Search found 170 matches

by julie_m
Sun Jul 12, 2020 8:54 pm
Forum: 8-bit acorn software: other
Topic: Halcyon?
Replies: 4
Views: 146

Re: Halcyon?

HALCIEN -- High level ALgorithmic Computer Instruction ENcoding language.

I remember the adverts in The Micro User. It seemed to be some sort of 3D graphics language. But that's about all I remember .....
by julie_m
Sat Jul 11, 2020 7:06 pm
Forum: programming
Topic: Sprite Masking
Replies: 26
Views: 926

Re: Sprite Masking

BUG ALERT:
The loop-terminating test after the INX should be BEQ, otherwise it will not work with 256-byte-long sprites. :oops:
by julie_m
Fri Jul 10, 2020 9:48 pm
Forum: programming
Topic: Sprite Masking
Replies: 26
Views: 926

Re: Sprite Masking

I remember now although never did anything as clever as that, the essence of it, plotting over again to erase before moving and replotting. How is the background restored when you don't know what colour it's going to be? Because it does not matter what colour the background was! The truth table for...
by julie_m
Fri Jul 10, 2020 9:14 pm
Forum: 8-bit acorn software: classic games
Topic: Methods and ethics of cheating in retro computer games
Replies: 12
Views: 418

Re: Methods and ethics of cheating in retro computer games

For me, as a natural born hacker™, cheating at games was just a way of adding a new dimension to the entertainment. First there was the thrill of the chase: discovering how to hack a game was a fun challenge in its own right! Sometimes there was a layer of protection to be defeated. Once you could g...
by julie_m
Fri Jul 10, 2020 5:50 pm
Forum: 8-bit acorn software: other
Topic: How to back up a cassette's program?
Replies: 2
Views: 126

Re: How to back up a cassette's program?

Your best option might be to clean the audio up digitally using Audacity or similar. There will only be two frequencies in it. Just filter out anything else.
by julie_m
Thu Jul 09, 2020 9:45 pm
Forum: programming
Topic: Self Modifying Code
Replies: 12
Views: 434

Re: Self Modifying Code

Welcome to the dark side... ;) Thanks -- I think I might like it over here 8) I've posted my effort so far in another thread here . Probably best to stick to that thread for discussing the specific application (direct manipulation of screen memory in a time-critical fashion) and keep this thread fo...
by julie_m
Thu Jul 09, 2020 9:15 pm
Forum: programming
Topic: Sprite Masking
Replies: 26
Views: 926

Re: Sprite Masking

Here's my effort so far! I have working subroutines to calculate the start of screen memory given X and Y co-ordinates; plot a sprite directly onto the screen; and grab data from screen to use as a sprite. Here I'm storing the location of data in a zero page pointer as though to use with a (zp),Y in...
by julie_m
Thu Jul 09, 2020 2:35 pm
Forum: 8-bit acorn software: other
Topic: Beeb graphics ripper
Replies: 25
Views: 3406

Re: Beeb graphics ripper

There's my "dfsbuster" tool on Github, if you have nothing better. The latest version can even detokenise BASIC programs!

https://github.com/JulieMontoya/DFSBuster
by julie_m
Thu Jul 09, 2020 1:15 am
Forum: programming
Topic: Self Modifying Code
Replies: 12
Views: 434

Re: Self Modifying Code

Ah, I think I've properly got the hang of this now! The new code more or less just dropped over the old, apart from taking one of its parameters in a different address pair and using zero page entirely differently since I managed to eliminate a bunch of temporary variables! I even spotted a place wh...
by julie_m
Thu Jul 09, 2020 1:02 am
Forum: programming
Topic: Sprite Masking
Replies: 26
Views: 926

Re: Sprite Masking

There is an even fancier trick you can use. That is to EOR a sprite with a shifted version of itself. Then you can EOR this against what is already on the screen, to remove the sprite from its old position and redraw in in its new position in a single operation. Depending how many animation frames y...
by julie_m
Wed Jul 08, 2020 9:50 pm
Forum: programming
Topic: Self Modifying Code
Replies: 12
Views: 434

Re: Self Modifying Code

Well, I've tried it, and it works! My computer did not go on fire or anything. It just draws on the screen, and does it very fast.

