Search found 72 matches

by ctr
Fri May 26, 2017 1:57 pm
Forum: software: other
Topic: Exiting the current language?
Replies: 13
Views: 330

Re: Exiting the current language?

If you use OSHWM upwards then you're destroying the BASIC program, or word-processed document or whatever it is the user was working on. The data left in zero page is an obituary.

At this point there is no reason not to restart BASIC (or whatever) with a clean slate.
by ctr
Tue May 23, 2017 10:12 pm
Forum: software: other
Topic: Exiting the current language?
Replies: 13
Views: 330

Re: Exiting the current language?

As far as I know there is no way to exit all languages on the BBC B because there is nowhere else to go. (If you start the computer with no language ROM it displays "Language?" and stops. In this situation you can boot from a *RUNnable disk, but that's about it.) This doesn't matter though...
by ctr
Tue May 23, 2017 3:35 pm
Forum: hardware
Topic: Question about MEMC translation tables reprogramming
Replies: 12
Views: 209

Re: Question about MEMC translation tables reprogramming

Yes, access to physical memory requires supervisor mode. The audio memory is out of the way at 1F06000-1F07FFF.
by ctr
Tue May 23, 2017 2:27 pm
Forum: hardware
Topic: Question about MEMC translation tables reprogramming
Replies: 12
Views: 209

Re: Question about MEMC translation tables reprogramming

The only potential speed up from using physical memory I'm aware of, is to avoid checking for screen overruns by allowing code to write past &1FFFFFF into the physical memory range. This is also useful for hardware scrolling, as the screen is always mapped to physical pages 0 upward, and physic...
by ctr
Mon May 22, 2017 4:15 pm
Forum: software
Topic: Hacker needed ... for Zarch ;-)
Replies: 147
Views: 7302

Re: Hacker needed ... for Zarch ;-)

tlsa wrote:That screenshot doesn't look like it has dithering enabled to me. Is it the right one?

If you look over the top of the three rockets the furthest background is clearly dithered. If you load the image into a picture editor and zoom it you can see the foreground dithering too.
by ctr
Sun May 21, 2017 6:09 pm
Forum: general
Topic: 8bs.com
Replies: 6
Views: 309

Re: 8bs.com

cjr8bs commented further down that thread. He said the server was hacked and they intend to fix it.
by ctr
Sun May 21, 2017 12:31 pm
Forum: general
Topic: Today ZAP museum received....
Replies: 24
Views: 548

Re: Today ZAP museum received....

Phone calls were expensive. If the phone was placed conveniently there was a real danger of it being used.
by ctr
Thu May 18, 2017 3:30 pm
Forum: emulators
Topic: b2 - new emulator
Replies: 62
Views: 1076

Re: b2 - new emulator

Does it look the same with UI filtering on and with it off? (It's supposed to, and it does on my laptop at least.) If the UI filtering option is now redundant, I'll get rid of it... Four snapshots of the basic prompt with the filter dialog and messages window visible. I restarted the emulator befor...
by ctr
Thu May 18, 2017 1:02 am
Forum: emulators
Topic: b2 - new emulator
Replies: 62
Views: 1076

Re: b2 - new emulator

(As for whether there are further problems, I don't think so, but there's no shortage of evidence that I could be mistaken ;) The other SDL functions look to add the -0.5 offset in for you, so they should be fine as they are. But SDL_RenderGeometry just passes your vertex data straight through.) I ...
by ctr
Wed May 17, 2017 2:43 pm
Forum: emulators
Topic: b2 - new emulator
Replies: 62
Views: 1076

Re: b2 - new emulator

Yes, d3d11 has half pixel offsets by default, while d3d9 doesn't. Could explain the differences in various machines. Ah! The obvious explanation didn't occur to me. Maybe I'm the only person using the d3d9 rendering and it's just broken. If this is the case then a fix would be to add the offset in ...
by ctr
Wed May 17, 2017 1:30 am
Forum: emulators
Topic: b2 - new emulator
Replies: 62
Views: 1076

