Search found 156 matches

by jregel
Thu Dec 05, 2019 6:36 pm
Forum: hardware
Topic: A blitter for the beeb?
Replies: 118
Views: 11521

Re: A blitter for the beeb?

Would there be interest in me doing a BeebEm version that contained the Blitter - this would probably be a fork and unlikely to contain all the extra processors initially? If there's interest I'll start on it now - I'm about to start on a big refactor of the vhdl which is a bit of a mess and will I...
by jregel
Tue Dec 03, 2019 9:32 pm
Forum: projects
Topic: BeebEm Alpha Fork with SID and PAULA sound
Replies: 12
Views: 316

Re: BeebEm Alpha Fork with SID and PAULA sound

Wow - very impressive!

I created a quick disc containing some of my favourite mods from back in the day, written by Dr Awesome.
by jregel
Mon Dec 02, 2019 11:37 pm
Forum: projects
Topic: BeebEm Alpha Fork with SID and PAULA sound
Replies: 12
Views: 316

Re: BeebEm Alpha Fork with SID and PAULA sound

dominicbeesley wrote:
Mon Dec 02, 2019 7:50 pm
Is there genuinely no interest or have I done something daft? So far it looks like nobody has tried the download or have I made a balls of publishing it on GitHub?
I will be, just working today and had a meeting this evening, so no Beeb time.
by jregel
Fri Nov 29, 2019 4:46 pm
Forum: hardware
Topic: A blitter for the beeb?
Replies: 118
Views: 11521

Re: A blitter for the beeb?

The Blitter doesn't do anything with the actual video generation so new modes aren't really possible - though with shadowing in place larger screen modes are possible. Yep, understood. Any "new modes" would ultimately have the output characteristics and limitations of existing screen modes. I was t...
by jregel
Fri Nov 29, 2019 10:24 am
Forum: hardware
Topic: A blitter for the beeb?
Replies: 118
Views: 11521

Re: A blitter for the beeb?

Thanks Dominic My original thought process was basically that if a 20K Mode 2 screen could be comprised of 2x10K Mode 5 screens, you could have an interesting and useful seven colour mode which provides a four colour background layer and a three colour foreground layer (plus transparent). Or a Mode ...
by jregel
Thu Nov 28, 2019 2:59 pm
Forum: hardware
Topic: A blitter for the beeb?
Replies: 118
Views: 11521

Re: A blitter for the beeb?

Thanks Dominic - really interesting information. As a Master owner, I’m seeing this through the lens of how the Blitter board will work on the Master, and I don’t know quite so much about the B and Electron (despite owning one when I was growing up). Re: OSRAM-like functionality, this could be inter...
by jregel
Wed Nov 20, 2019 11:01 pm
Forum: software
Topic: Karma - The Flight Trainer
Replies: 23
Views: 1141

Re: Karma - The Flight Trainer

AcornKarma wrote:
Mon Nov 18, 2019 10:01 pm
I will be around now and again in this forum. Ask questions if you like. I was thinking today about a series of posts that go into greater depth, we shall see.

Ian
Hi Ian

I'd definitely be interested in a series of posts that digs into the details of how you did Karma.
by jregel
Sun Nov 17, 2019 9:50 pm
Forum: introduce yourself
Topic: Hello, I am Ian, in Oslo
Replies: 15
Views: 364

Re: Hello, I am Ian, in Oslo

Welcome Ian.

Yes, at least one of us (and probably lots more!) have put two and two together.

Hope you get your hard disk safely backed up and that you've not lost anything important and unique...
by jregel
Sun Nov 17, 2019 5:16 pm
Forum: hardware
Topic: A blitter for the beeb?
Replies: 118
Views: 11521

Re: A blitter for the beeb?

Hope your move goes well! More questions, you say? I have more questions... :-) I'm trying to get a deeper understanding of the memory map for the 6502 when the Blitter board is installed. Is the following broadly right? Presume the top 16K (&C000-&FFFF) still maps to the MOS ROM? I did stumble on a...
by jregel
Fri Nov 15, 2019 7:04 pm
Forum: hardware
Topic: A blitter for the beeb?
Replies: 118
Views: 11521

Re: A blitter for the beeb?

