Have you ever run Doom below system requirements?

[Koko Ricky]

It's a damn mess. I remember in 1994, when my dad, despite my warnings, installed Doom on our wimpy 386, which had a whopping 20 megahertz of clock speed and four whole megs of RAM! I played Doom in low-res mode with a decreased screen size for a few years, listening to those PC speaker sounds with no music. In a way I almost miss it.

[Maes]

-------------------------------------------------------------
SYSTEM REQUIREMENTS
-------------------------------------------------------------
DOOM(TM) requires an IBM compatible 386 or better with 4 megs of
RAM, a VGA graphics card, and a hard disk drive. A 486 or
better, a Sound Blaster Pro(TM) or 100% compatible sound card
is recommended. A network that uses the IPX protocol is
required for network gameplay.

There's a slight difference between "required" and "recommended" specs.

A 386 is well withing the "minimum" game requirements. The only way to run it "below system requirements", would be trying to run in with less than 4 MB of addressable memory, which is impossible to do under DOS, or with a not-so-quite 386 CPU.

Mind you, whether it's really enjoyable or merely "executable" on a low-end 386 or even a low-end 486 (33 MHz or lower) is also debatable. 4 MB of RAM also don't leave much headroom for large levels or heavy modifications, and disk trashing fucks things up.

id later on made those specs a bit more precise (e.g. 386 @ 25MHz as a minimum, while for Doom 2/Final Doom they recommended a 486 and 8 MB of RAM straight away, even though it still worked with 4) but the only hard and fast requirements for playing Doom was having a machine running DOS, having an i386 compatible CPU, and 4 MB of RAM (and of course, enough HD space to store Doom).

[Gez]

I had a 386DX40. 386DX (an AMD exclusivity; Intel just had 386 and used the SX and DX suffixes only for 486) were slightly beefed-up 386 with a maths coprocessor. It was okay overall. Some areas in large maps (e.g. E1M7) were a bit slow. The framerate was probably less than a constant 35, but it was still enough to be playable at the time. Low-detail mode didn't seem to do much to help, and reducing the view window size (screenblocks) only seemed to have an effect speed-wise when making it truly ridiculously small.

On the other hand, Wolf-3D was very fast and smooth, and an early version of Ken's Lab 3D was deemed unplayable by my brother because he felt it was too fast and it gave him motion sickness.

[Maes]

Gez said:

Intel just had 386 and used the SX and DX suffixes only for 486

Uhm... Intel_80386#The_i386SX_variant. Seems like a legitimate Intel design to me ;-) h

Also, I think you're confusing the DX/SX designations here:

• 386SX: crippled 386 with 16-bit bus.
  
• 386DX: full-fledged 386, but no math co-pro. Needed external 387 chip.
  
• 486SX: crippled 486, full 32-bit but no math co-pro. Needed external 487 chip (which sucked, because it was actually a full-fledged 486)
  
• 486DX: full-fledged 486 WITH BUILT-IN MATH CO-PRO.
  

For Doom anyway, a math co-pro made no difference. For DEU, that's another matter ;-)

OTOH, there were some real bastard designs out there, like my infamous 486DLC, which was really a 386-mobo compatible 486, and some other weird stuff.

[Coopersville]

Once at the home of a distant aunt. I had it minimized to the smallest screen size.

[Technician]

No.

[Use]

The very first time I saw Doom it was on a badly underpowered laptop. It was e1m4, and I wasn't impressed.

[DoomUK]

My first PC was a hand-me-down from my old neighbour who had bought a better computer and was going to throw it out anyway. Can't remember what was inside it but it was too slow to run Doom in fullscreen.

Curiously, Quake ran fine on it at the same screen resolution.

[Bucket]

Yes. My dad used to have a 486DX-50 laptop with 8MB of RAM and VGA graphics (in B&W). Sure, on paper it's well above the minimum specs but in practice it ran quite slow.

[Melon]

Does nuts.wad count?

[Vordakk]

Bucket said:

Yes. My dad used to have a 486DX-50 laptop with 8MB of RAM and VGA graphics (in B&W). Sure, on paper it's well above the minimum specs but in practice it ran quite slow.

Really? My first PC was a 486-33mhz with 8 megs RAM and DOOM ran perfectly on it. So did Heretic and Hexen. I even ran Duke Nukem 3D pretty well on that thing. I remember being so pissed when I found out Quake would never work on it though.

[fraggle]

I certainly remember running Doom on a 386. It was unplayably slow, even at the smallest screen size.

[PRIMEVAL]

Nope. If we had Doom back in the day (I know we had Wolfenstein3D and I vaguely recall seeing a pump action shotgun reminiscent of Doom). First time I remember playing Doom was on the SNES, so that could be in a way below the requirements.

[CODOR]

Maes said:
OTOH, there were some real bastard designs out there, like my infamous 486DLC, which was really a 386-mobo compatible 486, and some other weird stuff.

Heh, a 33MHz one of those was my primary PC from 1993 to 1997. Although that motherboard no longer exists (and I'm not sure what happened to the processor), from what I remember Doom ran acceptably with a slightly smaller screen in high-detail mode (or a full-sized screen at low detail).

