Search found 345 matches

by julie_m
Fri Oct 22, 2021 4:50 pm
Forum: development tools
Topic: Quick and dirty host-side BASIC line number remover/adder
Replies: 6
Views: 139

Re: Quick and dirty host-side BASIC line number remover/adder

By the way: which is the meaning of the 0xF22012E8 hex string searched for? It's what will be found at the address in memory where line 1000 begins. There will be &E8 (low byte of line number; 6502 BBC BASIC stores its line numbers high-byte first and we have already gone past the high byte, wh...
by julie_m
Thu Oct 21, 2021 8:36 pm
Forum: development tools
Topic: Quick and dirty host-side BASIC line number remover/adder
Replies: 6
Views: 139

Quick and dirty host-side BASIC line number remover/adder

This is the latest evolution of a tool I have been working on for stripping line numbers from BBC BASIC programs in order to edit them on the host, and reinserting them to run them on the target. #!/usr/bin/perl -w use strict; use constant { TRUE => 1, FALSE => "" }; use Getopt::Std; #use ...
by julie_m
Mon Oct 04, 2021 9:12 pm
Forum: programming
Topic: Reading a character from the screen?
Replies: 7
Views: 404

Re: Reading a character from the screen?

In BASIC, you probably want something like 10000 DEF FNscreen(X%,Y%) 10010 LOCAL A%,U% 10020 A% = &87 10030 VDU 31,X%,Y% 10040 U% = USR &FFF4 10050 = (U% AND &FF00) DIV &100 This moves the cursor to the given co-ordinates X%,Y%, calls OSBYTE with &87 in A, and populates U% with t...
by julie_m
Fri Sep 17, 2021 10:31 pm
Forum: development tools
Topic: Quick and dirty MODE 7 gfx from png
Replies: 1
Views: 184

Quick and dirty MODE 7 gfx from png

I knocked this up to create a MODE 7 screen from a 78*75 .png image: #!/usr/bin/perl -w use strict; use Image::Magick; my ($image, $err, $height, $width , $x, $y, $char); ######################### BEGIN FUNCTION DEFINITIONS ######################### sub read_pixel { my $x = shift; my $y = shift; my ...
by julie_m
Mon Sep 13, 2021 10:20 pm
Forum: programming
Topic: Intercepting WRCHV
Replies: 9
Views: 581

Re: Intercepting WRCHV

If you're going that way you may as well make orig_wrch be JP 0 as that's a lot easier to check: LDA orig_wrch+1:ORA orig_wrch+2:BEQ not_yet_intercepted If I used JMP 0 for ease of detection, then that would cause problems if newwrch were ever called before wrap_on had been called. Perhaps I am jus...
by julie_m
Sun Sep 12, 2021 11:06 pm
Forum: programming
Topic: Intercepting WRCHV
Replies: 9
Views: 581

Re: Intercepting WRCHV

But WRCHV will never point to &FFEE - &FFEE is the location of a JMP (WRCHV) instruction so if you ever point WRCHV to &FFEE you would get an infinite loop. I know WRCHV will never point to &FFEE. That address is hard-coded into a JMP instruction at orig_wrch, which subsequently get...
by julie_m
Sun Sep 12, 2021 7:06 pm
Forum: programming
Topic: Intercepting WRCHV
Replies: 9
Views: 581

Re: Intercepting WRCHV

And, I'm pleased to say, it worked second time! I just needed to get rid of a call from inside my buffer-flushing code to OSNEWL (since that goes through WRCHV), and make &0A flush the word buffer (since OSNEWL actually sends &0A then &0D). Now enabling it correctly saves the old content...
by julie_m
Fri Sep 10, 2021 12:43 am
Forum: programming
Topic: Intercepting WRCHV
Replies: 9
Views: 581

Re: Intercepting WRCHV

I'm guessing you're doing the "is it already in RAM" test so you can run your code multiple times and not get stuck in a loop. In the general case this could break (eg if something else had already taken the OSWRCH vector then you wouldn't update your orig values and so the JMP would go.....
by julie_m
Fri Sep 10, 2021 12:18 am
Forum: programming
Topic: Intercepting WRCHV
Replies: 9
Views: 581

Re: Intercepting WRCHV

I think it's more normal to just copy the old value to two bytes of data, then call it indirectly via JMP(...) like the OS does, rather than updating the JMP instruction itself. Not a big deal though. An indirect JMP takes an extra two cycles to read the real destination address; and bearing in min...
by julie_m
Thu Sep 09, 2021 10:46 pm
Forum: programming
Topic: Intercepting WRCHV
Replies: 9
Views: 581

Intercepting WRCHV

I've written some text wrapping / capital-after-full-stop code as part of my AdveBuilder adventure engine, which currently sits as a wrapper around OSASCI, called mainly from my text uncompression subroutine but also where there is a need to print raw text. However, I was wondering whether it might ...
by julie_m
Sat Aug 21, 2021 11:09 pm
Forum: programming
Topic: Odd "Syntax error"
Replies: 3
Views: 190

Re: Odd "Syntax error"

I've had the OSCLIOSCLIOSCLI stuff before, and modified my editing technique to avoid it.

