Search found 1065 matches

by SarahWalker
Wed May 23, 2018 8:23 pm
Forum: emulators
Topic: Mac Arculator
Replies: 31
Views: 1503

Re: Mac Arculator

The !SICK numbers look about right for an ARM2 machine. The divide by zero error is most likely screen memory being too small - bumping that up to 480kb should fix it. It will probably also error out later on if ARCROM has been loaded, as it can't read the support ROM podule type.
by SarahWalker
Wed May 23, 2018 5:00 pm
Forum: emulators
Topic: Mac Arculator
Replies: 31
Views: 1503

Re: Mac Arculator

Excellent!

I did think of 64-bit incompatibilities as I went for a run this morning. I'm pretty sure I've had it working in the past, but I haven't done a 64-bit build for a while now - I need to give it a try and look for any issues!
by SarahWalker
Tue May 22, 2018 9:08 pm
Forum: emulators
Topic: Mac Arculator
Replies: 31
Views: 1503

Re: Mac Arculator

I keep doing that...

Fixed in rev 46.

What's the value of R15?
by SarahWalker
Tue May 22, 2018 8:08 pm
Forum: emulators
Topic: Mac Arculator
Replies: 31
Views: 1503

Re: Mac Arculator

If the POST is failing, RISC OS will put the failure code in fiq_r12 - this is printed as 'f12' in Arculator's register dump, and might give a clue as to what's going wrong?
by SarahWalker
Tue May 22, 2018 7:01 pm
Forum: emulators
Topic: Mac Arculator
Replies: 31
Views: 1503

Re: Mac Arculator

Rev 39 has the video code updates; these may help!
by SarahWalker
Tue May 22, 2018 6:25 pm
Forum: emulators
Topic: Mac Arculator
Replies: 31
Views: 1503

Re: Mac Arculator

Try setting either 'full_borders' or 'no_borders' to one. Having neither enabled is not currently supported - pity it's the default :) You could also try setting 'double_scan' to zero and see if that helps anything. I'm reworking this part of the video code though, so if you wait half an hour it mig...
by SarahWalker
Tue May 22, 2018 4:21 pm
Forum: emulators
Topic: Mac Arculator
Replies: 31
Views: 1503

Re: Mac Arculator

What's in arc.cfg? There are a few bugs in the video code currently, and you may be using one of the configurations that currently doesn't work. It's entirely possible that 'configurations that don't work' includes whatever's set as default...
by SarahWalker
Mon May 21, 2018 6:00 pm
Forum: emulators
Topic: Mac Arculator
Replies: 31
Views: 1503

Re: Mac Arculator

One thing to be aware of is that the guy who did the wxWidgets code for PCem implemented a sort of 'compatibility layer' in wx-utils.cc, to aid porting the GUI from Win32. I'd personally advice that Arculator _doesn't_ use this - I've found it to be quite confusing when trying to modify the GUI furt...
by SarahWalker
Fri May 18, 2018 6:13 pm
Forum: emulators
Topic: Mac Arculator
Replies: 31
Views: 1503

Re: Mac Arculator

My other (only?) active emulator, PCem, recently switched to wxWidgets + SDL2 for cross-platform UI goodness. I'd personally prefer that to Qt5, for the entirely selfish reason that I only have to learn one UI library :)
by SarahWalker
Tue May 15, 2018 5:20 pm
Forum: upcoming and recent events & exhibitions
Topic: ABUG SOUTH 1 to 3 June 2018 (Hampshire) BOOKING THREAD
Replies: 46
Views: 4070

Re: ABUG SOUTH 1 to 3 June 2018 (Hampshire) BOOKING THREAD

Will there be the usual amount of soldering type equipment around? My A3000 has died, and I have a greater chance of fixing it using decent equipment and with knowledgeable people in the vicinity :)
by SarahWalker
Mon May 14, 2018 7:40 pm
Forum: emulators
Topic: Video Timing
Replies: 31
Views: 1218

Re: Video Timing

HD6845SP is 'type 0'. A quick scan through Google Images suggests almost all Beebs use the HD6845SP, though I have a feeling that some Bs (possibly early ones?) use the Motorola 6845-1. While I was trying to find confirmation of the latter, I noticed that BeebMaster has a late Master 128 with a Sams...
by SarahWalker
Sun May 13, 2018 12:38 pm
Forum: software: other
Topic: SN76489 best sample playback?
Replies: 44
Views: 1077

Re: SN76489 best sample playback?