I'm fairly certain I had to upgrade to a whopping 8MB of RAM when I installed Doom II, though...

[Technician]

PRIMEVAL said:

Nope. If we had Doom back in the day (I know we had Wolfenstein3D and I vaguely recall seeing a pump action shotgun reminiscent of Doom). First time I remember playing Doom was on the SNES, so that could be in a way below the requirements.

Flats are for suckers.

[TwinBeast]

Well, it used to take 10 minutes to load the game and then I had to play it in the smallest screensize, or with low detail option I could increase the size by some centimetre or two.

Then it was always really nice to test levels and notice textures are misaligned, quit the game after 30s, go back to editor, adjust the alignment, wait 10min, check the level, notice the textures are still misaligned, argh!

Though because of that I started to always put monsters and stuff into the levels, so that I would at least have something else to do in the level than just check some texture alignment or if some lift/door/whatever worked.

[Technician]

Jimi said:

Then it was always really nice to test levels and notice textures are misaligned, quit the game after 30s, go back to editor, adjust the alignment, wait 10min, check the level, notice the textures are still misaligned, argh!

You can certainly understand why texture alignments weren't so perfect on old-school wads. I can't even fathom having to do it without 3D mode let alone waiting more than thiry seconds for the game to boot-up.

[Koko Ricky]

It almost gives me a headache trying to fathom not being able to see what you're doing until you actually test the map. No one would put up with that in 2011.

[hex11]

In 1993 (or maybe early 1994), one of my roommates had Doom on his 386SX/16. It "ran" in a postage stamp sized window, with no sound. I wasn't impressed (you could barely tell what was going on in the game...)

My first PC was a 486DX/33, which ran Doom perfectly. Doom II had some slowdown on MAP30 though, until I upgraded to 8 MB RAM.

[Koko Ricky]

I suddenly remember playing "Rise of the Triad" at an electronics store around '94 or '95. I got motion sickness and actually had a goddamned seizure and fell the fuck over. My dad said my face was white and my lips were blue. Only time that's ever happened! But hey, I was like 10 or something. Maybe I was too young to handle psuedo-3D games. 'Cept I had already played "Doom" and "Wolfenstein 3D" by that point so I dunno.

[Dragonsbrethren]

I have no idea what kind of PC my friend had at the time, but he got a copy of Doom 2 for his birthday and I remember playing it with the screen size down 2 or so, just to get it running a little faster in some parts.

[Maes]

When in the minimum specs it says "VGA card", you should make that a "fast VGA card". With the above mentioned 486DLC, the main bottleneck was the ISA VGA card it had to use as nothing but a dumb framebuffer, and most low-end VGAs weren't really good at it.

Tweaking stuff like on-card wait states and overclocking the ISA bus itself did help in getting better framerates, however there was no comparison with a real 486 which had the benefit of a VESA local bus video card.

In terms of speed differences, it would be like comparing PCI (non-express) with AGP 8x or PCIe 16x. ISA: 16-bit, 8 MHz (overclockable to 13.333 MHz if you used CKLI/3 on a 40 MHz CPU), VESA: 32-bit and locked to the CPU speed, thus up to 50 MHz on a 486.

The lowest-end experience possible with Doom on the "IBM pee-cee compatible" would be a 386 SX/16, with an 8-bit ISA VGA card ;-)

Extra "awesome" if you somehow manage to find a non-IDE HD (preferably, a ST-506 interface 20 or 30 MB hard disk from the XT era).

Now, as far as the MS-DOS version goes, you simply can't run it with less than 4 MB of physical RAM (it's even hardcoded to check for that). Now, if somehow you manage to run doom.exe under some sort of pseudo-virtual memory environment on top of DOS which swaps RAM pages in and out from disk...that might make it possible to run with less than 4 MB, with the extra "bonus" of insane disk trashing ;-)

[Technician]

GoatLord said:

I suddenly remember playing "Rise of the Triad" at an electronics store around '94 or '95. I got motion sickness and actually had a goddamned seizure and fell the fuck over. My dad said my face was white and my lips were blue. Only time that's ever happened! But hey, I was like 10 or something. Maybe I was too young to handle psuedo-3D games. 'Cept I had already played "Doom" and "Wolfenstein 3D" by that point so I dunno.

No, I find anything built from the Wolf 3-D engine makes me feel ill after a short while. I really think it's the clunky movement that does my head in.

[Gez]

Technician said:

You can certainly understand why texture alignments weren't so perfect on old-school wads. I can't even fathom having to do it without 3D mode let alone waiting more than thiry seconds for the game to boot-up.

During development, they had Doom set up so that it read maps from a file rather than the iwad, just so they could idclev back to the level after editing it and it'd reload it from disc; without having to quit and restart the whole game.

But yeah, alignment was still a bitch. There was an interview with Michael Raymond-Judy (lead level designer in Heretic, who made or touched up all levels in the game) saying that the words "firstrow" and "firstcol" still made him shudder. :p

[_bruce_]

Slowest machine I ever tested it on was a 386DX40/8Meg ram.
It was the computer of my once ladyfriend's mom and I can honestly say I never saw Doom crawling like that.

