Search found 312 matches

by dominicbeesley
Wed Jul 26, 2017 3:55 pm
Forum: software: other
Topic: 6809 Co Pro Client ROM
Replies: 19
Views: 613

Re: 6809 Co Pro Client ROM

Is there anything you need me to do to change BBCBASIC for the recent changes, I've been concentrating on other stuff...
by dominicbeesley
Wed Jul 26, 2017 3:25 pm
Forum: hardware
Topic: 6809 experiments
Replies: 88
Views: 2879

Re: 6809 experiments

Oooh, I just spotted the 10 character per line mode that I'd forgotten...256 colours at a rather grainy 80x256 pixels!

I wonder, would this be possible with the VideoNuLA?

D
by dominicbeesley
Tue Jul 25, 2017 12:00 am
Forum: hardware
Topic: 6809 experiments
Replies: 88
Views: 2879

Re: 6809 experiments

I decided to have a quick experiment to see if the RAMDAC idea was a goer...it is! It takes a bit of "over driving" the IMS G171 to get it to output levels close to the Beeb's 2.5 ish volts for peak white (in its usual job as a VGA RAMDAC it only goes up to 0.7V, however nothing seems to h...
by dominicbeesley
Sun Jul 23, 2017 4:26 pm
Forum: hardware
Topic: Palettemate / enhanced video ULA with 4096 colours
Replies: 420
Views: 13053

Re: Palettemate / enhanced video ULA with 4096 colours

I'm glad you pointed out the terminal emulator thing...I'd just started work on that now I can let you do it! I'll have to think of something else to do...
by dominicbeesley
Thu Jul 20, 2017 10:27 am
Forum: software: other
Topic: cc65 C Cross Compiler
Replies: 6
Views: 363

Re: cc65 C Cross Compiler

I managed to get work I'd done copied over to a newer 2.16 version of cc65. This compiles and I've run a simple hello world program built by it but not much more. I suspect there are bugs and I seem to remember pressing Esacape caused programs to die horribly! https://github.com/dominicbeesley/cc65 ...
by dominicbeesley
Wed Jul 19, 2017 3:19 pm
Forum: software: other
Topic: cc65 C Cross Compiler
Replies: 6
Views: 363

Re: cc65 C Cross Compiler

Thanks, No I hadn't, I'll have a look!

(Though I quite liked hacking cc65 whereas gcc is just too big to be fun and quick to change, I've been trying to get gcc6809 working too...
by dominicbeesley
Wed Jul 19, 2017 2:52 pm
Forum: software: other
Topic: cc65 C Cross Compiler
Replies: 6
Views: 363

Re: cc65 C Cross Compiler

Did you get anywhere with this?

I started on a bbc target a long time ago and I was about to resurrect it and try and get it into 2.16.

D
by dominicbeesley
Wed Jul 19, 2017 12:36 pm
Forum: hardware
Topic: Palettemate / enhanced video ULA with 4096 colours
Replies: 420
Views: 13053

Re: Palettemate / enhanced video ULA with 4096 colours

Happy customer!

I received mine today. Installation was a breeze, with a socketed ULA it took a few minutes.

For those people who need to desolder and socket their ULA here's a nice video https://www.youtube.com/watch?v=Z38WsZFmq8E

Now...to write some software.

D
by dominicbeesley
Wed Jul 19, 2017 10:02 am
Forum: hardware
Topic: 6809 experiments
Replies: 88
Views: 2879

Re: 6809 experiments

Indeed, I still suspect that Motorola's decision was never so much a design decision as a matter of happenstance, like so many things. The TMS9900 chip was indeed a dog, I had for a while a TI99 with an assembler (cartridge or tape I can't remember). I though I might be able to get something interes...
by dominicbeesley
Mon Jul 17, 2017 3:43 pm
Forum: hardware
Topic: 6809 experiments
Replies: 88
Views: 2879

Re: 6809 experiments

Thanks B3, That looks like a good read, though I couldn't find any mention of endianness on my quick read through of page 6 just about 6800 source-software compatibility. That's not really a justification for endianness, rather for keeping people who are already invested in a particular architecture...
by dominicbeesley
Thu Jul 13, 2017 12:57 pm
Forum: hardware
Topic: 6809 experiments
Replies: 88
Views: 2879

