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The Icon Bar: News and features: Rougol November talk - Mark Moxon

Rougol November talk - Mark Moxon

Posted by Mark Stephens on 07:13, 20/11/2022 |
This monthls Rougol meeting was live and in person (no Zoom, no recording and no post production tidying). However, we did manage to smuggle in a notebook and a concealed IPhone to give you the inside on proceeding....


Before the talk started, there was lots of discussion about Mark's time as a journalist at various RISC OS publications and his thoughts on the history of Acorn.
The actual talk itself was titled 'An Elite themed talk' and focussed on Mark's lockdown projects documenting and extend various versions of Elite and some other games.
Mark got his first BBC in 1983 and started playing elite in 1984
His brief bio is:-
1991 tech editor of Risc User
1993 editor of Acorn User
1995 travelled and worked for Acorn in New Zealand and Australia
1998 worked for Xara
1999 h2g2 website onwards
Since 2020 has been working again on Elite
2021 documented Aviator and Revs
2022 create Elite universe editor and teletext Elite. Also flicker free Elite on Commodore 64
Flicker free Elite is just better algorithm to erase one line at a time not ship. Code changes very small and only 8 bytes longer

Elite universe editor lets you edit the Elite universe including other ship characteristics and galaxy seeds

Teletext Elite is a work in progress. Uses sixels. Just hacked the graphics routines of Elite.

Future planned projects - Add Blue Danube music on BBC micro version, c64 editor universal editor document the sentinel , stunt car racer
Then we did an elite deep dive into the code for the rest of the talk.
Lockdown projects were to document source code of versions

This Code for elite is now on GitHub with deep dive articles
Annotated code around 1.6 meg in size
Atom variable names show which bits of code written on Atom.
66 spare bytes in code on BBC version.
Looked at custom screen mode used. 256 pixels per row made maths much simpler and one reason electron version slower as unable to copy
Galaxies created using 3 16 bit seed numbers using tribonacci series
Lots of details were explored in great depth and Mark explained how all the text was compressed and all the values extracted from the seed numbers.


This was a really interesting talk (especially if you were interested in Elite or programming). I hope Mark will come back soon and update us as it is still a work in progress.
The January ROUGOL meeting will be a hybrid talk with RISC OS Developments (half the speakers in the pub and half on Zoom) with Ben Finn rebooked for February.
As usual, details on the Rougol website.
  Rougol November talk - Mark Moxon
  stewartbrookes (02:06 22/11/2022)
  Stoppers (20:52 22/11/2022)
  helpful (04:15 24/11/2022)
    markee174 (08:24 24/11/2022)
Stewart Brookes Message #125363, posted by stewartbrookes at 02:06, 22/11/2022
Posts: 5
Thanks for the detailed report, Mark. It almost feels as if I was there!

For a preview of the amazing feat that is Teletext Elite, see the clip here:
  ^[ Log in to reply ]
Simon Willcocks Message #125364, posted by Stoppers at 20:52, 22/11/2022, in reply to message #125363
Posts: 302
It looks remarkably playable, for being 80x96 resolution! It makes the original look positively high resolution.

I remember duplicating the 256x256 resolution and hidden line removal (requiring objects to be convex) in a custom mode, back in the 1980s. I don't think I got the mode switch near the bottom to work (Revs used a similar trick).

I'm seriously in awe of what they managed to achieve in that game.
  ^[ Log in to reply ]
Bryan Hogan Message #125366, posted by helpful at 04:15, 24/11/2022, in reply to message #125363
Posts: 243
Thanks for the excellent write up Mark. And good to see you again Stewart after far too long a gap!

Note that the thumbnail picture of the teletext version is a duplicate of the one above. Clicking on it gives the correct picture.
  ^[ Log in to reply ]
Mark Stephens Message #125367, posted by markee174 at 08:24, 24/11/2022, in reply to message #125366
Does all the
work around here

Posts: 118
Fixed and many thanks for organising a great meeting.
  ^[ Log in to reply ]

The Icon Bar: News and features: Rougol November talk - Mark Moxon