Doom on a 4mb A3020?

[trixster]

Hello,

Is it possible to run Doom on a 4mb A3020? I assume it is but it runs out of memory on my system. I'm running Uniboot2 with an 8bit etherlan podule, so after boot I've only got about 2.5mb free.

Is there anything I can do to run Doom? Is it possible to use a boot disk (like an old pc) or some such method to maximise the available memory?

[flibble]

Hold down shift on startup to prevent the uniboot from booting. It'll just go to the desktop without loading all the bits.

I did manage to run DIY doom [1] on my 4MB A4, but it's not at all fast on an ARM3, I suspect it'll be pretty terrible on an ARM250.

[1] There were two doom versions for RISC OS, DIY doom that you compiled up from the open source release, and a commercial release from R-Comp, which do you have?

[trixster]

I've got the rcomp doom+ version

[flibble]

I don't think that will ever work on a RISC OS 3.1 machine.

[SarahWalker]

Doom+ will work, but it's slow on anything less than an ARM3. It's pretty slow on an ARM3 to be honest (386 speeds) but it is at least playable.

[trixster]

Yeah, there's a vid on YouTube with it running on a 4mb a4000. I'm just interested in seeing it running from a technical PoV, not to play it seriously. I find it amazing that it will even run on a 12mhz machine - my 80mhz Amiga with 68060 needs a lot of grunt to play it as it is. Looking at vids of the BaDMooN Atari falcon version of Doom (16mhz 68030 with 14mb and the DSP) made me wonder what the Arc could achieve. The falcon version is quite incredible (and that's even before you start looking at the quake 2 and quake 3 tech demos they've made!).

[derek]

Hi,

The C source code to DOOM is on Github:

https://github.com/id-Software/DOOM

Could this not be ported over

[daveejhitchins]

Hi,

The C source code to DOOM is on Github:

https://github.com/id-Software/DOOM

Could this not be ported over

Convert it to 6502 assembler - it'll then run on the electron in a ROM

Dave H

[SarahWalker]

typical playground nonsense

I was at a retro event hosted at ARM a little while ago, where my R260 ended up next to an Amiga 1200 with, I think, an 030 board. Both were running Doom at one point, and interestingly, the reaction from most onlookers was that the Amiga version was better. The Acorn was running it a little quicker (though still at around 12 fps, in low detail mode), but the VIDC colour palette was so bad that it just put everyone off. The game was almost running in greyscale.

[SarahWalker]

The C source code to DOOM is on Github:

https://github.com/id-Software/DOOM

Could this not be ported over

Both the commercial and free Acorn ports of Doom are ports of that code.

[derek]

Hi,

The C source code to DOOM is on Github:

https://github.com/id-Software/DOOM

Could this not be ported over

Convert it to 6502 assembler - it'll then run on the electron in a ROM

Dave H

Since the Doom source is written in C, a good C compiler would convert it to 6502 code.

I am not about Acorn C compilers, is there any ANSI C compiler available, without any restrictions.

[derek]

The C source code to DOOM is on Github:

https://github.com/id-Software/DOOM

Could this not be ported over

Both the commercial and free Acorn ports of Doom are ports of that code.

Just a matter of porting it. Not mean feat... as the Amiga version needs a fast CPU, maybe out of reach for 6502. However, RISC maybe the answer.

[trixster]

I'm impressed with what the arc can achieve - the frame rate on the YouTube video I mentioned is better than I expected, and my point was that an Amiga needs an 80mhz 060 to run at higher than 20fps at 320x265, and the falcon uses the DSP and good coding in order to get around the slow 16mhz 030 cpu limitation. The versions of doom I've seen runnig on an 030 Amiga have been pretty crap, in my opinion.

[SarahWalker]

20 fps? To be honest that's faster than you'll get out of any Acorn system slower than a StrongARM.

[SarahWalker]

I was curious to see if my previous statement was true, so I ran Doom+ on a Mico (ARM7500FE @ 56 MHz with EDO memory), which is supposed to be a little faster than a RiscPC 700. Timedemo demo1 gave a not hugely impressive 13.67 fps, which is a bit worse that I thought it would be - that's about the same speed as a 486/33. For comparison, my R260 (ARM3 @ 26 MHz) got 9.28 fps, and an A4000 (ARM250 @ 12 MHz) gets 3.24. I guess Doom just doesn't like the ARM7-and-earlier architecture! Slow LDR and STR instructions are a likely culprit - Doom does a lot of single load/stores when texture mapping.

[trixster]

It looks like the version I have is the Jeffrey Doggett Doom For Arm version 1.1, not the RComp Doom+ version.

Upon running it actually says it needs 5000k to launch, and the readme talks about 32bit Arms, so I guess this precludes the A3020/A3000.

The version on youtube must be Doom+.