Difference between revisions of "Intel CPUs"

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(Emulation issues: Get rid of this because NO EMULATOR EMULATES DOS)
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There's an MS-DOS-compatible replacement still in active development called FreeDOS. Every program written for MS-DOS can be run under FreeDOS, and every platform capable of running MS-DOS should be supported by FreeDOS. Several bugs inherent in MS-DOS even on older machines are no longer present, and it's open source software. It's an advisable alternative that, even if older computers can run it, is just as usable on modern computers; keep in mind most software, particularly early DOS programs based on the CGA or Tandy video standards, will not run acceptably on modern hardware without CPU downclocking tools and roughly compatible video and sound hardware. There are other versions of DOS with continued support such as DR-DOS, but their codebase is proprietary and they don't include nearly as many features as FreeDOS. Microsoft has released [https://github.com/microsoft/ms-dos/ the first two versions of MS-DOS] has open-source.
 
There's an MS-DOS-compatible replacement still in active development called FreeDOS. Every program written for MS-DOS can be run under FreeDOS, and every platform capable of running MS-DOS should be supported by FreeDOS. Several bugs inherent in MS-DOS even on older machines are no longer present, and it's open source software. It's an advisable alternative that, even if older computers can run it, is just as usable on modern computers; keep in mind most software, particularly early DOS programs based on the CGA or Tandy video standards, will not run acceptably on modern hardware without CPU downclocking tools and roughly compatible video and sound hardware. There are other versions of DOS with continued support such as DR-DOS, but their codebase is proprietary and they don't include nearly as many features as FreeDOS. Microsoft has released [https://github.com/microsoft/ms-dos/ the first two versions of MS-DOS] has open-source.
 
==Emulation issues==
 
===OS support===
 
Many PC emulators do not support multiple operating systems, as this requires a much more low-level emulation of the hardware, which is often difficult to nigh-impossible to achieve. The only listed LLE PC emulator is PCem (SIMH is LLE but does not emulate PC hardware, see [https://en.wikipedia.org/wiki/SIMH#Emulated_Hardware here] for emulated hardware), which is not only able to run DOS and Windows up to XP, but also Linux, BeOS, and various other obscure OSes.
 
 
===Screen tearing===
 
DOS games had no vertical synchronization to speak of. DOS-focused emulators such as DOSBox and its forks have issues with V-sync implementation. Even outputting to a CRT at their native modeline (320x200@70Hz, scaled up to 640x400), users report screen tearing.
 
 
===CPU clock speed===
 
The difference between an early DOS game and a late DOS game in terms of the hardware they were intended to be run under is quite vast. This occasionally leads to certain problems with games running too fast or too slow even through emulation. DOSBox includes settings for adjusting clock speed and often does it automatically, although occasionally DOSBox does not choose an acceptable clock speed and the user has to manually change the settings.
 
  
 
==References==
 
==References==

Revision as of 17:17, 17 November 2018

The IBM Personal Computer is the original name of the PC architecture. The first model, the IBM PC 5150, was released in 1981. Over the course of thirty years, it and "IBM PC-compatibles" began to dominate the enterprise and consumer world thanks to IBM's move to use an open architecture, which allowed a ton of add-ons and peripherals to form markets of their own.

Emulators

PC
Name Operating System(s) Latest Version 8086 emulation 286 emulation 386 emulation 486 emulation Pentium emulation* Active Recommended
86Box Windows Git
PCem Windows, Linux 14
DOSBox Multi-platform 0.74-2
SVN
DOSBox-X Multi-platform 0.82.10 ? ? ?
SIMH Multi-platform 3.9-0 ? ? ? ? ?
MAME Multi-platform 0.264 ? ? ? ? ?
PCjs Multi-platform Git ? ? ? ? ?
DOSEmu Linux 1.4.0 ? ? ? ? ?
DOSEmu2 Linux 2.0pre8 ? ? ? ? ?
QEMU Linux, macOS, and Windows 2.11.1 ? ? ? ? ? ? ?
Bochs ? ? ? ? ? ? ? ? ?
Mobile
DOSBox Multi-platform 0.74
SVN
aDOSBox Android 0.2.5 ? ? ? ? ?
AnDOSBox Android 1.2.8 ? ? ? ? ?
DosBox Turbo Android 2.2.0 ? ? ? ? ?
gDosBox Android 0.7.5.5 ? ? ? ? ?
Magic Dosbox Android 1.0.61 ? ? ? ? ?
QEMU Android 2.11.1 ? ? ? ? ? ? ?

*Pentium emulation includes MMX variants and the Pentium II.

Models

IBM PC/XT

Short for the IBM Personal Computer XT 5160, the PC/XT was a version of the IBM PC with a built-in hard drive released on March 8, 1983. Apart from the Winchester disk, it was essentially the same as the original PC, with only minor improvements. The XT was mainly intended as an enhanced IBM PC for business users. Later floppy-only models would effectively replace the original model 5150 PC. A corresponding 3270 PC featuring 3270 terminal emulations was released later in October 1983. Later, the PC/AT 5170 was released with many enhancements, the most major of which was probably the 286 processor. This allowed a 16-bit bus, which is why 16-bit ISA cards will only work on AT or newer, though some XT-class machines have the older 8086 processor, which also allows for a 16-bit bus, and therefore 16-bit ISA cards.

Software

DOS

MS-DOS logo

DOS (Disk Operating System) was the common name for text-based operating systems used by the early microcomputers that was either specific in usage, or very broad like a generic label or descriptor. What most people know as DOS is probably MS-DOS, and lesser-known compatibles like DR-DOS and PC-DOS that are all rooted in the first operating system ever written for the platform, Gary Kildall's Control Program for Microcomputers (CP/M). Many companies had their own version of DOS across many platforms, but Microsoft set the standard with MS-DOS when it was released in 1981 for IBM PCs. The others were generally compatible with software marketed for MS-DOS, in order to stand any chance at competing. The last standalone release of MS-DOS is version 6.22; updated versions of it were later integrated into Windows 9x.[1]

There's an MS-DOS-compatible replacement still in active development called FreeDOS. Every program written for MS-DOS can be run under FreeDOS, and every platform capable of running MS-DOS should be supported by FreeDOS. Several bugs inherent in MS-DOS even on older machines are no longer present, and it's open source software. It's an advisable alternative that, even if older computers can run it, is just as usable on modern computers; keep in mind most software, particularly early DOS programs based on the CGA or Tandy video standards, will not run acceptably on modern hardware without CPU downclocking tools and roughly compatible video and sound hardware. There are other versions of DOS with continued support such as DR-DOS, but their codebase is proprietary and they don't include nearly as many features as FreeDOS. Microsoft has released the first two versions of MS-DOS has open-source.

References