Interesting! I wonder if the shift register reset is one of the differences with the 'A' variant?
by SarahWalker
Sat May 12, 2018 4:40 pm
Forum: software: other
Topic: SN76489 best sample playback?
Replies: 44
Views: 1077

Re: SN76489 best sample playback?

The SN76489AN used in most (all?) BBCs does indeed reset the bit sequence when writing to the noise control register. I know the NCR 8496 does not (this is required by the LucasArts Tandy music driver), not sure about the other chips. Most then as I have one that doesn't and seems to be factory fit...
by SarahWalker
Sat May 12, 2018 10:56 am
Forum: software: other
Topic: SN76489 best sample playback?
Replies: 44
Views: 1077

Re: SN76489 best sample playback?

The SN76489AN used in most (all?) BBCs does indeed reset the bit sequence when writing to the noise control register. I know the NCR 8496 does not (this is required by the LucasArts Tandy music driver), not sure about the other chips.
by SarahWalker
Fri May 11, 2018 9:35 pm
Forum: software: other
Topic: SN76489 best sample playback?
Replies: 44
Views: 1077

Re: SN76489 best sample playback?

I had always assumed that volume changes take effect immediately, not being bound to the tone-generator clock. Is that not the case? I haven't really studied this massively in depth. However the behaviour I've seen when the SN's write signal isn't held for long enough, where it will seem to randoml...
by SarahWalker
Fri May 11, 2018 8:00 pm
Forum: software: other
Topic: SN76489 best sample playback?
Replies: 44
Views: 1077

Re: SN76489 best sample playback?

Has anyone successfully tried PWM on the Beeb? My understanding of the SN76489 is that it effectively updates at 4 MHz / 16 or 32, which would add severe quantisation to any PWM signal, limiting output quality. I had always assumed that volume changes take effect immediately, not being bound to the...
by SarahWalker
Fri May 11, 2018 6:04 pm
Forum: software: other
Topic: SN76489 best sample playback?
Replies: 44
Views: 1077

Re: SN76489 best sample playback?

Has anyone successfully tried PWM on the Beeb? My understanding of the SN76489 is that it effectively updates at 4 MHz / 16 or 32, which would add severe quantisation to any PWM signal, limiting output quality. The quality PCM over multiple voices is limited by the time taken between register writes...
by SarahWalker
Sat Apr 21, 2018 4:16 pm
Forum: off-topic
Topic: Safely working on older equipment?
Replies: 6
Views: 486

Safely working on older equipment?

I had some time off recently, and decided to try recapping an old PC motherboard that had stopped working. Having replaced all the capacitors, I powered on the board and one of the caps quickly went bang. Quickly powered off, replaced the blown cap on the thinking that maybe it was just bad, powered...
by SarahWalker
Sat Apr 21, 2018 6:57 am
Forum: for sale / freebies
Topic: IDE podules - 8 and 16 bit versions
Replies: 40
Views: 1741

Re: IDE podules - 8 and 16 bit versions

I'd like an 8-bit one please!
by SarahWalker
Mon Apr 02, 2018 4:37 pm
Forum: software: new games
Topic: Prince of Persia
Replies: 105
Views: 4096

Re: Prince of Persia

Just got a chance to play the finished version. Stunning stuff!
by SarahWalker
Sun Feb 25, 2018 3:58 pm
Forum: projects
Topic: New game - tube type thingy
Replies: 45
Views: 2990

Re: New game - tube type thingy

Oh go on then - https://www.youtube.com/watch?v=3miRyeavh7w&feature=youtu.be . A couple of other changes I didn't mention - I added a fog effect, as otherwise I found it a little difficult to differentiate between the limited draw distance and the track running out. Also I moved to a fixed game ...
by SarahWalker
Wed Feb 21, 2018 9:15 pm
Forum: projects
Topic: New game - tube type thingy
Replies: 45
Views: 2990

