---> Mythbusting <--- Myth 1: DOS does not "multitask". Truth: DOS multitasks all the time. Files are read or written while the keyboard is monitored and the clock and screen are updated. DOS can also run multiple programs at the same time if at least all but one are designed to run in the background... THE SAME, AND ONLY WAY, WINDOWS DOES! Myth 2: DOS is restricted to "Full Screen". You cannot display programs in multiple "Windows". Truth: There are several TUI (Textual User Interface) and GUI (Graphical User Interface) shells for DOS that will display programs in multiple "Windows". Many also use the mouse for drag & drop and point & click manipulation. Myth 3: DOS is a "stand alone" operating system. Truth: DOS computers can be networked and can access the Internet (including the world wide web). DOS can even be used as a host for an Internet Server! Myth 4: Point-and-Click is the best way to run a computer. Truth: Command-Line interpreters are the most efficient way to manage files and to run a computer in general. A properly setup DOS system with batch files is more efficient then a GUI for launching programs as well. Besides, most newer DOS programs also support a mouse for Point-and-Click aficionados. Myth 5: All DOS software is old and outdated. Truth: DOS software is still being developed because people are still buying it. Much DOS software is modern, graphical programs, that do not require some bloated OS to run them. Has there ever been an OS more fail-safe than DOS? ================================================== -------------------------------------------------- ---> Alternative to DOS <--- In order to use a DOS program, you need to run it on an Operating System that allows the DOS program to access your computer hardware. Word to the wise: AVOID the Microsoft Windows XP or newer command line to run DOS programs! If you must run DOS programs in Microsoft Windows XP or newer, use vDos, DOSBox, or perhaps VirtualBox if you have a 64-bit system. {Microsoft seems determined to exterminate DOS programs because each successive version of Windows does a poorer and poorer job of supporting them. Windows 98 had the ability to restart in MS-DOS mode. Windows XP went to "heroic lengths" to support DOS applications, but it still introduced many incompatibilities. Windows Vista and Win7 won't run any kind of DOS graphics program. Instead, they pop up the message "This system does not support fullscreen mode." Nothing in the Compatibility mode settings solves the problem. Win7 64-bit is the final straw. It won't even run a one-byte program (RET) that has worked on everything prior - so much for "upward compatibility." DOSBox and virtual machines (such as VMWare or Virtual PC) do provide a partial solution, but they run programs slowly and convulsively, and are certainly not as convenient as simply booting good-old-fashioned DOS (which works fine on 64-bit CPUs). ~~ Loren Blaney} The best Operating System for running DOS programs is IBM OS/2 WARP. With the exception of tools intended to manipulate the file system (and WARP comes with its own suite of tools for the job), I have NEVER encountered a DOS program that did not run flawlessly on WARP. If for some reason you can not install a copy of WARP, then your next best choice is one of the Disk Operating System varients based on IBM/Microsoft PC DOS version 5.0 or later (sorry, Microsoft will no longer help you with anything related to DOS, even if you previously had a paid contract with them for support). A freeware, open-source version of DOS is "FreeDOS" (http://www.freedos.org/index.php). ================================================== -------------------------------------------------- ---> DOS Hardware Guide <--- Like all computer software (including Java software), DOS programs are picky about the hardware they like to run on. Your choices will also depend on whether you want to run new DOS software, or ONLY old DOS software written during the 20th century. Here now are my observations and recommendations, based on personal experience with DOS in the new millennium. Before we begin, you must understand that many DOS programs (especially games) only work properly when run on hardware that is no longer in manufacture. If acquiring used equipment is an issue, then it is best to -not- use DOS software, and settle instead for some alternative. Note that you can "have your cake and eat it too" if you own TWO computers; one for your "normal" software (Windows 2000 works good) and one for your DOS software. Both computers can share the same Keyboard, Monitor, and Mouse by using a KVM switch (thus saving desk space). ----- Computer for running -ONLY- modern DOS software: If all you want to do is run DOS programs written since the turn of the century, then the hardware solution is easy. Just go down to your favorite computer store and buy any computer that strikes your fancy (and that you have all the hardware drivers for). Erase the preloaded software, and install the latest version of your favorite flavor of DOS (or WARP or