stardot.org.uk

Yes, sorry, the file loading mechanism for Prince of Persia is a bit convoluted. It loads sectors directly from the disc in drive 0 so you can’t *COPY the files or run from a different drive I’m afraid. This was all because I needed ~50 catalogue entries but also wanted to fit everything on a single...

I am trying to understand "rupture" smooth vertical scrolling. I've seen some useful info on an Amstrad CPC464 forum, but would appreciate if anyone could check my understanding of a typical use case: - divide screen into 3 vertical regions: - 1 at top, small, static - 2 in middle, large, smooth (a...

The other thing to note is that very few vars need to be zero page. Obviously anything that’s using an indirected load/store through a pointer has to be in ZP and anything that’s in tight inner loops, like counters, would be advised. But if you’re only touching the var once per frame, or even less, ...

Welcome to the wonderful world of CRTC register abuse! It is a lot of fun. :D jsBeeb is by far and away the most accurate emulator when it comes to display timing but you should find both b2 and b-em are very good and sufficient for your experiments, unless you’re getting down to needing to update r...

Just completed this - still astounded that you got it to run on a BBC Master! I'd only played the first level before on an Atari ST (I think). It's amazing how many neat little touches there are across the 12 levels considering it's an 8 bit game. The Mode 2 graphics add a certain charm that I thin...

Hey all, I've recently started dabbling in some ARM development again, as a change from several years of 6502, targeting the 'classic era' Archimedes machines, so A310 through A5000, but mostly focused on A30x0 as a standard configuration. I thought I'd start a thread on setting up a modern developm...

Doh! I really wanted to come along to this one to support Jason and chip-in with some of my own BBC exploits. Alas it falls during the school half-term holidays so my wife has already booked us to be away for a long weekend. #-o I look forward to hearing how it goes and what the RISCOS folks make of...

I have an A3020 already so looking for an A3000 at this time.

Hello all, I’m interested in acquiring an A3000 for software development purposes. I am happy to pay a fair, but not excessive, price depending on configuration of RAM/HDD etc. Only requirement is that the machine is in full working order and the motherboard is demonstrably free of battery damage (c...

Elite typically did have anti-tampering CRC protection in a number of places.

I made a buildable disassembly of the BBC cassette version of Elite (probably the closest to the Electron version) which you can find on GitHub here: https://github.com/kieranhj/elite-beebasm

Maybe 2020 is the year of ‘next gen’...?

I found some time over the holidays to get my office set back up. I have managed to squeeze in 9 machines (not including the laptop) that can be used with only a modicum of cable shuffling. I’m on a bit of a ‘next gen’ trip for 2020 hence the Atari ST, Amiga and Archie. Of course it’ll all get destr...

I saw this mentioned on Twitter but didn’t have a link to the media for the talk itself, so thank you for posting that! Looking forward to watching it soon.

You’re just showing off now.

Any chance of an ssd now I’ve got my Elk set up with an SD64 plz?

Looking forward to what you come up with next and maybe a full length demo for NOVA2020...?

Thanks for doing a write up Sarah, this is really interesting. It’s been so long since I did any ARM, I naively assumed there would be no need for lots of unrolled code but clearly I’m completely wrong! I think I managed a 4x4 pixel rotozoomer but that was my limit BITD. There are a ton of awesome e...

IIRC many of the effects are done by changing the palette at the right moment. Can this be done on a FPGAtom, now that we have 64 colours and an eight MHz cpu core? This one has no fancy palette switching or CRTC tricks - at 2MHz there’s just enough time to move 64 3x3 pixel blocks independently. S...

:shock: :shock: Absolutely nuts! Such smooth animation. Brilliant! =D> =D> Btw, unlike the older version on the Bitshifters website, the latest version of JSBeeb enables sound on iOS: https://bbc.godbolt.org/?disc=https://bitshifters.github.io/content/bs-xmas-19.ssd&autoboot&model=Master :idea: Tha...

A festive greeting from Bitshifters for your BBC Micro!
https://bitshifters.github.io/posts/pro ... as-19.html

Amazing work! Love the high-res scanline look.

A great excuse for me to set my office back up after all the unplugging for ABUG! I’ll see if I can make a decent video capture from real hardware at some point too.

All but the earliest versions should work with higher PAGE - which one were you using Kieran? I regularly use ADFS and DFS with RT1.02 and that was fine :? Whichever one I got with my EEPROM. :) My B is still in a box after last ABUG but I’ll check when I set it all back up (hopefully tomorrow) and...

Thanks for the update! Any chance of a version that can cope with PAGE a bit > &1900 please? Several times I accidentally loaded two FS ROMs into my EEPROM so PAGE ended up ~&1B00. After that I get a ‘No Room’ error when trying to update ROM slots, which makes it a bit painful to correct my mistake.

So soon! Oh go on then, yes, please put me down for a table from Friday through Sunday. Thanks again for organising.

Great work Sarah! It was lovely to hear this on real hw at ABUG. Sounds amazing, like a real arcade machine and nothing like a Beeb!

Not very Acorn, I know, but does anyone have an Amiga 1200 they could bring along this weekend please? I have a new 8mb RAM upgrade for mine but it resolutely refuses to work. It would be great to determine whether the problems lies with the RAM board or my motherboard before I (continue) complainin...

Actually, it seems it didn't, at least not on the Model B. Oops, oh dear, that's definitely my bad, as they say. :oops: I'm slightly disappointed that no-one complained about it for the last two years. #-o Looks like 2 sectors reads is the way to go, at least for 'fast' devices (will need to test o...

I had a quick look at Teletext Bad Apple this afternoon (as I wanted to test the ICE-6502 in anger). On a Model B with the latest MMFS (1.44) it crashes consistently at 00:54 due to the ring buffer underflowing. Looking at why this might be, I noticed for "fast" devices the player is dynamically pa...

I still need to close the loop with Kieron on the Bad Apple / MMFS issues, so this may end up changing back again. Happy to do this at ABUG next weekend, a good opportunity to get to the bottom of it with the right people in the room! I also have a sneak peak of a new streaming demo so quite timely...

I’m sure there are some practical posts on here or maybe the old RetroSoftware programming forum. Otherwise check out the technical details on BeebWiki: http://beebwiki.mdfs.net/Address_translation#TTX_VDU

It’s been long established that with CRTC linear addressing mode, as used for MODE 7, the screen address is generally restricted to the top 1024 bytes of lower RAM, so &7C00 to &7FFF. However on Model B there is also a mapping to &3C00 which can be used for buffer swapping. Sadly this isn’t availabl...