[LogicDeLuxe]

I once tried Boom with 1 MB RAM out of curiosity. Of course, it was using the swap file a lot which slowed it down to a slideshow, but it basically was running.


I also tried Dark Forces on a friend's 4 MB machine (they were quite common back then) once. It actually did run when started on Windows 3.1, but it was very jerky now and then and the game sometimes freezed for several seconds due to swapping while the game physics was still running. The result was, that you where dead before you even realized that you were under attack.

[Optimus]

I think the first time I was playing doom I had a Cyrix 486 and maybe a slow graphics card (Isa maybe?) and I had to play in low detail and sometimes reduced window. I remember seeing doom in some classmates PC which also was a 486 but with a good graphics card (some Vesa local bus) and it was high res and smooth. Wow! So, I realized it must be the graphics card.

I have a 386dx at 40Mhz near me right now. Keeping it for retro stuff. From the whole bunch of old graphics cards I have salvaged, I have tested them all with benchmarks and kept the fastest one, of course it's an ISA card, Tseng Labs ET4000 capable of writting about 85fps to the VGA 320*200*8bpp the fastest way possible. Since Doom seems to be outputing byte after byte and not dword by dword (32bit at once like the benchmark) to the video ram then the most I could expect would not be over 20fps, though even the fastest 386 is not even enough for the engine calculations and rendering. It's still a crawl even after reducing the window. My 386 also has a Gravis Ultrasound btw, first time I have heard the classic doom music using this sound board. It sounds already better than the old adlib sound.

p.s. First day I realized the original doom was outputing one byte at a time instead of doing a 32bit copy was when I tried to replace just for fun the graphics card on a Pentium 3 with some slow ISA card. The old isa card I tried would do 40fps with the benchmarks at most, but you could clearly get no more than 10fps in doom benchmarks. So, since the CPU was already fast enough, I realized the only thing left that affects so badly must be the gfx card. For example, duke nukem 3d at the same stupid configuration was smooth like silk at around 40fps. I made quite a fuzz about it at the time. But of course I later realized, since doom was using ModeX where 4 pixels in a row are not in the same dword but you have to switch pages or something, it wouldn't be easy to copy 32bits at once from the buffer to the video memory. So, I left the case. Thing is, doom is mostly affected by the graphics card speed to write to vram (of course the CPU too, 386 is a no no). Have a Pentium with some slow gfx card and you are fucked :P

p.p.s. My horror was with trying to play Quake (and actually finishing it) in the same 486 Cyrix at 66Mhz. I was even playing without mouse at that period (used from the Doom era).

p.p.p.s. And I just remembered, my 386 is AMD, I have heard somewhere they can be overclocked at 80Mhz, unfortunatelly I have no experience with overclocking and I have to search for some info on the net about that. It would be cool to try doing this and run benchmarks, demos and doom of course.

[Maes]

Doom doesn't use mode x, only double buffering. Mode X is unsuitable for arbitrary-pixel rendering, being it a planar mode. It's much better suited for scrolling, tile-based rendering, bitblt ops (sprites and the such) and solid color fills, and Doom benefits from none of these rendering methods. That was also why fully texture-mapped games would not ever really be feasible/competitive on any of the Amigas chipsets or on EGA cards on the PC. Even at a CPU power parity, there would be too much wasted time doing chunky-to-planar conversions.

@Gez: the mode you described is called "reloadable files", you can still do that in source ports that didn't remove the feature by prepending lumps and .wad files in the -file option with a tilde "~".

Of course, it would still be useless under DOS, because you'd also need a multi-tasking environment to be able to switch between an editor and a running instance of Doom. Id had NeXT computers with a full UNIX-like OS, convenient GUI and even real-time same-screen visual debuggers, so that wasn't an issue.

For Pee-Cee users, assuming that the tilde/reloadable file trick was even known at the time (I bet it wasn't until the source code was released in 1997), it wouldn't have been technically possible to exploit it until Windows 95 became mainstream, and until everybody had 16 or more MB of RAM to play with. It might have been marginally possible to do before Windows 95 on OS/2 provided you had enough RAM and CPU horsepower to run two protected mode DOS applications at once in windowed mode (no idea if Doom would even run in such a state).

[printz]

GoatLord said:

It almost gives me a headache trying to fathom not being able to see what you're doing until you actually test the map.

You could still visualize the level in your head.

[Optimus]

Maes said:

Doom doesn't use mode x, only double buffering. Mode X is unsuitable for arbitrary-pixel rendering, being it a planar mode. It's much better suited for scrolling, tile-based rendering, bitblt ops (sprites and the such) and solid color fills, and Doom benefits from none of these rendering methods. That was also why fully texture-mapped games would not ever really be feasible/competitive on any of the Amigas chipsets or on EGA cards on the PC. Even at a CPU power parity, there would be too much wasted time doing chunky-to-planar conversions.

My mistake. I think it still used something similar to ModeX that gave a 320*200 resolution, just like regular 13h mode but with double buffering capability and it had also the advantages but still the disadvantages of planar mode. I think it was called Mode Y. I've got to check my source though.