Cover Art CD Label

Download
Source Code

A port of the open-source Doom code for the PC, as a demo in the early days of VM Labs/NUON. As such, it is highly unoptomized, and the framerate is low.

Don't bother trying any other wad files, as only the official shareware "doom1.wad" with a file size of 4196020 bytes will work.

This is the first open NUON game to exceed the 4.5MB limit, thanks to a new library that that allows games to read data from CD at runtime.

You can download a recompiled version for Aries 3 NUON DVD players here. It's just the NUON.CD file so you'll need to include the wad file from the original download. This version takes advantage of the faster Aries 3 processor found in the RCA and Samsung N504/N505 players to achieve a higher framerate.

Readme File:

Doom as an open-platform NUON game by Andreas Binner The NUON port of the shareware DOOM has been sitting around for quite a while now (almost 5 years). Since NUON is gone (at least in its original meaning) and at least a number of open-platform NUON players (incl. their loyal fans ;-) are around, I decided to take a shot in getting it to work. The main problem with open-platform games are that they have to fit in a single object file with a size limit of about 4.5MB - too small for DOOM, because the necessary doom1.wad file is already over 4MB! First I should suggest to read the original README.merlin from Eric. I contain a lot of interesting info about the port. However many things have changed since than already - and I don't just mean the name (Merlin vs. NUON). Mainly the introduction of the BIOS changed things like the MPE allocation: MPE 0: Audio code (libnise) MPE 1/2: Blitter MPE 3: Game C-code Here is what I added to the source: 1. CD reading The only way to get around the 4.5 MB limit is to have the wad file separate on the CD. That was leading to the first big problem: The N501 has no CD support in the BIOS, N505/N504 have CD reading support, but it's buggy. So I needed to write a library that allows a game to read from CD - which I did (libcdn50x.a), but that is the topic of a separate README. 2. Loading the wad file Now I was able to read the doom1.wad from CD directly and I took out Eric's pseudo ramdisk, but to my surprise it didn't work! The answer was simple: The CD reading library needs to take over MPE 1 to do its work. But MPE 1 is also used to run one of the software blitters! So as a quick hack I do just read the wad file once from CD into the old ramdisk - and it worked! The changes are mainly in: Makefile fileio.c filedata.s merl_video.c d_main.c There are two of compile time switches (LOADFROMDISK and N505) in the Makefile to control the build. LOADFROMDISK enables the loading of the doom1.wad from CD, by default using the BIOS. In addition, N505 switches to use the Samsung specific CD reading library. Two other switches (WAIT_FOR_BLIT and USE_MPE0) control the blitting process. Using MPE 0 as a third blitter increases the framerate but causes video glitches (I suspect timing and/or synchronization problems). The WAIT_FOR_BLIT seems to cause a deadlock. For both problems I had no time to investigate, so I left the two options disabled. 3. What else... Obviously it would be nice to get away from the ramdisk hack and just read wad files on the fly. This will require to share MPE 1 between the two users (blitter and cd loading) and switch back and forth between the two modes. Perhaps just using one blitter during loading or so. Andreas

Burning tips: Drag the NUON.CD and doom1.wad files into the root directory of an ISO9660 compliant CDR or CD/RW and close/finalize the disc. For assistance with burning NUON.CD files to CD-R, please read the guide.