eComStation). Enjoy. ----- Computer for running -ONLY- vintage DOS software: If all you want to do is run DOS programs written during the 20th century, then the ideal general duty computer processor to select is the Intel 486DX/2 66mhz. Other Intel 486DX, 486DX/2, and 486DX/4 processors of any speed, as well as the fabulous AMD 386DX 40mhz processor, are acceptable alternatives. Ignore everything else. The processors motherboard should support at least two 16-bit ISA peripheral slots (but a micro-channel motherboard without any ISA slots is Ok if you have all the necessary micro-channel peripherals). Make sure the processor has a large heat sink installed. For best thermal cooling, the surface of the heat sink should be smooth and free of paint (use 400grit oiled sandpaper to polish the contact surface of the heat sink if necessary). Always put a layer of thermal paste between the heat sink and the processor (use "Arctic Silver 5"). Install a minimum of 16mb of motherboard Random Access Memory. 32mb is ideal, as that is the limit useable by most older DOS software. The maximum amount of memory DOS can access is 64mb (and you can not even use memory over 64mb for a RAM drive). It is suggested that you do not install MORE than 64mb of RAM in the computer (even if you can), because it may cause addressing errors in some poorly written programs. RAM should be rated at a speed of 60ns or faster (do NOT compromise in the area of RAM speed, or you WILL encounter bizarre computer errors). Do -NOT- mix speeds or types of RAM. Full sized RAM modules using a full complement of discreet chips are preferable to low-profile or reduced-chip-count RAM. -ALWAYS- install RAM in pairs (even if the motherboard will let you install memory singularly). The video card (or onboard video) -MUST- be VGA compatible, and have a MINIMUM of 1mb video ram. Note however that video ram in excess of 2mb is not used by 20th century DOS software. Video card may be of any bus type supported by the motherboard (ISA, VLB, etcetera). The chip must be able to support VESA 1.2 or higher either natively or with a software driver. Ideally the chip should support VESA 2.0 natively. Note that video cards running at slower bus speeds (such as is typical with ISA video cards) will run old DOS games better, as you do not need to add excessive software slowdown tricks to compensate. Be aware that 1mb video cards differ from brand to brand, and sometimes do not conform to SVGA modes used by a specific DOS program (pixelation under the mouse pointer is a common error symptom). Solutions include falling back to standard modes (such as normal VGA), choosing a VESA video mode, or selecting a different brand of video card (best choice). Don't worry about old performance ratings for various brands of old 1mb video cards. These ratings were only important if you were running Microsoft Windows 3.x, Autodesk Autocad, or certain very specialized software applications. For everything else, performance differences were nearly indistinguishable between video card brands/chipsets. Unless the computer will be dedicated to running ONLY one or two very specialized DOS programs, do -NOT- install a monochrome video card. Computer must have at least one 1.44mb 3.5" floppy disk drive. An excellent choice is the Teac model FD235HF (still in production). Configure this drive as drive A:. This is your initial boot drive. Computer must have a hard drive. I would strongly advise NOT using anything smaller than 40mb (megabyte), and using only an MFM, ESDI, or ATA drive. DOS will recognize ONLY 8gb of fixed disk space on a SINGLE drive (but note that you can connect multiple drives, up to the limit of your drive letters). You CAN install a bigger hard drive, but with conventional 16-bit DOS you will not be able to fdisk any of that drive beyond the 8gb barrier. Note however that With the new 32-bit versions of DOS (such as "FreeDOS-32"), the OS can recognize drives up to 136gb, so it wouldn't be a terrible idea to initially install a 120gb drive. Your primary hard drive should be configured as drive C:. Do NOT use a SCSI drive as your primary drive. Also, avoid using "HardCard" or "Bernoulli/Syquest" drives in the computer if possible. Computer must have a parallel printer port (configured as LPT1, IRQ5). Even if you don't have a printer, the port may be needed for hardware copy protection keys. Equip the computer with a 2-button Microsoft compatible mouse or trackball (a 3-button Logitech mouse or trackball is an acceptable alternative). Do NOT use a Genius or Mouse Systems mouse! The mouse can be either a PS/2 mouse (the preferred choice) or serial mouse (serial mice should use COM port 1, IRQ4). It doesn't matter if the mouse has a wheel or not. Naturally the computer will have a keyboard and monitor (or "CONsole" as they used to call it). It doesn't matter whether the keyboard uses the large DIN or PS/2 type plug (you can use a keyboard plug adapter if necessary). For most software you can even use a keyboard that has only 10 function keys. The Monitor should be a SVGA color monitor (15-pin plug), and a multi-sync monitor is preferred. Don't stress your eyes using a monitor smaller than 16-inches diagonal or with a resolution courser than .28 dpi (.30 dpi on giant monitors). It is recommended that the computer be equipped with a CD-ROM drive. 