Anyway, I've managed to reproduce the fault. Writing &00 to location &0C causes 'Syntax error'!

I'll find a BASIC IV disassembly and see what that address does.
by julie_m
Sat Aug 21, 2021 5:46 pm
Forum: programming
Topic: Odd "Syntax error"
Replies: 3
Views: 190

Odd "Syntax error"

A couple of times now I've called a buggy machine code subroutine and it has returned to BASIC with 'Syntax error'. The only thing I can see that might have been responsible is a STA 0,X which I guess could have stomped on some zero-page variable used by BASIC, if X was wrong, and messed up the inte...
by julie_m
Sun Aug 15, 2021 1:22 pm
Forum: new projects and releases: text and graphic adventures
Topic: A project 35 years in the making
Replies: 20
Views: 1206

Re: A project 35 years in the making

The latest version of Birthday Adventure is now live here https://github.com/JulieMontoya/AdveBuilder/blob/main/birthday_adv/birthday_adv.ssd and you can even play it in your web browser here ! I'm going to have to hit the "pause" button on AdveBuilder until I can get enough ideas together...
by julie_m
Sun Aug 15, 2021 9:16 am
Forum: 8-bit acorn emulators
Topic: Mac BeebEm Keyboard issues
Replies: 8
Views: 523

Re: Mac BeebEm Keyboard issues

I've also noticed the keyboard on my BeebEm on Mac (v5.0 (1)) sometimes goes unresponsive. Sometimes pressing and releasing left SHIFT is necessary to make certain yes such as "C" and "V" respond, and mis-pressing the `command` key can require a reset of BeebEm to fix. And someti...
by julie_m
Thu Aug 05, 2021 6:37 am
Forum: development tools
Topic: Setting up a BBC BASIC/6502 dev environment
Replies: 14
Views: 1056

Re: Setting up a BBC BASIC/6502 dev environment

BeebAsm is so popular because it has a very similar syntax to the assembler built into BBC BASIC, and it can also create disc images directly from your assembled code.
by julie_m
Wed Aug 04, 2021 8:27 pm
Forum: programming
Topic: Possible to run Acorn BBC Micro Language ROM on another 6502 system?
Replies: 100
Views: 3959

Re: Possible to run Acorn BBC Micro Language ROM on another 6502 system?

I think it's pretty common on the Beeb to have different load and execution addresses. If I'm writing something that is basically a library with multiple points to be called by a program possibly in a high-level language, as opposed to a machine code program with a single entry point, I like to poin...
by julie_m
Wed Aug 04, 2021 8:20 pm
Forum: development tools
Topic: Setting up a BBC BASIC/6502 dev environment
Replies: 14
Views: 1056

Re: Setting up a BBC BASIC/6502 dev environment

There are plenty of developers using naught but vi in a terminal ..... I'm not quite so minimalist. Kate is my weapon-of-choice. It provides a built-in terminal, which I use to run BeebAsm and git and then minimise during editing. Kate also understands vi commands. Or you can use sed -I on a file, a...
by julie_m
Thu Jul 29, 2021 7:09 am
Forum: development tools
Topic: BeebAsm
Replies: 206
Views: 27010

Re: BeebAsm

OK. I think it worked! Making my own fork was the crucial bit I was missing. So if I got everything right, you should be seeing a pull request from JulieMontoya (for I am her, at least over there) wanting to add two files, `examples/jump_table_at_end.6502` with the actual code and `examples/jump_tab...
by julie_m
Wed Jul 28, 2021 10:32 pm
Forum: development tools
Topic: BeebAsm
Replies: 206
Views: 27010

Re: BeebAsm

OK ..... I have commented my example program even more thoroughly, made my own local repository and switched branches to proposed-updates ..... used git add to add my own files, and done git commit. My repo is one commit ahead. Sorry for being a n00b, but what do I do now? Either in GitHub or in Bash?
by julie_m
Tue Jul 27, 2021 11:01 pm
Forum: new projects and releases: text and graphic adventures
Topic: A project 35 years in the making
Replies: 20
Views: 1206

