Search found 144 matches

by ctr
Thu Jul 12, 2018 8:58 pm
Forum: emulators
Topic: Beebem Mode 7 glitch
Replies: 37
Views: 1038

Re: Beebem Mode 7 glitch

To me this implies double-height backgrounds only get copied down after Double Height 0x8D, and stop getting copied down after Normal Height 0x8C. I read it the other way. "The remaining Character Rectangles" refers to the character rectangles that aren't in double height. So the background is copi...
by ctr
Tue Jun 26, 2018 3:11 pm
Forum: software: other
Topic: BBC Micro Compendium by Jeremy Ruston
Replies: 55
Views: 1674

Re: BBC Micro Compendium by Jeremy Ruston

This might help. Maybe. I used Wolfram-Alpha to calculate the [3/3] pade approximant of (ln(1+x)-x)/x^2 (as used in BASIC2's LN) and then converted it to a continued fraction. This gave the same seven terms as calculating the continued fraction directly. Pade approximants of taylor series and trunc...
by ctr
Mon Jun 25, 2018 2:45 pm
Forum: software: other
Topic: Any short type-ins for unattended Beebs?
Replies: 91
Views: 4015

Re: Any short type-ins for unattended Beebs?

The redoubtable Bruce Clark has posted some type-ins over here: http://forum.6502.org/viewtopic.php?p=60765#p60765 In the third program edit line 60 to change the plus to a minus: - 60 PRINT CHR$(32+3*(C-INT(C)<.4)); + 60 PRINT CHR$(32-3*(C-INT(C)<.4)); I guess Apple BASIC uses +1 for TRUE. In the ...
by ctr
Mon Jun 25, 2018 2:39 pm
Forum: software: other
Topic: BBC Micro Compendium by Jeremy Ruston
Replies: 55
Views: 1674

Re: BBC Micro Compendium by Jeremy Ruston

I don't know if this is helpful, but somewhat to my amazement I've been able to find the original BBC BASIC program It is, but I now realise I got the wrong end of the stick. This is useful for the polynomial approximations, but not the continued fraction ones. I checked that the continued fraction...
by ctr
Fri Jun 22, 2018 10:54 pm
Forum: software: other
Topic: BBC Micro Compendium by Jeremy Ruston
Replies: 55
Views: 1674

Re: BBC Micro Compendium by Jeremy Ruston

C99 and C++17 both support hexadecimal floating point constants so it should be possible to exactly represent the beeb's 40-bit constants. Somehow I'd got the idea that early BBC Basic versions used the ratio of two polynomials, but that seems not to be the case. You were right. The beeb uses contin...
by ctr
Sun Jun 17, 2018 9:58 pm
Forum: stardot.org.uk
Topic: Post editing
Replies: 59
Views: 813

Re: Post editing

Unless there's some other code you're not posting which makes the css rule domain specific, adding things like that seem like a very bad idea to me. I would recommend using an element blocker like ublock origin for things like that. I like living dangerously! But it's a fair point. Here's a ublock ...
by ctr
Sun Jun 17, 2018 8:23 pm
Forum: stardot.org.uk
Topic: Post editing
Replies: 59
Views: 813

Re: Post editing

danielj wrote:
Sun Jun 17, 2018 6:32 pm
can the same be done in Chrome?
I don't use Chrome but a quick Google search suggests they removed the built-in feature. Apparently you can get add-ons for Chrome that let you do this.
by ctr
Sun Jun 17, 2018 6:26 pm
Forum: stardot.org.uk
Topic: Post editing
Replies: 59
Views: 813

Re: Post editing

Edit: there's a safer method below. You can hide these messages locally by adding .notice {display:none} to your browser's user-defined css. In Firefox this is in the file: C:\Users\<user>\AppData\Roaming\Mozilla\Firefox\Profiles\<profile>\chrome\userContent.css You could use greasemonkey to do some...
by ctr
Wed May 30, 2018 11:41 pm
Forum: software: other
Topic: Code Query with OSWORD Call
Replies: 4
Views: 221

Re: Code Query with OSWORD Call

Yes, that's right. I find it helpful to remember that the value at the top of the stack is always at &101+S (ignoring when S=&FF). I guess the original return address is still sitting there at &10B/C+X, and would need to be removed at some stage. At the start of .code2 it gets overwritten by the new...
by ctr
Wed May 30, 2018 8:13 pm
Forum: software: other
Topic: Code Query with OSWORD Call
Replies: 4
Views: 221

