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.