4x speed is sufficient, as none of the older software required anything faster (and in fact, slower drives run quieter and safer). If you can, substitute the CD-ROM with a CD-RW drive. NEC is an excellent brand. If you intend to play games, the computer should be equipped with one joystick port. If the computer has more than one port, the other ports -MUST- be disabled. Ideally you should disable ALL the computers joystick ports and install a dedicated high-performance IDE joystick port card. An excellent high-performance card is the CH Products model "Gamecard 3 Automatic" (still in production). Choose your joystick carefully. Old DOS games can NOT take advantage of many of the features found on modern joysticks (and they will not work at all with joysticks attached to a USB port). A simple X/Y axis joystick with 2-buttons is sufficient for the majority of old DOS games. Whatever joystick you choose, make sure that it is equipped with "trim" controls (the little wheels that allow joystick centering). Games require a sound card (or onboard audio). Sound card MUST be SoundBlaster 16 compatible. A genuine ISA SoundBlaster family card is the preferred choice (some games will not find the sound card if it is NOT installed on an ISA bus, because they use DMA, and DMA is not supported through PCMCIA or Parallel ports). SoundBlaster settings should be A220, I7, D1 (note that I7 is NOT the default on some cards, so it must be changed). To take full advantage of late '90s games, you should use a sound card that is also SoundBlaster AWE32 compatible. Stereo headphones are an excellent choice for listening to sound output. NOTE: The SoundBlaster 16 was backwards compatible to the "original" SoundBlaster, -NOT- the SoundBlaster "PRO"! Genuine SoundBlasters that are AWE32 compatible can often playback General MIDI or Roland (MT-32) sequences through a TSR that re-maps the SoundBlaster sound banks. Optionally a printer should be considered. Some old '80s programs even required them. Most software will print to an Epson LQ1500 compatible 24-pin dot-matrix continuous feed printer. Some software will also support a laser printer compatible with the Apple Laserwriter. If you desire remote connectivity to other computers/devices, then a modem and network interface card should be considered. Your best modem choice is a 33.6kbps V.34bis modem (on COM2, IRQ4). In ideal situations your may get slightly better download speeds with a 56kbps V.92 modem, but the upload speeds are usually slower than with the 33.6kbps V.34bis modem. -NEVER- use a "Win-modem" (they don't work with DOS). Network interface cards should be NE-2000 compatible. 3-Com Etherlink III compatible network interface cards are usually a suitable alternative. Your best choices for an operating system is either pure DOS (any manufacturer) compatible with MS-DOS version 5.0 (MS-DOS 6.22 is a very stable commercial choice, while FreeDOS is a good open source software alternative), or any version of IBM WARP (or the new eComStation). Stick with a 16-bit File Allocation Table (i.e., 8.3 file names) if you are using Pure DOS (WARP users can use any supported file system). According to some software historians, apparently the Microsoft Long File Name implementation was originally leveraged as a method to frustrate DOS users into migrating to Windows (a lot of old DOS file management software will function improperly when faced with Long File Names). If you like the idea of tagging files with descriptive comments, then I suggest you use one of the DOS compatible pre-LFN solutions such as the popular Norton Utilities "File Info". A memory manager that can move drivers into Upper Memory is required, because later software applications needed over 512k of base memory. You must also provide exPanded memory (a page frame), as a lot of applications require it to run. QEMM is an excellent memory manager. Caching software can cause problems with older DOS programs, so it is often better just to run lots of buffers (many old DOS programs are unintelligent in regards to disk caching, and will refuse to run unless you have a minimum amount of buffers anyway, even if you have a huge software disk cache running instead). Now that large fast access hard drives are available, the need for Disk Caching software or Disk Compression (-ALWAYS- shun disk compression) has been eliminated. ----- Computer for running -ANY- DOS software (new or old): A computer that works satisfactorily with both old and new century DOS programs is a difficult thing to design. You must carefully balance on the fence between Performance and Compatibility. Practical experience has shown what works and what does not. For this type of computer, it is best to use the specific parts (or equivalents) I will be suggesting in the following