Unfortunately, I seem somehow to have reproduced a bug from my earlier, slower (?) version. But debugging is the fun of programming, isn't it?
by julie_m
Wed Jul 08, 2020 9:41 pm
Forum: programming
Topic: Sprite Masking
Replies: 26
Views: 926

Re: Sprite Masking

Hmmmm, I think we might be on the same page here! I'm currently working on some code to draw sprites on screen, using a dodgy-sounding (but very fast! and in the grand scheme of things, harmless) technique: self-modifying code! It isn't quite ready to post yet, but as soon as it is working as I want...
by julie_m
Tue Jul 07, 2020 11:28 pm
Forum: programming
Topic: Reading shift key status from BASIC
Replies: 5
Views: 169

Re: Reading shift key status from BASIC

Note that negative parameters to INKEY can be used to check the status of any individual key; there is a table in the User Guide. If you use a FOR loop something like this: 100K%=0 110REPEAT 120FORI%=-1TO-127STEP-1 130IFINKEYI%K%=I%:I%=-127:PRINT"INKEY(";K%;")=-1" 140NEXTI% 150UNTILK% you have the b...
by julie_m
Tue Jul 07, 2020 11:13 pm
Forum: development tools
Topic: BeebAsm
Replies: 100
Views: 11351

Re: BeebAsm

That looks like the page I found. Certainly the versions match ..... Anyway, GitHub is behaving itself in my now-upgraded browser; probably the unfinished upgrade broke the clone link.
by julie_m
Tue Jul 07, 2020 9:36 pm
Forum: development tools
Topic: BeebAsm
Replies: 100
Views: 11351

Re: BeebAsm

The Github link seemed to point just to the Wiki section and didn't seem to have any way to clone the code. Thinking about it, my laptop crashed horribly shortly after I downloaded it, so it's possible my browser was misbehaving unbeknownst to me. Anyway. Here is my new, improved Debian / Ubuntu / M...
by julie_m
Tue Jul 07, 2020 8:40 pm
Forum: programming
Topic: Self Modifying Code
Replies: 12
Views: 434

Self Modifying Code

Self-modifying code is seen as a big no-no nowadays, with modern processors having cache, execution protection and microcontroller having lots of ROM. But back in the days, it was actually necessary. If you didn't have a stack, you had to store your own return address into a jump instruction; and if...
by julie_m
Tue Jul 07, 2020 6:20 pm
Forum: 8-bit acorn software: other
Topic: Micronova Systems Limited PCB CAD
Replies: 8
Views: 670

Re: Micronova Systems Limited PCB CAD

I hope you manage to get this going again. I'd really like to see someone else's attempt at PCB CAD on a Beeb !
by julie_m
Mon Jul 06, 2020 9:02 pm
Forum: development tools
Topic: BeebAsm
Replies: 100
Views: 11351

Re: BeebAsm

I could only find an older version than that. And the problem I had was that, even despite the existence of a Linux Support Patch, it didn't link against the maths library; so I had to poke about with the Makefile. So it looks like my hard work making this .deb package might have been in vain. Excep...
by julie_m
Mon Jul 06, 2020 7:32 am
Forum: development tools
Topic: BeebAsm
Replies: 100
Views: 11351

Re: BeebAsm

I recently discovered BeebAsm and I have to say, I am very impressed with it! It's almost exactly the program I would have written myself. It's so compatible with BBC BASIC's built-in assembler that you can just turn a BeebAsm project back into a native Beeb project. (I'm always conscious that if yo...
by julie_m
Wed Jun 24, 2020 7:04 am
Forum: 8-bit acorn software: other
Topic: Any condensed font, say 6px wide?
Replies: 12
Views: 608

Re: Any condensed font, say 6px wide?

BigEd wrote:
Mon Jun 01, 2020 12:32 pm
Proportional is a nice idea: why should "I" need to be as wide as "M" needs to be.
Systems with character-mapped screens used to be quite common. The display memory only needed to store ASCII codes, not bit patterns. This had the side-effect of requiring fixed character spacing.
by julie_m
Sat Jun 20, 2020 6:33 pm
Forum: 8-bit acorn software: other
Topic: Word processing advice
Replies: 35
Views: 1156