Thanks for the big update (a couple of posts back) and great news regarding the Master! Just out of interest, how are you planning on mapping the 2MB RAM? You mention two sets of sideways RAM/ROM, but how is that configured and what ROM slots would they map to on a machine like the Master which alre...
by jregel
Thu Nov 14, 2019 11:33 am
Forum: emulators
Topic: Arculator v2.0 released!
Replies: 23
Views: 1764

Re: Arculator v2.0 released!

A great release, thanks.

The previous version didn't go into fullscreen mode properly in Windows, but 2.0 does without any problems.
by jregel
Fri Nov 08, 2019 5:03 pm
Forum: emulators
Topic: Best emulator for playing Archimedes games?
Replies: 4
Views: 512

Re: Best emulator for playing Archimedes games?

Thanks everyone. I followed Sirbod's notes and have now gotten Karma working in Arculator. Rather strangely, I was unable to copy eight files in the !Karma.Q directory, when using the ArculFS interface. When I renamed the files in Windows to not have the ",ffd" filename extension, they copied fine, ...
by jregel
Wed Nov 06, 2019 9:07 am
Forum: hardware
Topic: Best display for a BBC?
Replies: 12
Views: 738

Re: Best display for a BBC?

@jregel - is this the converter you have? https://www.amazon.co.uk/Flylink-Converter-Upscaler-Coaxial-Consoles/dp/B00W9DJMNC/ref=sr_1_19?crid=3R1QE5RVGMVP&keywords=scart+to+hdmi+converter&qid=1572986821&sprefix=scart+to+%2Caps%2C134&sr=8-19 Its by Flylink (I've never heard of them). There seems to ...
by jregel
Fri Nov 01, 2019 11:17 pm
Forum: general
Topic: Remarkable videos recently posted on Youtube
Replies: 288
Views: 34459

Re: Remarkable videos recently posted on Youtube

Anyone want to play Sonic the Hedgehog running on the Amstrad CPC+...

http://www.indieretronews.com/2019/11/s ... othly.html

Looks very nice.
by jregel
Fri Nov 01, 2019 1:57 pm
Forum: emulators
Topic: Best emulator for playing Archimedes games?
Replies: 4
Views: 512

Best emulator for playing Archimedes games?

So I fancy having a go at Karma: The Flight Trainer, but not found a decent way to play it. I have access to PC, Mac, Linux, and RISC OS (on Pi), so possibly have lots(?) of options in terms of emulation. I have Karma in an ISO file, so assume I either need to copy the files off (while preserving th...
by jregel
Sat Oct 26, 2019 12:08 pm
Forum: hardware
Topic: Best display for a BBC?
Replies: 12
Views: 738

Re: Best display for a BBC?

I already had a SCART to HDMI scaler that I was using for playing retro consoles on our living room TV, so thought I'd try that, combined with an HDMI to VGA converter, and an old LCD VGA monitor. The results are surprisingly crisp, certainly better than the Sony TV at high resolution modes. IMG_412...
by jregel
Tue Oct 22, 2019 12:02 pm
Forum: software
Topic: Karma - The Flight Trainer
Replies: 23
Views: 1141

Re: Karma - The Flight Trainer

Anyone interested in playing Karma - The Flight Trainer, it is available here: https://archive.org/details/cdrom-riscos-au-cd10 I've managed to get it running in RPCEmu, but it's way too sensitive and fast to play, and I've not yet found a way to slow it down. Perhaps I need to play with another emu...
by jregel
Mon Oct 21, 2019 4:15 pm
Forum: software
Topic: Karma - The Flight Trainer
Replies: 23
Views: 1141

Re: Karma - The Flight Trainer

The interview has gone public: https://www.youtube.com/watch?v=KPYkHo0cNhk

Was a very interesting listen.
by jregel
Wed Oct 16, 2019 10:22 pm
Forum: software
Topic: Karma - The Flight Trainer
Replies: 23
Views: 1141

Re: Karma - The Flight Trainer

I remember being very excited reading about Karma in Micro User and Acorn User. Years later, I managed to get hold of the Flight Trainer (borrowed, so I no longer have the box), and it was... different from Elite. The UI was functional, and each control panel was basically a slab at the bottom of th...
by jregel
Sun Oct 13, 2019 5:49 pm
Forum: programming
Topic: What is (zp,X) actually useful for?
Replies: 10
Views: 515

Re: What is (zp,X) actually useful for?