paragraphs. ISSUES: The motherboard will have to support the Pentium class of processors. Why? Because it was not until the pentium was released that the PCI Local Bus became available. A PCI bus is MANDATORY, because the newest hardware devices are not available in older Bus designs (and remember, DOS can run virtually all new PHYSICAL hardware standards just fine). However, the Pentium class of processors are not the best choice for most DOS software. Why? Because of the integrated Cache. This often causes problems in several ways, the biggest being that much DOS software expected the processor to be constantly looking for changes in the state of the hardware device or software instructions. When the processor only referres to old data in its cache, dynamic changes can not be implemented. New software understands the new processors and sends special instructions to flush the processor cache. However much DOS software cannot issue these commands, and you will instead get errors such as sound synchronization issues, video updates not taking place, random program crashes, and slowdown software producing inconsistent slowing depending on what the program is currently doing. Experiments should be made as to whether an individual program will run better without the cache being active, and a batch file should be written to enable/disable the cache when the program is launched. Another problem faced, and to which the Pentium processors play a major role, is that of computing speed. Much DOS software old and new is written using efficient low level coding languages. These languages produce small, fast programs that do not require high performance hardware to make them run effectively. The DOS programmers were not expecting the onslaught of sloppy, bloated code that defines much of the non-DOS software written today. They had assumed (incorrectly) that persons writing such code would fall to the wayside because their programs would run very poorly on existing hardware. The did NOT anticipate that the hardware manufacturers would compensate for the programmers shortcomings by offering higher processing speeds (and as a side issue, bigger storage). There are two major speed related problems. Old DOS programs will often run way above their expected speeds (good for Word Processors, bad for Arcade Games). Adding hardware bottlenecks and using software slowdown trickery can help compensate. A worse problem is that some DOS software was written on a compiler that produced code that will crash when a processor reaches a certain speed (usually around 200mhz). The only solution for this problem is to either re-compile the software using a more modern compiler (often not possible due to the unavailability of the original uncompiled software code) or keep the processor speed under about 199mhz. Increases in storage space has been an advantage and a curse. The advantage is that DOS programs no longer have to consider bizarre techniques for storing large quantities of data (Drive Compression software, ability to write to tape drives, programs that slice files into smaller chunks, etcetera). The curse is that with all that storage space, DOS programmers are forgoing writing small, efficient code, and they are including lots of "extras" in their programs that eat up considerable amounts of storage space. DOS (being 16-bits) does have limits that are being quickly reached (i.e., the 8gb drive limit). Finally, the history of PC computing itself has forced issues into DOS programs. Many DOS programs were written during a period of great flux in the kinds of hardware available for DOS to operate on. As hardware standards changed, there was often little or no support for the older standards. Software vendors compensated by offering duplicate code inside their programs that allowed them to be run on the older hardware (that's why you often must first tell your programs what kind of Video card, Sound card, etcetera, is installed). However, older software is not "forward" compatible, so a program written to operate only on a CGA video card for example, may not work properly when all you have in the computer is a VGA video card. Hardware selection for an all-purpose DOS computer therefore becomes a careful balancing act of selecting parts that will work with -MOST- software. A REPORT FROM THE TRENCHES: It was long a goal of mine to create the "ultimate" DOS computer. I wanted a computer that would run all kinds of classic 20th century software, but still be able to run the latest new-millenium gadgetry. Constant testing and tweeking has lead to the following computer. I suggest building something similar and you will not be dissapointed. PROCESSOR = Intel Pentium MMX, 166mhz, with premium passive heat-sink. The Intel pentium works better with DOS software than does the AMD or Cyrix processors. Although MMX is somewhat of a non-issue for DOS programs, the die runs cooler and more efficeintly than does the older non-MMX Pentium processors (your motherboard will last longer if the processor heat is reduced). The 166mhz was the slowest