Search found 93 matches

by ctr
Tue Sep 26, 2017 8:04 pm
Forum: programming
Topic: Using memory below &0E00 from BASIC
Replies: 34
Views: 984

Re: Using memory below &0E00 from BASIC

So, for some reason BBC BASIC makes a distinction between 'immediate commands' like LIST, SAVE, etc, and the rest. You can't execute them in a program (they yield "Syntax error"), unlike most other BASICs. I'm not sure where it is but there's obviously an explicit check for this somewhere...
by ctr
Mon Sep 04, 2017 7:52 pm
Forum: emulators
Topic: Latest version of BeebEm
Replies: 24
Views: 2084

Re: Latest version of BeebEm

I've seen the Revs bug elsewhere and I've been meaning to look at it for a while, so I've pushed a fix . Sadly, this doesn't help The Shapes Game. That bug looks like a timing problem. The top half of the main sprite is sometimes fine, sometimes flickers and sometimes disappears, depending where on ...
by ctr
Mon Aug 28, 2017 3:40 pm
Forum: development tools
Topic: beebasm putbasic problem
Replies: 9
Views: 467

Re: beebasm putbasic problem

sydney wrote:I'm sure I'd read line numbers were optional.

That rang a bell so I had another look. Github has a bunch of proposed updates including automatic line numbering. Stardot has a thread about it.
by ctr
Mon Aug 28, 2017 2:29 pm
Forum: development tools
Topic: beebasm putbasic problem
Replies: 9
Views: 467

Re: beebasm putbasic problem

You can't omit the line numbers in your basic code. This is a nuisance.
by ctr
Wed Aug 23, 2017 11:05 pm
Forum: programming
Topic: How do you save a screen
Replies: 448
Views: 15714

Re: How do you save a screen

png might be a better choice. The last picture, "Toxic Wastedump.jpg", is 215KB. Converted to indexed png it is 10KB, and guaranteed lossless.
by ctr
Fri Aug 18, 2017 10:01 pm
Forum: projects
Topic: Starting a Prince of Persia port...
Replies: 129
Views: 7905

Re: Starting a Prince of Persia port...

I'm not sure which assembler was originally used but the syntax is slightly different and it has a couple of more advanced features than BeebAsm, including the ability to identify local labels and variables for reuse. In beebasm you can use braces {} to create blocks. Labels and variables are local...
by ctr
Mon Aug 07, 2017 5:43 pm
Forum: software: games - high scores
Topic: High Score Challenge S7- Champ - Rocket Raid
Replies: 63
Views: 1610

Re: High Score Challenge S7- Champ - Rocket Raid

These are exactly the symptoms that I've been facing and it's extremely frustrating because it should be a bit smoother. I'm not sure if it's an emulator issue or if it happens in hardware too. I played this on real hardware last time it was part of the challenge and was able to get past the maze p...
by ctr
Mon Aug 07, 2017 5:20 pm
Forum: software: games - high scores
Topic: High Score Challenge S7- Champ - Rocket Raid
Replies: 63
Views: 1610

Re: High Score Challenge S7- Champ - Rocket Raid

After more than thirty years I finally completed a raid! I am absurdly pleased. Then I had no spare lives and died on level 2 (duh!) so I only scored 21,220. There seem to be no points for finishing. http://stardot.org.uk/forums/download/file.php?mode=view&id=31289 My best score of 25,030 was ac...
by ctr
Tue Aug 01, 2017 5:43 pm
Forum: emulators
Topic: Music 5000 in B-Em
Replies: 88
Views: 4690

Re: Music 5000 in B-Em

As a complete new person to this I've got a couple of funnies that would be good to sort out if anyone can help? From the user guide it says key F0 to get back to the main menu - Ah! no F0 function key here - is there a way back? And I wanted to save my O&L masterpiece! - but getting a READ ONL...
by ctr
Tue Aug 01, 2017 3:46 pm
Forum: emulators
Topic: Music 5000 in B-Em
Replies: 88
Views: 4690

Re: Music 5000 in B-Em

a large source of AMPLE music with accompanying MP3 files (recorded directly from the Music 5000 hardware) at http://amplinex.tumblr.com/. This is excellent. I stumbled across it a couple of months ago while looking for some music to test beebem. I did notice one minor hiccup: disk 22 seems to be a...
by ctr
Sat Jul 29, 2017 6:39 pm
Forum: hardware
Topic: AMX mouse
Replies: 4
Views: 290