Re: b2 - new emulator

I tried d3d11. The good news is that I get the same results with and without the half pixel offset. The bad news is that it's comically broken on this ancient GPU. I tried the half-pixel text offset in a previous post. It has clear text but fuzzy menus as you'd expect. I'm really puzzled by this off...
by ctr
Tue May 16, 2017 10:31 pm
Forum: emulators
Topic: b2 - new emulator
Replies: 62
Views: 1076

Re: b2 - new emulator

I realised that it wasn't just the text but everything in the GUI that had the offset problem. I turned off the filtering and the text offset and hacked SDL's world transformation to move everything by half a pixel: diff --git a/src/render/direct3d/SDL_render_d3d.c b/src/render/direct3d/SDL_render_d...
by ctr
Tue May 16, 2017 3:14 pm
Forum: emulators
Topic: b2 - new emulator
Replies: 62
Views: 1076

Re: b2 - new emulator

I tried commit 1f8c690 which sets a text rendering offset. The text looks great! It is much better than the linear filter.
by ctr
Tue May 16, 2017 1:13 am
Forum: emulators
Topic: b2 - new emulator
Replies: 62
Views: 1076

Re: b2 - new emulator

I edited my previous comment while you were posting. The "linear" filter is an improvement.
by ctr
Tue May 16, 2017 12:36 am
Forum: emulators
Topic: b2 - new emulator
Replies: 62
Views: 1076

Re: b2 - new emulator

I built it on Windows with cmake 3.8.1. gen_6502.py failed because I've got python3. I replaced all the .iteritems() with .items() and that fixed it. You need to add python2 to the instructions as a prerequisite. I need to read the instructions. Building open source projects with lots of dependencie...
by ctr
Mon May 15, 2017 10:55 pm
Forum: emulators
Topic: b2 - new emulator
Replies: 62
Views: 1076

Re: b2 - new emulator

It's possible that a compiled language which supported coroutines as a native language feature might offer the best way to approach emulator code like this (as essentially what you have is a whole bunch of components running simultaneously), but I'm not aware of such a language (and coroutine libra...
by ctr
Mon May 15, 2017 8:46 pm
Forum: development tools
Topic: Request membership of the Stardot organisation on GitHub here
Replies: 35
Views: 1273

Re: Request membership of the Stardot organisation on GitHub here

Please add mungre on github. Thank you.
by ctr
Mon May 15, 2017 7:09 pm
Forum: emulators
Topic: b2 - new emulator
Replies: 62
Views: 1076

Re: b2 - new emulator

If I shrink the window the beeb text also gets all lumpy. There is no anti-aliasing going on. Please could you go to Tools|Messages, click Copy, and paste the output here? Renderer: direct3d, 736x576 SDL_PIXELFORMAT_ARGB8888 Sound: directsound, 48000Hz 1-channel (4096 byte buffer) Also what sort of ...
by ctr
Mon May 15, 2017 4:17 pm
Forum: emulators
Topic: b2 - new emulator
Replies: 62
Views: 1076

Re: b2 - new emulator

This makes such a realistic - and horrible - disc drive noise I thought something had gone wrong my laptop. Then I remembered I don't have a floppy drive! The timeline and clone features are really nice. I had thought of adding a state recorder to beebem but I needn't bother now. Is it possible to s...
by ctr
Mon May 08, 2017 3:12 pm
Forum: hardware
Topic: Palettemate / enhanced video ULA with 4096 colours
Replies: 240
Views: 7306

Re: Palettemate / enhanced video ULA with 4096 colours

And yes, if you read my post, I do say that there is sync circuitry. This drops the video signal to a lower level for the sync pulses. But it is simply a resistor that connects to a logic gate. There is no circuitry to enforce a set level. The sync circuit simply mixes the sync into the video signa...
by ctr
Mon May 08, 2017 12:19 am
Forum: hardware
Topic: Palettemate / enhanced video ULA with 4096 colours
Replies: 240
Views: 7306