of the MMX processors (an important consideration for older DOS software), and you will NOT experience the 200mhz glitch. On the other hand, it is fast enough that modern multi-media software (such as MP3 players) will run satisfactoraly. A heat-sink is MANDITORY, and between it and the processor should be a layer of thermal paste (use the "Arctic Silver 5" brand exclusively). A passive heat-sink is preferred -IF- you have sufficient airflow across the heat sink; as it creates a quieter computer, and more importantly, there is no fan to fail (and fail the fans ALWAYS do!). MEMORY = 64Mb, 60ns, premium grade, installed in equally-balanced banks. Although nearly all software should work satisfactorally with only 32Mb of RAM, a few modern software programs can take advantage of the extra memory. Even if you don't use one of these programs, you could still take advantage of the extra memory by, for example, using it to make a small RAM drive. NEVER scrimp on RAM quality. Use ONLY premium grade RAM, and never use anything UNDER 60ns with a Pentium processor. Banks should be filled evenly, and with the SAME Brand and Type of RAM. BUS SPEED = PCI at 33mhz (66mhz FSB), ISA at 8.33mhz If you were using a faster Pentium, I would underclock the PCI bus to 25mhz. However with the 166mhz Pentium, the standard bus speed does not adversely speed-up older software, yet it allows satisfactory throughput for modern multi-media software. As you will probably be using the PCI bus rather than the ISA bus for modern peripherials, there is no need to increase the ISA bus speed (ISA peripherals tend to go unstable over 8.33mhz anyways). On the other hand, slowing the ISA bus could potentially cause unacceptable sluggishness. POWER SUPPLY = Premium grade, high wattage (PC Power and Cooling brand was the old standard in high performance power supplies). Pentium, Pentium II, and Pentium III computers are notoriously sensitive to inferior power supplies. Upgrading these older computers with a premium grade power supply will garner imediate stability rewards, and mysterious glitches will vanish. I was using an older PC Power and Cooling brand power supply, as this brand was the performance leader in its day. Now however I exchanged this power supply for one of the new generation "Quiet Fan" power supplies. The power supply fan (with the possible exception of the hard drive) is the noisiest component in the computer. Quiet computing is a VERY important aspect of computing (as much as choosing a proper monitor or an ergonomic keyboard). Be careful though to make sure that the power supply is not just quiet, but also of Premium Grade (i.e., uses large capacitors, beefy components, and lots of heat-sinking, so it can effectively deliver a CLEAN high wattage output without strain). The Nexus NX-3500 with a bottom-mounted 120mm fan is the one I chose. ALWAYS use a surge protector, but if possible, use a UPS instead. MOTHERBOARD = Late model (Intel brand AN430TX). I am using a newer motherboard that contains both 16-bit ISA and PCI peripheral slots. As an asside, the motherboard also contains a soundblaster compatible onboard sound chip, an onboard SVGA chip, and onboard Parallel, Serial, Joystick, PS/2 mouse, and USB sockets. Any quality ISA/PCI motherboard should be acceptable, and if for some reason you cannot get a combo-slot board, you may even be able to get by with a pure PCI slot motherboard. The motherboard I am using is the Intel AN430TX. I have found this board to be an excellent performer, and you would be well served to choose something comparable. HARD DRIVE = Modern LOW NOISE parallel ATA/66 hard drive (I am using a quiet ATA/100 120Mb Seagate ST3120814A with 8Mb cache). Using a quiet hard drive is a major component for creating a silent PC. Although DOS can only access a maximum of 8Gb, quiet low capacity hard drives are not being manufactured, so its ok to use a larger capacity drive (I would recommend however NOT using a drive larger than 137Mb, due to this being a native FAT32 barrier and a possible issue with your motherboard BIOS). Note that for Parallel ATA/66 and ATA/100 drives you must use a special controller and ribbon cable (If your bult-in controller does not support these bus speeds, you can install high speed peripheral controller card). You also need to load a driver so DOS can use UDMA for data transfers. Choose a hard drive with the highest capacity hardware cache. This will allow you to eliminate the need for memory wasting software caches. Heat is deadly for hard drives, so always make sure your drive is sufficiently cooled. FLOPPY DRIVES = separate 1.44mb 3.5" and 1.2mb 5.25" (TEAC brand). I have both the 1.44mb and 1.2mb floppy drives installed. I use the TEAC brand as this brand is the best. Don't scrimp here and buy just any old floppy drive, as one glitch and your diskette is dead! There is no need for a 2.88mb floppy drive as the blank diskettes are VERY difficult to acquire and commercial software was never released on them. Today much software that was formerly released on 1.2mb diskettes