Re: 6809 experiments

I'm not sure I follow you. This will be a replacement motherboard for a beeb not an add on card. Or do you mean electron form-factor, that's a possibility but I only have one (broken) Electron. I have 4 beeb cases and 2 working motherboards.... I'm trying to work out how to get 4MHz and CPU modes wo...
by dominicbeesley
Thu Jul 13, 2017 1:38 am
Forum: hardware
Topic: 6809 experiments
Replies: 88
Views: 2879

Re: 6809 experiments

I've been working on my next generation hardware and taken a break to actually start trying out my ideas in VHDL to sanity check them. It's a good thing I did as there were a few assumptions I'd made that wouldn't have worked out in the real hardware! I've decided to have two CPLDs a VIDC (which doe...
by dominicbeesley
Wed Jul 12, 2017 6:56 pm
Forum: hardware
Topic: 6809 experiments
Replies: 88
Views: 2879

Re: 6809 experiments

Yes, I suspect big-endian was a "differentiator" for Motorola (To a marketing person a differentiator sounds like a wonderful opportunity, to a programmer it's sounds like a pain in the bum!) Now, some questions on "validity" of my project. This uses quite a number of modern comp...
by dominicbeesley
Sun Jul 09, 2017 2:10 pm
Forum: hardware
Topic: BBC Micro Issue 7 board technical drawings
Replies: 2
Views: 119

Re: BBC Micro Issue 7 board technical drawings

Thanks, That's what I thought but some measurements don't come out nicely on a 0.05" grid, not in mm or 1/16"...but some do seem to come out as 0.05" grid plus 1mm offset....I suspect a 2mm routing bit was used...and I may have picked a duff place for my origin! Holes all seem to be 4...
by dominicbeesley
Sun Jul 09, 2017 12:32 pm
Forum: hardware
Topic: BBC Micro Issue 7 board technical drawings
Replies: 2
Views: 119

BBC Micro Issue 7 board technical drawings

Are there any scans of the (issue 7) bbc motherboard technical drawings? I'm starting on making my 6809 clone board and it would be handy to have something to check all my measurements against! I've had a good look and can't find anything. Oh, and does anyone know Acorn worked in inches or mm, the b...
by dominicbeesley
Sat Jul 08, 2017 11:48 pm
Forum: hardware
Topic: 6809 experiments
Replies: 88
Views: 2879

Re: 6809 experiments

It does have a 16 bit ALU yes, I'm actually using a 6309 which has a 32bit ALU. The big-endianness of the 6809 is probably its greatest drawback, for this project at least. Not so much from any quasi-religious standpoint, just that all the 6502 code is little endian. The next biggest pain is that ca...
by dominicbeesley
Sat Jul 08, 2017 7:42 pm
Forum: hardware
Topic: 5 pin din domino pcb mount sockets
Replies: 10
Views: 304

Re: 5 pin din domino pcb mount sockets

Yes I will have to turn it 90 degrees...but I'll wire it up to accommodate thay. More problematic is that I've just checked my three cables two are wired one way, one the other (all have single key plugs). This wouldn't matter on the beeb but would matter here...not the end of the world though....
by dominicbeesley
Sat Jul 08, 2017 10:18 am
Forum: hardware
Topic: 5 pin din domino pcb mount sockets
Replies: 10
Views: 304

Re: 5 pin din domino pcb mount sockets

Thanks everyone, I still haven't found any 5 pin ones but I've found some 8 pin ones which are (almost) physically compatible. These will be good as I can use 5 pins for nomal BBC signals (Tx,Rx,CTS,RTS) and the extra 4 for (DCD,DSR,DTR,RI). They are not a 100% match - the centre pin is not actually...
by dominicbeesley
Fri Jul 07, 2017 2:23 pm
Forum: hardware
Topic: Palettemate / enhanced video ULA with 4096 colours
Replies: 420
Views: 13053

Re: Palettemate / enhanced video ULA with 4096 colours

It might be better to monitor REMV/BufferRemove not INSV/BufferInsert, when COPY is /removed/ from the keyboard buffer that's when you action it. Thanks - I'll modify the code to hook into REMV instead. EDIT: Thinking about it, at what point does the character get copied? Is it before copy is remov...
by dominicbeesley
Fri Jul 07, 2017 2:08 pm
Forum: hardware
Topic: Replacing Master RTC battery pack by a supercap
Replies: 16
Views: 420

Re: Replacing Master RTC battery pack by a supercap

It's a thought...mainly for ease of porting the software and the fact that I have one in my parts box....I'll give it a look though.

