the ''host'') to behave like another computer system (called the ''guest''). An emulator typically enables the host system to run software or use peri ...

for Windows and Linux that specializes in running old operating systems and software that are designed for IBM PC compatibles. Originally developed as an

IBM PC XT The IBM Personal Computer XT (model 5160, often shortened to PC/XT) is the second computer in the IBM Personal Computer line, released on March 8, 1983. Except for the addition of a built-in hard drive and extra expansion slots, it is very simila ...

emulator, it later added support for other IBM PC compatible computers as well. A fork known as '' 86Box'' is also available, which includes a number of added features, such as support for SCSI and additional boards. On 14 June 2021, lead developer Sarah Walker announced her departure from the project. A new maintainer, Michael Manley, was appointed on 18 December 2021. During the interim period with no maintainer, the project's forums were closed.

Features

Hardware

PCem is capable of emulating Intel processors (and its respective clones, including AMD, IDT and

Cyrix Cyrix Corporation was a microprocessor developer that was founded in 1988 in Richardson, Texas, as a specialist supplier of floating point units for 286 and 386 microprocessors. The company was founded by Tom Brightman and Jerry Rogers. In 1992 ...

) from

Intel 8088 The Intel 8088 ("''eighty-eighty-eight''", also called iAPX 88) microprocessor is a variant of the Intel 8086. Introduced on June 1, 1979, the 8088 has an eight-bit external Bus (computing), data bus instead of the 16-bit computing, 16-bit bus of ...

through the Pentium ''Tillamook'' MMX/Mobile MMX processors from 1997 until 1999. A recompiler has been added in v10.1, being mandatory for P5 Pentium and Cyrix processors and optional for i486 processors and IDT WinChip processors. Yet a rather fast processor is needed for full emulation speed (such as an

Intel Core i5 The following is a list of Intel Core i5 brand microprocessors. Introduced in 2009, the Core i5 line of microprocessors are intended to be used by mainstream users. Desktop processors Nehalem microarchitecture (1st generation) "Lynnf ...

at 4 GHz). However, the current developer of PCem has a main concern that the recompiler is not fast enough to emulate the Intel Pentium Pro/Pentium II processors yet. PCem emulates various IBM PC compatible systems/motherboards from 1981 until 1996, this includes almost all IBM PC models (including the IBM PS/1 model 2121 and the IBM PS/2 model 2011), some American Megatrends BIOS clones (from 1989 until 1994), Award BIOS systems (Award 286 clone, Award SiS 496/497 and Award 430VX PCI), and Intel Premiere/PCI and Intel Advanced/EV motherboards. However, unofficial builds of PCem (PCem-X and PCem-unofficial) also supports IBM PC compatible systems/motherboards (from 1996 until 2000) that supports Intel Pentium Pro/Pentium II processors. PCem simulates the BIOS cache, which relies on the processor rather than on system memory. PCem can emulate different graphic modes, this includes

text mode Text mode is a computer display mode in which content is internally represented on a computer screen in terms of characters rather than individual pixels. Typically, the screen consists of a uniform rectangular grid of ''character cells'', each o ...

Hercules Hercules (, ) is the Roman equivalent of the Greek divine hero Heracles, son of Jupiter and the mortal Alcmena. In classical mythology, Hercules is famous for his strength and for his numerous far-ranging adventures. The Romans adapted th ...

, CGA (including some composite modes and the 160 × 100 × 16 tweaked modes), Tandy, EGA,

VGA Video Graphics Array (VGA) is a video display controller and accompanying de facto graphics standard, first introduced with the IBM PS/2 line of computers in 1987, which became ubiquitous in the Personal computer, PC industry within three years ...

(including

Mode X Mode X is an alternative 256-color graphics display mode of the IBM VGA graphics hardware that was popularized by Michael Abrash. It was first published in July 1991 in '' Dr. Dobb's Journal'', and republished in chapters 47-49 of Abrash's ''Gra ...

and other tweaks),

VESA VESA (), formally known as Video Electronics Standards Association, is an American technical standards organization for computer display standards. The organization was incorporated in California in July 1989To retrieve the information, sear ...

, as well as various video APIs such as DirectX and 3Dfx's Glide. PCem can also emulate various video cards such as the ATI Mach64 GX and the S3 Trio32/64/Virge series. PCem also emulates some sound cards, such as the

AdLib Ad Lib, Inc. was a Canadian manufacturer of sound cards and other computer equipment founded by Martin Prevel, a former professor of music and vice-dean of the music department at the Université Laval. The company's best known product, the ''A ...

Sound Blaster Sound Blaster is a family of sound cards designed by Singaporean technology company Creative Technology (known in the US as Creative Labs). Sound Blaster sound cards were the de facto standard for consumer audio on the IBM PC compatible system ...

(including the Game Blaster), Sound Blaster Pro,

Sound Blaster 16 The Sound Blaster 16 is a series of sound cards by Creative Technology. They are add-on boards for PCs with an ISA or PCI slot. Sound Blaster 16 Sound Blaster 16 (June 1992), the successor to the Sound Blaster Pro, introduced CD-quality di ...

Sound Blaster AWE32 The Sound Blaster AWE32 is an ISA sound card from Creative Technology. It is an expansion board for PCs and is part of the Sound Blaster family of products. The Sound Blaster AWE32, introduced in March 1994, was a near full-length ISA sound ...

