Search found 1035 matches

by Rich Talbot-Watkins
Fri Sep 22, 2017 3:43 pm
Forum: hardware
Topic: NuLA demos
Replies: 116
Views: 3299

Re: NuLA demos

sbadger wrote:here's a taster...

Looks lovely! This is what the Video NuLA was made for!
by Rich Talbot-Watkins
Fri Sep 22, 2017 8:50 am
Forum: hardware
Topic: NuLA demos
Replies: 116
Views: 3299

Re: NuLA demos

sbadger wrote:Yeah, without giving too much away i'm working on a native 16 colour version of Galaforce as we speak....

I think you just gave everything away! :lol:
by Rich Talbot-Watkins
Thu Sep 21, 2017 12:38 pm
Forum: hardware
Topic: Origins of the BBC keyboard layout
Replies: 9
Views: 348

Re: Origins of the BBC keyboard layout

Just to drift OT a little, my PC keyboard is a Corsair K70 mechanical keyboard, with Cherry Blue key switches, and it's absolutely lovely to type on. For me, proper keyswitches are a must now, and the noisier the better! They bring back that Beeb retro feel, and they somehow make typing 'fun'. On th...
by Rich Talbot-Watkins
Wed Sep 20, 2017 8:36 am
Forum: hardware
Topic: Origins of the BBC keyboard layout
Replies: 9
Views: 348

Re: Origins of the BBC keyboard layout

The Mimi 802 made by British Micro also has a keyboard very reminiscent of the Beeb's: http://i.ebayimg.com/images/g/WwIAAOSwSclXLl5U/s-l1600.jpg Very slightly different layout, but Shift Lock is there, as well as a big zero glyph which takes up the whole of the key! They date from 1981, around the ...
by Rich Talbot-Watkins
Sun Sep 10, 2017 11:11 am
Forum: projects
Topic: Cowgol achieves first light!
Replies: 20
Views: 721

Re: Cowgol achieves first light!

How are you determining the return type of multiplies? The natural result length is the sum of the operand lengths, so you'd naturally expect a uint8*uint8 to yield a uint16. If you're currently applying the same rules as an add, i.e. both operands need to be the same size as the result, you're maki...
by Rich Talbot-Watkins
Fri Sep 08, 2017 5:09 pm
Forum: projects
Topic: Starting a Prince of Persia port...
Replies: 64
Views: 3479

Re: Starting a Prince of Persia port...

Hmm yeah, the graphics data is pretty bulky! From my best understanding, the scenery tiles are an awkward size on the Apple (28x63), and are rendered in a complicated way. In particular, what intrigues me is the way the floors are rendered: http://3.bp.blogspot.com/-2K2mV0_zH0A/TqUGSEXWNFI/AAAAAAAAA...
by Rich Talbot-Watkins
Fri Sep 08, 2017 1:03 pm
Forum: projects
Topic: Starting a Prince of Persia port...
Replies: 64
Views: 3479

Re: Starting a Prince of Persia port...

My gut instinct on this is that the only bit which you can probably truly 'port' is the game/animation logic, basically all the high-level stuff. The graphics routines are going to need to get a total rewrite to conform more with the Beeb hardware. My take on it would be to bite the bullet and go to...
by Rich Talbot-Watkins
Mon Sep 04, 2017 9:25 pm
Forum: hardware
Topic: NuLA demos
Replies: 116
Views: 3299

Re: NuLA demos

Wow, crikey! :shock: That looks more Amiga than an Amiga! Fantastic work Rob!

Isn't there some way to upload a 50Hz video to YouTube (which can then be played at the right frame rate)?
by Rich Talbot-Watkins
Sat Sep 02, 2017 9:09 pm
Forum: projects
Topic: Cowgol achieves first light!
Replies: 20
Views: 721

Re: Cowgol achieves first light!

That all sounds pretty sensible and predictable. In a platform like 6502, telling the compiler as much as you can is normally a good thing. If pointer types exist, I think there's definitely a case for being able to index from them with both uint8 and uint16, if anything just because a uint8 index t...
by Rich Talbot-Watkins
Sat Sep 02, 2017 8:40 am
Forum: projects
Topic: Cowgol achieves first light!
Replies: 20
Views: 721

Re: Cowgol achieves first light!

