Memofest 2016

Memofest 2016 was held on 29th October at David Stevensons place in Aberdeen.

Attendees were myself, Claus, Mark, Paul, Martin, Bill and Dave. Jim attended virtually via Skype, and is visible on the iPad. Dave's wife Nicola and Paul's wife Julie facilitated the event :-

Daves places is basically a Memotech lab :-

I showed my REMEMOTECH r2, which has the numeric accelerator from REMEMOrizer, thus allowing it to do the MAND Mandlebrot speed test in 82s, 6x faster than ever done before. MTXPlus+ with Z180 does however still retain the crown for general purpose computing. Grrr...

Bill showed his 80 column card, which is based on £10 of chips, including a Propeller. This sports 64 colours and with the creation of a CRT driver could be used for CP/M :-

Lunch was served, appreciated by all.

Dave, Martin and Tony have all been working on MTXPlus+. We saw it running, including with 6502 add-on, BBC BASIC and shared memory bus between them :-

Paul showed his games toolbox he has been working on. Nice routines to display slideshows and play chiptune music :-

Paul also brought a video daughter card to test, which seemed ok.

The cake was amazing, but could not have shown a real Memotech circuit board, as no yellow wire was visible :-

Bill showed off his changes to MEMU, allowing it to load games from .wav files. I really need to look at picking up some of his changes :-

I unveiled HEXTRAIN. In this game you get to be a train driver, picking up passengers and delivering them to their destination stations. The game has 192x128, 15 colour, 16 fps 3D solid animated graphics, which is of course, completely impossible. There were numerous things that all contributed to this, including :-

• The existence of fast disk, ie: Silicon Disc, SD Card or Compact Flash, which the game relies upon in order to work
• The NARA prototype, showing that a limited kind of video playback is possible
• Changes to the MR Modular Renderer to fix off-by-one-pixel errors in polygon rendering
• Changes to MEMU to add support huge Silicon Discs
• A change to the BE Binary Editor to support the NoICE symbol table, as generated by SDCC

No photo here, but go to the HEXTRAIN page for the gory details. We didn't really get much time to play it, which is a shame.

I also showed bits of the code, the 3D train-set explorer, the compiler, the files that are generated and how to debug it.

HEXTRAIN runs on MEMU, REMEMOrizer, REMEMOTECH, and CFX, and Dave was keen to try it on MTXPlus+, and anticipating this, I had brought a Compact Flash card. However, the result wasn't pretty :-

HEXTRAIN is probably the most aggressively timed game thus far for any Z80 and VDP based system.

Jim emailed in a PotHole Pete version for Windows. Unfortunately the tablet used for Skyping lost power in the afternoon.

Claus designed a Memofest T-Shirt and he showed a port of the "C-So" platform game, and of Moon Patrol (here shown on BlueMSX emulator) :-

VDP timing is also a challenge when porting games, as MEMU allows programs to go faster than a real VDP, with no issues. Claus petitioned for MEMU changes to help with this.

There was mexican food for tea, and beer.

Mark helped fix Daves video wall PC, which has some kind of 12V regulator (and possibly capacitor) issue resulting in overheating and loss of picture. Judicious use of freeze-spray proved the point, allowing us to control Daves wall. I suspect the wall hardware pre-dates support for "colour-washes", as they didn't seem to work. However the basic effects appear to work for most of the framestore cards. It was strangely satisfying to see a wall working again :-

A great day with lots of interesting exhibits and activities, eclipsed only by Scottish hospitality.

Memofest 2017 was held at Martins place in Hastings.