D
by dominicbeesley
Fri Jul 07, 2017 10:38 am
Forum: hardware
Topic: Replacing Master RTC battery pack by a supercap
Replies: 16
Views: 420

Re: Replacing Master RTC battery pack by a supercap

Here's what I'm looking at for my next 6809 motherboard. The 146818 will be used pretty much like on the beeb but I've added a MAX807 to control the battery switchover. I'm not sure, I might add a battery connector too if the supercap proves to be too weedy I'm also looking to backup some of the ram...
by dominicbeesley
Fri Jul 07, 2017 10:25 am
Forum: hardware
Topic: Replacing Master RTC battery pack by a supercap
Replies: 16
Views: 420

Re: Replacing Master RTC battery pack by a supercap

Yes, that's what I thought with the diode...unlikely to do much. It's hard to work out what the best supercap would be: There are some big 10F, 5F ones available but they have quite high leakage currents (>30uA compared to the small draw of the 146818 which is around 50uA if I'm reading the datashee...
by dominicbeesley
Thu Jul 06, 2017 12:53 pm
Forum: hardware
Topic: Replacing Master RTC battery pack by a supercap
Replies: 16
Views: 420

Re: Replacing Master RTC battery pack by a supercap

It should be simple enough to connect one up a simple series resistor should do the trick (100 ohm or so to limit charging current) a parallel diode with the resistor might help extract the last drop out...

D
by dominicbeesley
Thu Jul 06, 2017 11:38 am
Forum: hardware
Topic: Replacing Master RTC battery pack by a supercap
Replies: 16
Views: 420

Re: Replacing Master RTC battery pack by a supercap

I've had supercaps hold settings for a few months on a TRS80 model 100 laptop, I can't remember what size cap I used. I'm planning on a supercap for my 6809 and was going to fit one to my master too. It might not hold settings as long but I distrust potentially leaky batteries I'm not sure how close...
by dominicbeesley
Wed Jul 05, 2017 11:59 pm
Forum: hardware
Topic: 5 pin din domino pcb mount sockets
Replies: 10
Views: 304

Re: 5 pin din domino pcb mount sockets

Thanks all for the replies, I should have maybe been clearer - I'm looking for a serial socket (see here: http://shalewyn.com/indexer.php?m=RetroComputing&n=Acorn&o=BBCserialcable ) Jon C - those are stero 180 degree DIN, the BBC serial port is in a 360 degree domino configuration with a pin...
by dominicbeesley
Wed Jul 05, 2017 8:05 pm
Forum: hardware
Topic: Palettemate / enhanced video ULA with 4096 colours
Replies: 420
Views: 13053

Re: Palettemate / enhanced video ULA with 4096 colours

Well done - what a result!

D
by dominicbeesley
Wed Jul 05, 2017 6:46 pm
Forum: hardware
Topic: 5 pin din domino pcb mount sockets
Replies: 10
Views: 304

5 pin din domino pcb mount sockets

I'm trying to find some of these - with little luck so far.

Does anyone know of a source for a small number (10 or so)?

Also, I'm trying to find is there a "compatible" connector but with more pins i.e. a 8 or 9 way DIN socket that would take a 5 pin plug?

D
by dominicbeesley
Wed Jul 05, 2017 10:42 am
Forum: hardware
Topic: Palettemate / enhanced video ULA with 4096 colours
Replies: 420
Views: 13053

Re: Palettemate / enhanced video ULA with 4096 colours

Are you (re)writing a new MOS or is this a utility ROM? It's a shame that the MOS doesn't call OSBYTE_135 via its vectors as then it would be simple to trap. Personally, for now, I'd vote for just getting it working without cursor editing in those modes, it might be difficult to get it working with ...
by dominicbeesley
Sat Jun 24, 2017 8:33 am
Forum: hardware
Topic: 6809 experiments
Replies: 88
Views: 2879

Re: 6809 experiments

That's pretty much it. It's easy to forget just how efficiently these things are coded when used to more modern approaches. That's my point though. A test and branch is a relatively expensive operation (five or more cyclyes) and there are quite a few places where that would need to be added. What I ...
by dominicbeesley
Sat Jun 24, 2017 12:37 am
Forum: hardware
Topic: 6809 experiments
Replies: 88
Views: 2879

Re: 6809 experiments

There is no confusion at this end. Merely a statement of the fact that it is not as simple as you propose. A lot of work would need to be done to redo the way BASIC handles evaluation, assignment, parsing. For instance, when BASIC evaluates an expression such as !&3000=23*56+200 The first thing ...

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