My suggestion was that operators return a result the same length as their longest operand. If you can then specify a length for literals, you can specify precisely what you mean. e.g. suppose literals default to 8-bit values. index + 1; # uint8 + uint8 = uint8 index + 1L; # uint8 + uint16 = uint16 i...
by Rich Talbot-Watkins
Fri Sep 01, 2017 9:35 pm
Forum: programming
Topic: Aseembler problems with #< and >#
Replies: 9
Views: 200

Re: Aseembler problems with #< and >#

Hmmm having looked at it a bit more closely, I understand the problem - there should be no difference between the first two snippets, but they give different results. Which platform are you running on out of interest? Not an old big-endian PowerPC Mac? (Edit: not that I can imagine why it ought to m...
by Rich Talbot-Watkins
Fri Sep 01, 2017 9:20 pm
Forum: programming
Topic: Aseembler problems with #< and >#
Replies: 9
Views: 200

Re: Aseembler problems with #< and >#

Which version of BeebAsm are you on? From my release notes: 1.03 Bugfix: Corrected the unary < and > operators to correspond to HI and LO as appropriate. I never use < and > as they always confused the hell out of me (precisely why I created HI and LO), and evidenced by the fact that I got them the ...
by Rich Talbot-Watkins
Fri Sep 01, 2017 9:10 pm
Forum: projects
Topic: Cowgol achieves first light!
Replies: 20
Views: 721

Re: Cowgol achieves first light!

Probably needs some way of specifying the type of literals. Then you can define that addition always yields a result of the longest type (or whatever rule suits best). Are arrays always fixed size (so they can use indexed addressing as a shortcut in the case of them being <256), or are they intercha...
by Rich Talbot-Watkins
Fri Sep 01, 2017 1:01 pm
Forum: software: classic games
Topic: Authors of one published game
Replies: 7
Views: 192

Re: Authors of one published game

Yep, Joust was eventually released as Skirmish. And Bolo was never released at all!
by Rich Talbot-Watkins
Fri Sep 01, 2017 10:30 am
Forum: software: classic games
Topic: Authors of one published game
Replies: 7
Views: 192

Re: Authors of one published game

Incidentally, Stuart Cheshire's CV includes the following:
Magazine Work. Have written for many computing magazines, including ‘Computer Fraud and Security’, ‘Beebug’, ‘A&B Computing’ and ‘The Micro User’, ‘Input’.

Would be interesting to see any of his articles, if anyone knows where they are.
by Rich Talbot-Watkins
Fri Sep 01, 2017 10:16 am
Forum: software: classic games
Topic: Authors of one published game
Replies: 7
Views: 192

Re: Authors of one published game

http://everygamegoing.com/landing/authors/8655/Michael_St_Aubyn.html Every Game Going has him down as the author of Acornsoft Volcano, as well as Pantry Antics, and a Spectrum title. Looks like he just gave up on games after that! I was always curious about the mysterious Delos D. Harriman, who did ...
by Rich Talbot-Watkins
Thu Aug 31, 2017 11:09 am
Forum: software: other
Topic: Another C compiler?
Replies: 6
Views: 327

Re: Another C compiler?

(I also found this unrelated but interesting story of building a C compiler over 40 days ) Great link Ed! Always fancied trying to write a compiler for a toy language of my own, just for the challenge, but have never been quite sure where to even start. I'm not sure whether reading the Dragon Book ...
by Rich Talbot-Watkins
Tue Aug 29, 2017 5:05 pm
Forum: programming
Topic: Procedural greneration
Replies: 3
Views: 166

Re: Procedural greneration

And there are some more random number generators on this page if you need a larger seed size, or you're just finding your results to be not random enough!

http://codebase64.org/doku.php?id=base:6502_6510_maths
by Rich Talbot-Watkins
Mon Aug 28, 2017 7:20 pm
Forum: development tools
Topic: beebasm putbasic problem
Replies: 9
Views: 278

Re: beebasm putbasic problem

jsbeeb's BASIC tokeniser actually uses the BASIC 4 ROM code to tokenise lines! As in: it creates a fake Beeb, puts the ASCII string into the right place in memory, sets up the necessary zero page, and then emulates the ROM call until it exits. https://github.com/mattgodbolt/jsbeeb/blob/master/basic-...
by Rich Talbot-Watkins
Mon Aug 28, 2017 2:45 pm
Forum: software: classic games
Topic: Exile
Replies: 19
Views: 1608

Re: Exile

You're quite sure then there are no remaining subtle changes in the cracked game? It's almost a pity, as there might have been more to learn... Can't be 100% sure, though we have an annotated disassembly and can see where the novella protection code used to be (and how it was removed). I would rema...
by Rich Talbot-Watkins
Mon Aug 28, 2017 12:18 pm
Forum: software: classic games
Topic: Exile
Replies: 19
Views: 1608

