Computer Workshops

Status: Preview, Findability: 3/5

Also known as: Aptitude

Nether is a game that I can remember from the days of Commodore Scene, being touted as a Doom clone. Eventually when I saw a preview, there wasn’t much to see and I then completely forgot about it.

The game’s development had however been continuing way into 2004 – where a new engine was developed called Nether G-II. It was lacking sprites though, but apparently was a lot more sophisticated compared to the old blocky and slow engine. Although we sound critical, the game was one of the first engines to have light sourcing included – it just was character block blocky and slow.

We assume that the game was to be a straight Doom clone, as this is how the game was sold on their website (which we’ve grabbed an archived copy for you to see – see Creator Speaks).

What happened to the game? There had been no updates since around 2004, so we assume that the project is now officially dead. However, the game resurfaced again in 2012 in the form of “Aptitude”.

Instead of being a Doom style game, Cameron had reworked the title to become more of a puzzler – inspired by Portal it seems. A special free three level pretest pack was released (see downloads) and the full edition was due for release in Winter 2013.

Sadly it didn’t make that release date, and the game is still yet to be finished. The page for Aptitude is still online currently at

We hope that it is completed some day, especially as we are seeing so many new C64 games finished these days and released. Cameron may get the final urge to finish the title once and for all.

Contributions: Kevin Tilley

Supporting content

Available downloads

Creator speaks

From Computer Workshops’ Official Nether Preview Page…

3-D, texturemapping and lightsourcing in real time on a stock 64.
Play DOOM on your Commodore 64, and you don’t need a SuperCPU to do it.
Last modify September 2009. You’re visitor 15926.

See some screenshots!
Check out and download the alpha version! (warning: this uses the old webpages, since we won’t be updating them)

Next Nether News

Here’s the story so far, for those of you who haven’t been following — for shame!: We released Nether G-I (which you can download from here) to an eager public as an alpha test a while back. It was generally well received, but it could have been made a lot better. So, believing that the best product is the best product (foolish, eh? :-), we’re developing a new, more sophisticated version of Nether called Generation II, or Nether G-II for short.
As of 11 December 2004: The current sprite-less Nether G-II is finished … but Nether itself needs sprites for gameplay. Fortunately, not all games do, and there’s going to be a title in particular that will use the 3-D engine sans sprites, right now. Tune in for more info.

As of 16 October 2002: Here’s what’s happened so far. Thanks to new unrolling optimizations, plus a special 1-byte lighting cache to speed up sector texture lighting computation, we now have an engine that has achieved 10fps (raw render time) reliably with all lighting and enhanced texture effects — on the stock C64! (It’s potentially enormously faster on the SCPU but this game is targeted for the stock system, just as we’ve always said.)
This engine renders 12-stage turns (no more 90-degree jumps) as well, for smoother motion, and preserves the entire G-I lighting model.
Look for us at VCF 5.0 October 26 — we’ll be showing a tech demo of Nether G2 at the Micro-Portables exhibit hosted by programmer Cameron Kaiser! Visit the Vintage Computer Festival web site at

As of 22 March 2002: Much has happened since our last update. All the map bugs, including the front tile lighting problem, have been repaired. For the sake of expediency, the old blackout hack for looking around corners has been implemented (it was also in G-I). The spherical aberrations unmasked by the improved fidelity TIM have been recomputed and smoothed out to an acceptable level, and a few other detected glitches in the lookup tables for views and skews have been tweaked.

Optimization is nearly complete. Alas, it seems we can’t get much faster than 9fps or so; average speed is around 7, which is still a considerable gain over G-I. The TIM draw-a-pixel loop has been special-cased and unrolled into very long simple sequences for drawing particular texel strips of varying height. While this generates a considerably larger object file (ballooning to 11K from 5K) it has shaved over four jiffies/frame off render time, bringing the speed up noticibly. If we can squeeze one more jiffy out of the runtime, we’re probably in good shape.

After that, strafe support will be added, and then sprites.

As of 27 October 2001: Work continues. A major breakthrough last evening; the jitter in the texture mapper has now been cleaned up with a new (although slower) patch to the TIM library. This slows down rendering somewhat but the result is a very, very clean mapping with no jitter. Alas, the improved TIM is now unmasking previously imperceptible spherical aberrations in the lookup tables used for mapping the environment, which means these will have to be regenerated. Too accurate for its own good! But we’re not too angry. :-)

There are also still the map bugs mentioned previously, but these are now top priority. Once repaired, the lookup tables will be tweaked and then the optimization will begin. As previously mentioned, target engine speed is 10-15fps.

Update history

15/12/21 – Added details about Aptitude, the game that Nether formed into.

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