Re: Code Query with OSWORD Call

.code1 LDX #&07 .loop1 LDA &00A8,X ; Copy 8 values from &AF-&A8 to the stack. PHA DEX BPL loop1 PHA ; Create space on the stack PHA ; for a return address. TSX LDA &010B,X ; Copy the original return address STA &0101,X ; into the space just created. LDA &010C,X STA &0102,X RTS ; Return to the calle...
by ctr
Tue May 29, 2018 5:13 pm
Forum: emulators
Topic: Emulator setup to make all ROM area writes use bank 15 SWR
Replies: 23
Views: 475

Re: Emulator setup to make all ROM area writes use bank 15 SWR

I used a similar build system for my sideways ROM projects bitd. I had a Watford board, which works as you describe.

They build fine using beebem and the code ends up in RAM bank 4.
by ctr
Sun May 27, 2018 10:01 am
Forum: stardot.org.uk
Topic: Image sizes
Replies: 59
Views: 809

Re: Image sizes

I can't see the image either, whether logged in or out. If I use wget I get a straight 404 not found. Is it expecting a cookie to say you've accepted cookies? I've somehow avoided accepting the cookie permission thing. Edit: This is unlikely to be the problem. Other images work OK. It's just this one.
by ctr
Sat May 26, 2018 10:02 pm
Forum: stardot.org.uk
Topic: Image sizes
Replies: 59
Views: 809

Re: Image sizes

Whilst I'm on the subject of images - we allow linking to images in signatures - this breaks the ssl thing a bit, as external images might not be over secure links. I can turn this off, but it'd mean no images in sigs... Thoughts on that? Inline images have the same issue. This page shows an exclam...
by ctr
Sat May 26, 2018 9:46 am
Forum: off-topic
Topic: Forum GDPR compliance?
Replies: 58
Views: 896

Re: Forum GDPR compliance?

* Information (including any program content) posted on a forum is considered to be in the public domain, GDPR does not superceded a persons responsibility to protect their own information, or be accountable for what they disclose in public. In such cases existing laws still apply. I think it's wor...
by ctr
Sun May 13, 2018 10:02 pm
Forum: software: new games
Topic: New version of Scramble for the beeb (going well)
Replies: 64
Views: 3494

Re: New version of Scramble for the beeb (just starting)

Comparing it to frogger you've changed the horizontal sync width from 8 to 9 (R3 from &28 to &29). Is that a typo?
by ctr
Sun May 13, 2018 11:17 am
Forum: development tools
Topic: BeebAsm
Replies: 73
Views: 5285

Re: BeebAsm

No, thank you! That's brilliant. I've committed a new Windows exe. We might as well carry on in proposed-updates, it's easier to type and you've tagged the release if anyone wants to go back to that particular version. Though I committed the exe to master so that would have to be merged back in to p...
by ctr
Tue Apr 17, 2018 11:35 pm
Forum: software: other
Topic: How t pass arrays into procedures?
Replies: 14
Views: 856

Re: How t pass arrays into procedures?

On a real beeb keywords like COLOUR and PRINT are tokenised to a single byte when you enter a line of code, so abbreviating them doesn't make any difference to the memory used.
by ctr
Mon Apr 09, 2018 8:19 pm
Forum: software: other
Topic: Any short type-ins for unattended Beebs?
Replies: 91
Views: 4015

Re: Any short type-ins for unattended Beebs?

You could possibly shorten this by using a four-element array for the positions and a similar array for the velocities. 0REM Walking Lines 10MODE2 20VDU23,1,0;0;0;0; 30X%=640:Y%=512:A%=768:B%=768 40V%=32:W%=24:C%=16:D%=-28 50DIME%(7),F%(7),G%(7),H%(7) 60FORI%=1TO7 70GCOL3,I% 80MOVEE%(I%),F%(I%):DRAW...
by ctr
Fri Mar 30, 2018 12:55 am
Forum: software: new games
Topic: Prince of Persia
Replies: 114
Views: 5436

Re: Prince of Persia

Bravo!