Re: A project 35 years in the making

Thank you! *curtsey* I have to say, you aren't the only person who got stuck there; so I'll make a final version with an extra clue or two so nobody gets left in the dark. I've made some improvements to the game engine -- it can now SAVE and RESTORE a position, and RESTART a game from the beginning,...
by julie_m
Tue Jul 27, 2021 2:41 pm
Forum: development tools
Topic: BeebAsm
Replies: 206
Views: 27010

Re: BeebAsm

I've recently started using GitHub "properly" (with a proper local file structure and everything, as opposed to like a kind of glorified Pastebin) so I will certainly investigate how to do that.
by julie_m
Sun Jul 25, 2021 12:37 pm
Forum: development tools
Topic: BeebAsm
Replies: 206
Views: 27010

Re: BeebAsm

I don't know if this is worth adding to the manual, but here's how to create code, such as a jump table, that always ends on a page boundary: ORG &7B00 ._begin .real_wibble LDX #wibble_msg MOD 256 LDY #wibble_msg DIV 256 JMP real_sayXY .real_blah LDX #blah_msg MOD 256 LDY #blah_msg DIV 256 .real...
by julie_m
Sun Jul 18, 2021 10:38 am
Forum: new projects and releases: text and graphic adventures
Topic: A project 35 years in the making
Replies: 20
Views: 1206

Re: A project 35 years in the making

Here's the link to the latest version of the project, now with docs beginning to appear in the Wiki and everything: https://github.com/JulieMontoya/AdveBuilder Birthday Adventure is mentioned as an example of what can be done with AdveBuilder. There's a link to a playable SSD right on the front page...
by julie_m
Wed Jul 14, 2021 7:26 am
Forum: 8-bit acorn software: other
Topic: Quicksort implementations for the BBC Micro?
Replies: 23
Views: 989

Re: Quicksort implementations for the BBC Micro?

That sounds more like a selection sort, which moves the first item straight to the beginning and then iterates over fewer items on each subsequent pass. It requires fewer swap operations than a bubble sort, but also requires you to keep track of more than one position at any one time. An insertion s...
by julie_m
Tue Jul 13, 2021 8:37 pm
Forum: new projects and releases: text and graphic adventures
Topic: A project 35 years in the making
Replies: 20
Views: 1206

Re: A project 35 years in the making

Didn't Twin Kingdom Valley have a weird thing going on with directions, where if you typed an unavailable direction it would take the nearest available exit? For instance if you typed N and there was no exit North but NW was available, it would take you NW. The Scott Adams games also allowed you to ...
by julie_m
Mon Jul 12, 2021 10:59 pm
Forum: new projects and releases: text and graphic adventures
Topic: A project 35 years in the making
Replies: 20
Views: 1206

Re: A project 35 years in the making

I had always thought that it was a bit unrealistic to be able to identify by feel an object picked up in darkness, but not to be able to retrace your steps into the light, or dead-reckon your way along a passage you have already seen illuminated. It would actually be very easy to add a "tell by...
by julie_m
Sun Jul 11, 2021 8:55 pm
Forum: new projects and releases: text and graphic adventures
Topic: A project 35 years in the making
Replies: 20
Views: 1206

Re: A project 35 years in the making

Oh, yes! I came up with a really fiendish puzzle that was just too much for a quick 8-room demo (although it would have made a good test case for polystate objects ..... Birthday Adventure only uses bi-state objects), so that is going to need working into a suitable scenario, just because it would b...
by julie_m
Sun Jul 11, 2021 8:24 am
Forum: new projects and releases: text and graphic adventures
Topic: A project 35 years in the making
Replies: 20
Views: 1206

Re: A project 35 years in the making

OK, the code with some documentation very much in-progress is now at https://github.com/JulieMontoya/Random_Beeb_Stuff/tree/main/birthday_adv -- you will need BeebASM (link to a universal .deb package I created), and you may need to run sudo apt install libdbd-sqlite3-perl (or its equivalent on MacP...
by julie_m
Sat Jul 10, 2021 8:20 pm
Forum: new projects and releases: text and graphic adventures
Topic: A project 35 years in the making
Replies: 20
Views: 1206

Re: A project 35 years in the making

I thought (well, hoped .....) someone might be, so I'm currently bashing out some notes to post alongside it on GitHub. I can already see some potential improvements with the way "examine" messages are stored; I think, due to the "fully-variable length" record structure I am usin...
by julie_m
Sat Jul 10, 2021 7:43 pm
Forum: new projects and releases: text and graphic adventures
Topic: A project 35 years in the making
Replies: 20
Views: 1206

Re: A project 35 years in the making

That might simply be because there is so little of it (the disc image was built to be able to run in MODE 6, so no reason Electron users should miss out :) ) ..... Now I have the engine code in a usable state, though, I will be able to put it through its paces with something a bit more complex.

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