, Gravis UltraSound, Innovation SSI-2001, Aztech Sound Galaxy Pro 16,

Windows Sound System Windows Sound System (WSS) is a sound card specification developed by Microsoft released at the end of 1992 for Windows 3.1. WSS featured support for up to 16-bit, 48 kHz digital sampling, beyond the capabilities of the popular contemporary ...

Ensoniq AudioPCI The Ensoniq AudioPCI is a PCI-based sound card released in 1997. It was Ensoniq's last sound card product before they were acquired by Creative Technology. The card represented a shift in Ensoniq's market positioning. Whereas the Soundscape line ...

64V/ES1371, and Sound Blaster PCI 128. Voodoo cards are also emulated since PCem v10 and PCem v12, which added support for Voodoo 2 and various optimizations. However, there are some shortcomings regarding Voodoo emulation such as the lack of mipmapping, slightly wobbling triangles, lack of speed limiting, and inaccurate refresh rates on almost every resolution (except 640 × 480@60 Hz). As of PCem v11, a separate recompiler has been added for Voodoo emulation, making it faster to emulate the Voodoo graphics card. An unofficial build of PCem allows usage of

SLiRP Slirp (sometimes capitalized SLiRP) is a software program that emulates a PPP, SLIP, or CSLIP connection to the Internet using a text-based shell account. Its original purpose became largely obsolete as dedicated dial-up PPP connections and b ...

/ WinPcap as a networking interface, plus emulated NE2000 and

Realtek Realtek Semiconductor Corp () is a fabless semiconductor company situated in the Hsinchu Science Park, Hsinchu, Taiwan. Realtek was founded in October 1987 and subsequently listed on the Taiwan Stock Exchange in 1998. Realtek currently manufa ...

RTL8029AS Ethernet cards. However, starting with PCem v13, the emulation of NE2000 was officially added.

Operating system support

Similar to Virtual PC,

Bochs Bochs (pronounced "box") is a portable IA-32 and x86-64 IBM PC compatible emulator and debugger mostly written in C++ and distributed as free software under the GNU Lesser General Public License. It supports emulation of the processor(s) (includi ...

and

QEMU QEMU is a free and open-source emulator (Quick EMUlator). It emulates the machine's processor through dynamic binary translation and provides a set of different hardware and device models for the machine, enabling it to run a variety of g ...

, it emulates almost all versions of Microsoft Windows until

Windows Vista Windows Vista is a major release of the Windows NT operating system developed by Microsoft. It was the direct successor to Windows XP, which was released five years before, at the time being the longest time span between successive releases of ...

(including Service Pack 2),

MS-DOS MS-DOS ( ; acronym for Microsoft Disk Operating System, also known as Microsoft DOS) is an operating system for x86-based personal computers mostly developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, and a few oper ...

FreeDOS FreeDOS (formerly Free-DOS and PD-DOS) is a free software operating system for IBM PC compatible computers. It intends to provide a complete MS-DOS-compatible environment for running legacy software and supporting embedded systems. FreeDOS ca ...

and

CP/M-86 CP/M-86 was a version of the CP/M operating system that Digital Research (DR) made for the Intel 8086 and Intel 8088. The system commands are the same as in CP/M-80. Executable files used the relocatable .CMD file format. Digital Research al ...

are also supported. Earlier versions of

OS/2 OS/2 (Operating System/2) is a series of computer operating systems, initially created by Microsoft and IBM under the leadership of IBM software designer Ed Iacobucci. As a result of a feud between the two companies over how to position OS/2 ...

requires the hard drive to be formatted prior to installation, while OS/2 Warp 3 until Warp 4.5 requires an unaccelerated video card to run. Other operating systems are also supported on PCem, such as versions of

Linux Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which i ...

that supports the Pentium processor, BSD derivatives (e.g.

FreeBSD FreeBSD is a free and open-source Unix-like operating system descended from the Berkeley Software Distribution (BSD), which was based on Research Unix. The first version of FreeBSD was released in 1993. In 2005, FreeBSD was the most popular ...

), and BeOS 5, which only works on the Award SiS 497 motherboard.

Version history

Versions of PCem from v0.5 until v8 have been removed from the official webpage, due to the use of the

MAME MAME (formerly an acronym of Multiple Arcade Machine Emulator) is a free and open-source emulator designed to recreate the hardware of arcade game systems in software on modern personal computers and other platforms. Its intention is to preserv ...

OPL2 The OPL (FM Operator Type-L) series are a family of sound chips developed by Yamaha. The OPL series are low-cost sound chips providing FM synthesis for use in computing, music and video game applications. Internal operation The internal operati ...

OPL3 The OPL (FM Operator Type-L) series are a family of sound chips developed by Yamaha. The OPL series are low-cost sound chips providing FM synthesis for use in computing, music and video game applications. Internal operation The internal operation ...

emulation code from when it was not yet licensed under a

GPL The GNU General Public License (GNU GPL or simply GPL) is a series of widely used free software licenses that guarantee end users the four freedoms to run, study, share, and modify the software. The license was the first copyleft for general us ...

-compatible license.

References

{{Virtualization products 2007 software DOS emulators DOS on IBM PC compatibles Free emulation software Free software programmed in C Linux emulation software Windows emulation software X86 emulators

Features

Hardware

Operating system support

Version history

See also

References