Re: Word processing advice

128Kbytes of ROM (a full 27010) will occupy eight 16KB banks, and if you use just one 74HC138 they will have to be 0-7. That will still leave banks 8-B for 64KB of sideways RAM, F for BASIC (where it has to be anyway) and C-E for any other three ROMs. (I'd expect there to be a small amount of code d...
by julie_m
Fri Jun 19, 2020 8:47 pm
Forum: 8-bit acorn software: other
Topic: Word processing advice
Replies: 35
Views: 1156

Re: Word processing advice

I get the part that there is some soldering to be done, but I'm quite what the numers are and what the result is in the end... #-o The 74HC138 takes the 4 ROM bank select lines and the !RD line and energises one of 8 active-low outputs, depending which of either banks 0-7 or 8-F is selected. (Which...
by julie_m
Fri Jun 19, 2020 7:56 pm
Forum: 8-bit acorn software: other
Topic: Word processing advice
Replies: 35
Views: 1156

Re: Word processing advice

It should be possible, using a 74HC138, some diodes and a bit of crazy soldering nobody is ever going to see ;) to bodge a bigger EPROM into any Beeb so as it will take up 2 (with a 27256, or wasting half of a 27512; though in that case, you might as well copy the other two ROMs -- probably 27128s -...
by julie_m
Tue Jun 16, 2020 10:16 pm
Forum: 8-bit acorn software: other
Topic: Basic is great, but what else ?
Replies: 8
Views: 373

Re: Basic is great, but what else ?

Sophie Wilson's original BBC BASIC is a fast implementation, and it's running on hardware without unnecessary slowdowns (for instance, the screen can be scrolled by changing the address where its representation starts in memory; it doesn't require shifting a whole kilobyte every time a line of text ...
by julie_m
Mon Jun 15, 2020 11:32 pm
Forum: 8-bit acorn software: other
Topic: BCP: a BBC Micro printed circuit design program
Replies: 58
Views: 5631

Re: BCP: a BBC Micro printed circuit design program

It is now back to working well enough to drop a disc image:
bcpdemo8.ssd
(132.5 KiB) Downloaded 4 times
Currently working on photoplotting routines .....
by julie_m
Sat Jun 13, 2020 11:04 pm
Forum: 8-bit acorn software: other
Topic: BCP: a BBC Micro printed circuit design program
Replies: 58
Views: 5631

Re: BCP: a BBC Micro printed circuit design program

Well, I think I have found most of what was up with it. And as usual, it was something I messed about with ..... Of course, I would not have called it "messing about with it" if it had worked, so that's pretty much a given anyway. There is a label redefinition left over from where I botched trying t...
by julie_m
Sat Jun 13, 2020 8:35 pm
Forum: 8-bit acorn software: other
Topic: BASIC questions.
Replies: 36
Views: 3715

Re: BASIC questions.

If you just want to throw an error in a machine code routine and have BASIC trap it, try something like this: 10DIMcode%256 20P%=code%:[ 30.error 40BRK \ begin custom error 50EQUB72 \ this is what ERR will contain 60EQUS"Wibble" \ message 70BRK \ needed to mark end of message 80] 90ONERRORGOTO1000 1...
by julie_m
Fri Jun 12, 2020 10:15 pm
Forum: 8-bit acorn software: other
Topic: Word processing advice
Replies: 35
Views: 1156

Re: Word processing advice

I loved Wordwise Plus. The fact of entering text in a 40-column screen when it probably would be printed out using 80 columns (perhaps less; with 80 characters across 200mm. of the 210mm. wide page, an extra centimetre either side would leave 72 columns usable) and the use of embedded codes to indic...
by julie_m
Sun Jun 07, 2020 7:18 pm
Forum: 8-bit acorn software: other
Topic: BCP: a BBC Micro printed circuit design program
Replies: 58
Views: 5631

Re: BCP: a BBC Micro printed circuit design program

Sorry for the lack of updates recently (and so much for "I can work on BCP while I'm stuck indoors") -- I've been doing mostly boring stuff, like rearranging code, based on the realisation that what I wanted to add into the graphics library would take it beyond the available space. And going back to...
by julie_m
Thu May 14, 2020 4:21 pm
Forum: 8-bit acorn software: other
Topic: Creating a !BOOT file
Replies: 13
Views: 1541

Re: Creating a !BOOT file

You can also use something like

Code: Select all

10*SPOOL!BOOT
20PRINT"CHAIN""PROG"""
30*SPOOL
40*OPT4,3
to generate an !BOOT file from BASIC.

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