Re: Exile

The copy protection on the Beeb version was still pretty nasty. There were two parts to this: the disc protection and the novella password request. The disc protection was pretty unusual: the disc had its own encrypted catalog sector, and implemented custom file operations to load them (by redirecti...
by Rich Talbot-Watkins
Sun Aug 27, 2017 8:21 am
Forum: software: classic games
Topic: Exile
Replies: 19
Views: 1608

Re: Exile

The story's not true, at least not on the Acorn versions. The worst effect of hacking out the copy protection code (badly) is that it would hang after two minutes, like the demo mode.
by Rich Talbot-Watkins
Thu Aug 24, 2017 7:54 am
Forum: software: other
Topic: not in the books : lda#&80:sta &fe30
Replies: 6
Views: 397

Re: not in the books : lda#&80:sta &fe30

no more :) but it do nothing for the normal beeb b ? It could likely crash a BBC B, as the code is reading from &FE30, which is a write-only register on a regular Beeb. So when X is written back to &FE30 at the end, it'll be writing an undefined value. On the Master, &FE30 is read/write.
by Rich Talbot-Watkins
Wed Aug 23, 2017 2:17 pm
Forum: software: other
Topic: not in the books : lda#&80:sta &fe30
Replies: 6
Views: 397

Re: not in the books : lda#&80:sta &fe30

This is redefining the character set on the Master. Only ASCII codes 64 to 95, curiously.
by Rich Talbot-Watkins
Tue Aug 22, 2017 10:20 am
Forum: emulators
Topic: directx 9 error with beebem ?
Replies: 8
Views: 238

Re: directx 9 error with beebem ?

:lol:

d3d9 = Direct 3D 9, i.e. the 3D video drivers for DirectX 9.

You can go to Windows -> Run, and type dxdiag to get diagnostics on your DirectX drivers and hardware.
by Rich Talbot-Watkins
Tue Aug 22, 2017 9:26 am
Forum: software: classic games
Topic: "Unfixable bug" in BBC B Elite
Replies: 32
Views: 1274

Re: "Unfixable bug" in BBC B Elite

I guess Elite doesn't use it for planet rendering because planets also have ellipse arcs on their longitude, which can't be calculated with the Minsky recurrence. Here's a BBC BASIC program to draw a Minsky circle, using floating point. http://i68.tinypic.com/af7ss9.png With integers, it looks decid...
by Rich Talbot-Watkins
Mon Aug 21, 2017 11:07 am
Forum: software: classic games
Topic: "Unfixable bug" in BBC B Elite
Replies: 32
Views: 1274

Re: "Unfixable bug" in BBC B Elite

I was trying to understand the maths behind this a bit more. Starting with the two equations: x' = x - ey y' = y + ex' and expanding out, we get: x' = x - ey y' = y + e(x - ey) = y + ex - e^2 y = y(1 - e^2) + ex In matrix form this can be written: [ x' ] = [ 1 -e ] [ x ] [ y' ] [ e 1-e^2 ] [ y ] ......
by Rich Talbot-Watkins
Mon Aug 21, 2017 8:17 am
Forum: software: classic games
Topic: "Unfixable bug" in BBC B Elite
Replies: 32
Views: 1274

Re: "Unfixable bug" in BBC B Elite

That code is actually making use of a peculiar thing called the Minsky Recurrence. Note these lines: y = y - alpha * x; x = x + alpha * y; The calculation for x is actually making use of the new value for y, not the original one. This is completely stable, and repeats periodically, but doesn't rotat...
by Rich Talbot-Watkins
Fri Aug 18, 2017 9:49 am
Forum: software: classic games
Topic: "Unfixable bug" in BBC B Elite
Replies: 32
Views: 1274

Re: "Unfixable bug" in BBC B Elite

..but will he remember? And don't forget, he didn't write all of it. Maybe we need to ask Ian Bell, too. Matt Godbolt has had friendly contact with Ian Bell in the past (asking for permission to host Elite as the default loaded jsbeeb game), so maybe he can ask. I think Bell was responsible for rat...
by Rich Talbot-Watkins
Fri Aug 18, 2017 9:46 am
Forum: software: classic games
Topic: "Unfixable bug" in BBC B Elite
Replies: 32
Views: 1274

Re: "Unfixable bug" in BBC B Elite

Aha, why "probably not quite as well"? I see no reason to asume that... Just judging by what you can outwardly observe. Elite runs at a better frame rate, with more complicated ship designs. Star Clash's geometry is rather more simplistic, and it really starts to chug when there's a bit o...

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