Re: Palettemate / enhanced video ULA with 4096 colours

So my conclusion is, either the machine does not generate a "super black" level (it just uses the black border), or it is all done in the ULA. In composite video the sync pulses are periods of super-black so the beeb must generate them or TVs would lose sync when displaying a black screen...
by ctr
Fri May 05, 2017 8:07 pm
Forum: software & utilities for the pc, mac or unix
Topic: Writing to an ADFS partition in Linux
Replies: 7
Views: 656

Re: Writing to an ADFS partition in Linux

This week I found an alternative approach that may help others. Using the linux dd command I made an image of an IDE drive and found that I could open and write directly to the image using Arculator by simply renaming it to "HD4.HDF". If you mount the IDE drive at a directory called "...
by ctr
Fri May 05, 2017 3:02 pm
Forum: hardware
Topic: Fake, too slow, of just defective?
Replies: 20
Views: 456

Re: Fake, too slow, of just defective?

Coeus wrote:Thanks for a very useful tool - I first used this to validate CPU emulation fixes in B-Em but it has been just the job here as well.


I'm glad it helps. The "6502 detected" message means the CPU has the indirect jump bug, which is characteristic of NMOS versions.
by ctr
Fri May 05, 2017 11:34 am
Forum: hardware
Topic: Fake, too slow, of just defective?
Replies: 20
Views: 456

Re: Fake, too slow, of just defective?

This seemed to work reliably, at least for the testing so I was able to load tricky's menu-driven CPU test (which actually runs the Dorman tests, I believe) It's not tricky's it's mine! It does run Klaus Dormann's 6502 test with a couple of additions, and also Bruce Clark's BCD test. There is a mor...
by ctr
Sun Apr 30, 2017 11:26 am
Forum: software: games
Topic: New Release: Castle Defender
Replies: 30
Views: 1834

Re: New Release: Castle Defender

This new version is a real challenge. Recommended!
by ctr
Thu Apr 27, 2017 11:12 pm
Forum: off-topic
Topic: Why are domino plugs reversible?
Replies: 4
Views: 188

Re: Why are domino plugs reversible?

If Acorn had wired the socket with RTS diagonally opposite CTS and RX diagonally opposite TX then you could have used the same cable as both a modem cable and null-modem cable by rotating the connector 180°. I think. But they didn't. I always wondered if that was the point of the symmetrical connect...
by ctr
Tue Apr 18, 2017 7:02 pm
Forum: general
Topic: thebbclives website gone.
Replies: 26
Views: 1007

Re: thebbclives website gone.

Ahhh, thanks. I actually fixed all that lot over a year ago. Since then however, I've moved from old 32-bit hardware to brand spanking new 64-bit hardware and the application software has had quite the upgrade. The fix was to have a custom 404 error handler which could convert the old URL's on the ...
by ctr
Tue Apr 18, 2017 4:42 pm
Forum: software: games
Topic: New Release: Castle Defender
Replies: 30
Views: 1834

Re: New Release: Castle Defender

This is excellent. I have already spent far too long playing it. I thought the gameplay on the first two levels was well judged. Level one is easy once you figure out what you are doing, but it is the intro and it took me a while. I still haven't completed level two with full lives. Levels three and...
by ctr
Mon Apr 17, 2017 9:21 pm
Forum: general
Topic: thebbclives website gone.
Replies: 26
Views: 1007

Re: thebbclives website gone.

It is complete, however I'm hosting it on a non-PHP server and it was a PHP site to the fact that it runs at all is a bit of magic ;) If you can point me at the files you're having issues with accessing, I can fix those parts of the mirror so it is at least a bit more workable. Paul Many of the lin...
by ctr
Mon Apr 17, 2017 7:07 pm
Forum: hardware
Topic: BBC to VGA connector
Replies: 20
Views: 550

Re: BBC to VGA connector

SCART supports both RGB and composite video, but some TVs just ignore the RGB input. I once had a TV with two SCART sockets, but only one of the sockets supported RGB, so try both if that's an option. Also, you might need to choose RGB in a menu on the TV.

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