This is brilliant. The graphics look incredible, the animation is absolutely rock solid and the sound works really well. And it's a good game!
by ctr
Sun Mar 25, 2018 8:04 pm
Forum: development tools
Topic: BeebAsm
Replies: 73
Views: 5285

Re: BeebAsm

Prime wrote:Also what is the currently worked upon branch of the source as I'd like to test the updates.....
https://github.com/stardot/beebasm/tree ... ed-updates

Note that the EXE isn't quite up-to-date. It does include all the new features.
by ctr
Sun Mar 25, 2018 4:31 pm
Forum: off-topic
Topic: Acorn Art Thread
Replies: 317
Views: 23425

Re: Acorn Art Thread

I'm loving these animations.

Having already written some code to convert the original pictures into MODE 2 format I extended it to handle the animations. A couple of ssds are attached.
by ctr
Sun Mar 18, 2018 10:04 pm
Forum: development tools
Topic: BeebAsm
Replies: 73
Views: 5285

Re: BeebAsm

I have had a look at rewriting the code to avoid the warnings by using ostringstream, which we already used in other places, so there's no new compatibility problem this way. This builds fine on Windows. The boot functionality works. I also tested a couple of the BASIC error messages and the rest l...
by ctr
Thu Mar 15, 2018 10:33 pm
Forum: development tools
Topic: BeebAsm
Replies: 73
Views: 5285

Re: BeebAsm

I merged my change. Yours looks good too.
by ctr
Thu Mar 15, 2018 4:32 pm
Forum: development tools
Topic: BeebAsm
Replies: 73
Views: 5285

Re: BeebAsm

I'm open to suggestions, but we could just #define (or 'const double our_pi = ...') our own constant here, if trying to use a library-provided value is causing problems. I can't see PI changing in the near future or across platforms. :-) I was thinking #undef/#define M_PI but you're right, a new co...
by ctr
Wed Mar 14, 2018 4:03 pm
Forum: development tools
Topic: BeebAsm
Replies: 73
Views: 5285

Re: BeebAsm

With gcc, M_PI seems to come from the platform math.h (via cmath), which on openbsd contains: #define M_PI ((double)3.14159265358979323846) /* pi */ Which is an old-style cast, hence the error. M_PI doesn't seem to come from any standard, so it's hard to say this is wrong, but the type of a real con...
by ctr
Tue Mar 13, 2018 4:38 pm
Forum: development tools
Topic: BeebAsm
Replies: 73
Views: 5285

Re: BeebAsm

Thank you Steve and Kieran, I can push to github now.

There's a new exe on github. The last commit is a fix to the buffer overflow identified by tricky in the previous post.
by ctr
Mon Mar 12, 2018 6:26 pm
Forum: development tools
Topic: Request membership of the Stardot organisation on GitHub here
Replies: 45
Views: 3995

Re: Request membership of the Stardot organisation on GitHub here

Please give me (mungre) permission to commit to beebasm. Thanks again.

Edit: To add some context, I asked SteveF who's currently maintaining beebasm but he's not an admin so he directed me here. I think what I'm actually asking for is to be added as a collaborator to beebasm.
by ctr
Mon Mar 12, 2018 5:12 pm
Forum: development tools
Topic: BeebAsm
Replies: 73
Views: 5285

Re: BeebAsm

For me, a single mention of my stardot username in the credits file is enough. More detail is available in the commit log. You could maybe change the copyright to something like "Copyright (C) Rich Talbot-Watkins and the contributors 2007 - 2018". I have updated the Visual Studio project files (to a...
by ctr
Fri Mar 02, 2018 5:09 pm
Forum: emulators
Topic: Emulation Request
Replies: 133
Views: 15314

Re: Emulation Request

As far as I can see fsd2fdi doesn't handle the complex cases of overlapping sector reads and the like. And it will never handle weak bits so a few games simply won't work with this approach. So there seem to be two options: * Create yet another file format that does handle weak bits. * Support fsd. ...
by ctr
Wed Feb 28, 2018 2:14 am
Forum: emulators
Topic: Emulation Request
Replies: 133
Views: 15314

Re: Emulation Request

In terms of what's practical for emulators, we know from Pernod earlier that MAME needs something it can turn into an MFM bit stream. So ambiguity on overlapping sectors is problematic. Yes, it's a problem, but it's exactly the problem we've got. How to handle the existing fsd files. As above, in m...