I'm certainly not experienced enough in 6502 to add my own thoughts, but as I was recently reading "Advanced Machine Code Technique for the BBC Micro", I thought I'd post a bit of how Indexed Indirect Addressing is described: "... indexed indirect addressing is not a commonly used mode. One area in ...
by jregel
Sat Oct 12, 2019 11:44 am
Forum: hardware
Topic: Best display for a BBC?
Replies: 12
Views: 738

Best display for a BBC?

I'm currently running my Master with an RGB to SCART cable, connected to a Sony Trinitron 14" TV. It's pretty decent, but not something I'd want to run Mode 0 in for long sessions. So I'm looking for something that will give me a better display, but so many possible options... RGB -> SCART -> VGA/HD...
by jregel
Wed Oct 09, 2019 9:50 pm
Forum: for sale / freebies
Topic: More books from the attic . . .
Replies: 11
Views: 511

Re: More books from the attic . . .

Interested in the "Archimedes Operating System" (Dab) book, please.
by jregel
Sat Sep 14, 2019 9:49 pm
Forum: other vintage computer hardware, software and games
Topic: The 8-Bit Guy's new 65816 based computer
Replies: 54
Views: 3083

Re: The 8-Bit Guy's new 65816 based computer

David Murray has posted a new video with some updates on the project:

https://www.youtube.com/watch?v=sg-6Cjzzg8s

I thought it was interesting to see how this is developing.
by jregel
Tue Sep 03, 2019 10:17 am
Forum: hardware
Topic: A blitter for the beeb?
Replies: 118
Views: 11521

Re: A blitter for the beeb?

Hi Dominic When you originally posted your plans for the Blitter, you identified some features as "must-haves" and other as optional. Since that original post, you've developed some additional/different features such as faster CPU support, Copper, a co-pro with support for mapping X/Y co-ordinates t...
by jregel
Fri Aug 30, 2019 12:06 pm
Forum: hardware
Topic: A blitter for the beeb?
Replies: 118
Views: 11521

Re: A blitter for the beeb?

Another +1 from me. I'm watching this project with interest. Your plans are pretty ambitious in scope, so I've broken my comments into sections... Blitter For me, the most interesting part of the project is the ability to upgrade the Beeb's graphics capabilities, and the Blitter offers the possibili...
by jregel
Thu Aug 15, 2019 9:54 pm
Forum: hardware
Topic: BBC clock speed
Replies: 23
Views: 903

Re: BBC clock speed

Obviously there is the implication that each pixel takes two cycles, but can anyone explain what’s happening (or if I’m completely off track here)? You're sort of on the right track but you've forgotten about the borders :) If you look at p. 361 of the Beeb Advanced User Guide, you'll see that regi...
by jregel
Thu Aug 15, 2019 6:05 pm
Forum: hardware
Topic: BBC clock speed
Replies: 23
Views: 903

Re: BBC clock speed

Thanks again for all the comments. It’s taken a while for me to absorb it and do some more background reading… One follow-on question: The CRTC runs at 2Mhz when displaying the high resolution modes. So, in mode 0, there are 640 * 1bit pixels = 80bytes per scanline. There are 256 scanlines = 20480 b...
by jregel
Wed Aug 07, 2019 4:40 pm
Forum: hardware
Topic: BBC clock speed
Replies: 23
Views: 903

Re: BBC clock speed

Thanks again, everyone, both for the answers and bearing with my questions! I'm reading through all the replies and trying to get a handle on how it works. As Mark (1024MAK) recognised, I was seeing it a bit like a microprocessor, and find the bingo example helpful. Numerous comments have used the p...
by jregel
Wed Aug 07, 2019 1:30 pm
Forum: hardware
Topic: BBC clock speed
Replies: 23
Views: 903

Re: BBC clock speed

Thanks for all the replies! So am I right in understanding that the 6845 is the only other chip that reads from RAM, and that is writes a stream of bytes to the Video ULA? This occurs at either 1Mhz or 2Mhz, depending on screen mode. Why does the Video ULA need to run at 16Mhz? Is this related to do...
by jregel
Tue Aug 06, 2019 1:02 pm
Forum: hardware
Topic: BBC clock speed
Replies: 23
Views: 903

BBC clock speed

I’m trying to get a better handle on how the BBC works, in terms of its clock speed. The RAM in the BBC is clocked at 4Mhz. The 6502 is clocked at 2Mhz, so there is a further 2 million clock cycles that could be used to read/write RAM when the 6502 isn’t accessing it. How is this non-CPU time alloca...