has been transferred onto 1.44mb diskettes or CD, so the 1.2mb diskette drive COULD be eliminated. CDROM = CD/R drive, 32X read and DVD drive, 8X read. A CDROM drive is mandatory. I suggest the drive that uses a tray rather than a drive that uses a cartridge. The NEC brand drives are fantastic. Try to get a drive that reads between 4X and 32X. Slower drives are too slow, but faster drives are both VERY noisy and may cause explosive CD failure! I highly reccomend a CD/R or CD/RW drive, as it is VERY convenient to write large data chunks to a CD rather than a stack of floppy diskettes. A modern DOS computer should also be equipped with a DVD reader. A DVD writer is not required at this time in history, and although I am using a separate CD and DVD, you could use a combo unit. An excellent combo unit is manufactured by BenQ. If your CD still uses PIO mode for data transfers (a typical situation), it is recommended that you install it on a separate controller channel from that used by UDMA devices such as your Hard Drive. JOYSTICK PORT = high performance (CH Products Gamecard 3 Automatic). Built-in or conventional joystick/game ports are insufficient to work with the combination of DOS and a Pentium processor. If you use a joystick, you MUST upgrade to a high performance gamecard (modern USB joysticks and other game controllers will NOT work with DOS). The best card to use is the CH Products brand "Gamecard 3 Automatic". Note that this card is ONLY available in ISA (and at one time, MicroChannel). SOUND = SoundBlaster AWE32 compatible. I am using a genuine SoundBlaster Gold ISA sound card. Any quality compatible that uses an ISA bus, or is in the form of a chip built onto the motherboard, should work. Do NOT use a PCI sound card, as DOS has trouble accessing soundcards properly through a PCI interface. Don't use cheapo speakers. Quality headphones are a better choice. DATA PORTS = Serial, Parallel, and USB. My motherboard has a parallel, serial, and USB port built-in. If yours does not, you can add these ports by installing peripheral cards. The Serial port is fairly optional, and will probably only be used if you have an outboard Modem. The Parallel port is mandatory, as even if you do NOT have a printer, you may have to use this port to install copy-protection keys. As for the choice of printer, I highly recommend an HP brand LaserJet 4. Do NOT use a USB printer, as DOS programs will not be able to print to a USB port. I DO recommend having a USB port, as you can use USB storage devices (such as jumpdrives) with DOS. Note that DOS will also work with Firewire (and you can obtain Firewire preipheral cards if necessary), but unless you have a specific need, just having USB capability will be sufficient. FLASH CARD READER = Addonics CF compatible. Addonics makes the Addonics CF, a DOS compatible flash card reader. I strongly recommend that a flash card reader be installed, because it allows downloading of camera images and is more convenient than floppy disks for transferring data (flash cards are higher capacity). The drive may have to reside on its own controller channel however. USER INTERFACE = Modern keyboard, modern mouse, large SVGA monitor. Use a modern keyboard that has all 12 F-keys. A "left-hand" keyboard (one with the keypad on the left of the alphanumeric keys) will produce less stress on your arm by allowing the mouse to be located closer to the alphanumeric keys. Use only a Microsoft or Logitech PS/2 mouse. The Monitor can be either a CRT or flat panel (the CRT will cause LESS eyestrain over long periods). Naturally the monitor should be a modern SVGA monitor, but make sure it is at least 17" diagonal. NETWORK INTERFACE = Realtek RTL8139D chip [NE2000] compatible. A network interface is not mandatory, but necessary if you want to access internet resources such as FTP, Gopher, and Web sites. The NIC should be either onboard or use the PCI bus for better throughput. The Realtek RTL8139D chip is a modern NE2000 compatible chip that is compatible with most Novell and WATTCP software. VIDEO = SVGA, VESA 2.0 compatible, 1mb VRAM. The video card is the most difficult component to properly interface with DOS and DOS software. 1mb of VRAM is sufficient, and the card should be VESA 2.0 compatible for maximum flexibility. Other than that, be aware that an old ISA video card, due to its operating at a slower bus speed and equipped with slower VRAM, will often play DOS games much better than PCI or onboard video cards. As for the best choice, I still do not know. I have tried several different brands and models, and I have yet to find one card that works with all DOS software flawlessly (there is always something; either the card runs too fast, it is not compatible with certain video modes, or it "pixelates" in SVGA mode). Currently I am using a Tseng ET4000 chip video card, as it is compatible with a very wide selection of DOS programs and games. ---------- So there you have it. For single-tasking, DOS still has a lot of potential. Build up one of these machines described here, and have fun!