Re: New game - tube type thingy

Haven't posted an update for a bit! I've put the optimisation stuff aside, and started trying to make an actual game out of this. I put together a level editor - after the headache of writing the While Light editor in Win32, I wrote this one in C#, and made as much progress in a couple of hours as I...
by SarahWalker
Mon Jan 29, 2018 5:33 pm
Forum: software: new games
Topic: New Release: Retro Software's WHITE LIGHT by Sarah Walker
Replies: 68
Views: 5181

Re: New Release: Retro Software's WHITE LIGHT by Sarah Walker

Commie_User wrote:
SarahWalker wrote:I think I'm a real person, at least...


Is that your picture in the gallery?

If only!
by SarahWalker
Tue Jan 23, 2018 9:06 pm
Forum: projects
Topic: New game - tube type thingy
Replies: 45
Views: 2990

Re: New game - tube type thingy

How about checking to see if the 4 pixels you're about to write are the same as what's already there? Not sure how much use this will be over the Tube - I think you meant to say 'if the _host_ is indeed the bottleneck'? If the parasite is the bottleneck then this will surely just make it worse! I s...
by SarahWalker
Mon Jan 22, 2018 9:52 pm
Forum: projects
Topic: New game - tube type thingy
Replies: 45
Views: 2990

Re: New game - tube type thingy

How about checking to see if the 4 pixels you're about to write are the same as what's already there? Ooh, good catch! Just implemented this on the single processor version. While it doesn't quite fit into 3 frames with sprites onscreen, it does keep a nice stable 4 frames now. Overplotting the spr...
by SarahWalker
Sat Jan 13, 2018 1:27 pm
Forum: projects
Topic: New game - tube type thingy
Replies: 45
Views: 2990

Re: New game - tube type thingy

Bit of a philosophical question now - I've had a play with increasing the tube resolution on the copro version, from 64x56 to 64x112. This works, but drops performance slightly, from 16.7 fps back down to 12.5. Which do people prefer? 64x56, 16.7 fps - https://www.youtube.com/watch?v=QTwrO2SD734 64x...
by SarahWalker
Mon Jan 08, 2018 5:50 pm
Forum: projects
Topic: New game - tube type thingy
Replies: 45
Views: 2990

Re: New game - tube type thingy

On the master can you use a number of swr bank so that you have 70k of loads and writes to the screen buffer so no x or y indexes are used? The Master hasn't got 70k of SWRAM... In any case I'm currently using 1 bank for the source bitmap for the tunnel, and sprites currently spill to 2 banks and w...
by SarahWalker
Mon Jan 08, 2018 5:46 pm
Forum: projects
Topic: New game - tube type thingy
Replies: 45
Views: 2990

Re: New game - tube type thingy

20% ish... not a win then. That depends. Even 0% is a win if the extra 64K of RAM is useful. And with PiTubeDirect out there, it could be that there are more people with BBC B, sideways RAM, 6502 second processor (=112K) than a BBC Master (=128K). I think you might be confused here? The 20% was for...
by SarahWalker
Sun Jan 07, 2018 5:23 pm
Forum: projects
Topic: New game - tube type thingy
Replies: 45
Views: 2990

Re: New game - tube type thingy

OK. Hands up everyone who thought, based on the subject line, that this was going to be a game that took advantage of a second processor? (-8 Just implemented this, actually! The game still mostly runs on the host CPU, but the parasite is used to assist with the tube rendering. The parasite runs th...
by SarahWalker
Sun Jan 07, 2018 5:07 pm
Forum: projects
Topic: New game - tube type thingy
Replies: 45
Views: 2990

Re: New game - tube type thingy

62 cycles for LUT stuff, 20 cycles total for texture load, 83 cycles for store. So this would (in theory!) be 62*2 = 124 cycles for LUT, 20*2 = 40 cycles for texture load, plus some cycles to swap SWRAM banks between texture colour and texture colour*3 (12 at minimum), then 83 cycles for store. So 2...