Re: AMX mouse

Just type *ART to start a drawing program. Click the mouse button to make the "Bad name" error go away.
by ctr
Mon Jul 24, 2017 9:39 pm
Forum: hardware
Topic: *mzap and *define
Replies: 12
Views: 609

Re: *mzap and *define

I don't know which rom you're thinking of, but here's one I made earlier. The command is *DESIGN and it always starts at character 224. It uses the arrow keys, return to draw a pixel and del to delete. shift+arrow key moves the cursor to the far edge. ctrl+arrow key moves the image around. f0 and f1...
by ctr
Thu Jul 20, 2017 3:37 pm
Forum: software: other
Topic: osbyte call ? and which adress
Replies: 4
Views: 314

Re: osbyte call ? and which adress

I should have looked at the beeb wiki in the first place:

OSBYTE 129 with X=0 and Y=255 reads the OS version.

The original code is saying if this isn't an Electron then partially reset the NETV vector.

OSBYTE 163 checks for various extensions.
by ctr
Thu Jul 20, 2017 12:07 pm
Forum: software: other
Topic: osbyte call ? and which adress
Replies: 4
Views: 314

Re: osbyte call ? and which adress

&FFB7 holds the address of the default vector table. As seen here . !&FFB7 is the address of the default vector table (&D940 on OS 1.20). ?(&24+!&FFB7) is the low byte of the default NETV vector. ?&224 is the low byte of the NETV vector. So you are replacing the low byte of t...
by ctr
Sat Jul 15, 2017 11:40 pm
Forum: software: new games
Topic: New Games Index
Replies: 24
Views: 1534

Re: New Games Index

The link to my Tetris game should be tetris.ssd.zip.

The original Stardot thread had an old version in the top post. I've updated it now.
by ctr
Thu Jun 29, 2017 7:59 pm
Forum: emulators
Topic: BeebEm capture video in Windows 8
Replies: 8
Views: 1713

Re: BeebEm capture video in Windows 8

It has recently been fixed. The fix will be in the next release.
by ctr
Wed Jun 28, 2017 12:25 am
Forum: software: other
Topic: Confused about boot file
Replies: 4
Views: 334

Re: Confused about boot file

The break key is function key 10. When you press break the OS puts the (notional) key code for f10 into the keyboard buffer. When a program asks for keyboard input the function key definition is returned one character at a time until it is exhausted. e.g. try typing "*KEY10 HELLO" and pres...
by ctr
Tue Jun 06, 2017 3:24 pm
Forum: hardware
Topic: OS RAM module
Replies: 79
Views: 3827

Re: OS RAM module

In BASIC2 LOMEM and HIMEM are freely assignable.

Code: Select all

>LOMEM=&C000:HIMEM=&E000
>PRINT~LOMEM,~HIMEM
      C000      E000

I don't know if the rest of BASIC would cope with this.
by ctr
Sat Jun 03, 2017 5:48 pm
Forum: programming
Topic: Break/continue in BASIC loops?
Replies: 20
Views: 561

Re: Break/continue in BASIC loops?

If you exit a loop with a GOTO then the loop remains active. The terminator of the next loop will actually jump back to the previous still-active loop. An example might be clearer: 10FORI%=1TO20 20PRINT"I ";I% 30PROCLOOP 40NEXT 50END 60DEFPROCLOOP 70FORJ%=1TO6 80PRINT"J ";J% 90IF...
by ctr
Thu Jun 01, 2017 4:54 pm
Forum: programming
Topic: 6502 BASIC Compiler
Replies: 25
Views: 1362

Re: 6502 BASIC Compiler

So if I understand the article correctly the summary is. - compiled code much faster unless float based - Compiler code size much bigger ( ABC has runtime library, riscbasic adds to each program) - restrictions on code, more so with ABC They both support libraries, Like *link on mdfs, but requires ...
by ctr
Thu Jun 01, 2017 2:25 pm
Forum: emulators
Topic: Latest version of BeebEm
Replies: 24
Views: 2084

Re: Latest version of BeebEm

4.15 is close to being released.

jgh's VDFS changes were a last-minute addition and there is still some discussion. (I'm mungre there.)

And Mike Wyatt has just pushed Music 5000 emulation.
by ctr
Fri May 26, 2017 1:57 pm
Forum: software: other
Topic: Exiting the current language?
Replies: 13
Views: 802

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: 802

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: 447

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: 447

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: 159
Views: 10652

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: 10
Views: 824

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: 47
Views: 2278

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: 66
Views: 3264

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: 66
Views: 3264

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 ...

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