Search found 654 matches

by dominicbeesley
Fri Nov 16, 2018 11:12 pm
Forum: hardware
Topic: SpectROM - Speccy emulator for the Pi co-pro
Replies: 181
Views: 9222

Re: SpectROM - Speccy emulator for the Pi co-pro

A quick n dirty hack might be to capture both IRQ1V and IRQ2V: at the end of your IRQ1V clear the VA1/vsync bit in the IER and then reenable it in IRQ2V that would stop the mos from considering it?

D
by dominicbeesley
Fri Nov 16, 2018 10:40 pm
Forum: hardware
Topic: A blitter for the beeb?
Replies: 67
Views: 5773

Re: A blitter for the beeb?

Thanks all, mlouka, I'll look at those suggestions - do they use GXR extensions do you know? RobC, thanks! I looked at standard Model B Elite IIRC - I have some sources somewhere but couldn't make much of them with the brief look over I gave them. The Tube one probably is easier. I'll have a look at...
by dominicbeesley
Fri Nov 16, 2018 10:26 pm
Forum: hardware
Topic: SpectROM - Speccy emulator for the Pi co-pro
Replies: 181
Views: 9222

Re: SpectROM - Speccy emulator for the Pi co-pro

Hi Rob, I've had this problem myself, it doesn't matter which vector you hang off i.e. IRQ1V is called before the mos routines there's always the chance that the relevant bit in the interrupt flags register could get set between your routine and the mos one and then the mos code would handle it. How...
by dominicbeesley
Thu Nov 15, 2018 12:28 pm
Forum: hardware
Topic: A blitter for the beeb?
Replies: 67
Views: 5773

Re: A blitter for the beeb?

It doesn't just do horizontal and vertical

Acceleration off:
20181115_122320-s.jpg
Acceleration on:
20181115_122336-s.jpg
Does anyone know of any vector graphics based games that might benefit that would be reasonably simple to hack - I looked at Elite and it was a bit over-facing...
by dominicbeesley
Thu Nov 15, 2018 12:24 am
Forum: hardware
Topic: A blitter for the beeb?
Replies: 67
Views: 5773

Re: A blitter for the beeb?

I had some time on this project last weekend when I had a couple of hours free...I've got simple accelerated line drawing working! The small test assembler program I've been using as the benchmark draws a few spirals on screen - this takes 10-13 seconds on an un-accelerated Model B depending on scre...
by dominicbeesley
Wed Nov 14, 2018 11:40 am
Forum: hardware
Topic: Logic Levels for 5V TTL Systems
Replies: 10
Views: 383

Re: Logic Levels for 5V TTL Systems

I know, its just another thing that needs to go on the list of gotchas with logic levels, along with the "compatible" LVCMOS and LVTTL levels popular on some FPGAs. On the 65* NMOS processors it is fall time rather than rise time that's the killer, the original 6502 could tolerate (and generated) sl...
by dominicbeesley
Wed Nov 14, 2018 10:04 am
Forum: hardware
Topic: Logic Levels for 5V TTL Systems
Replies: 10
Views: 383

Re: Logic Levels for 5V TTL Systems

And there's LVTTL levels which will drive 5v TTL parts but not CMOS... that's got me a few times. The 65816 and 65c02 chips need strong CMOS levels on their clock pins or they misbehave. I spent months debugging a problem on my first 65816 project that appeared to be a timing problem but was cured b...
by dominicbeesley
Mon Oct 29, 2018 11:52 am
Forum: hardware
Topic: Raspberry Pi to 1MHz bus interface
Replies: 22
Views: 728

Re: Raspberry Pi to 1MHz bus interface

One for me please too...
by dominicbeesley
Thu Oct 25, 2018 12:51 am
Forum: programming
Topic: cc65
Replies: 17
Views: 493

Re: cc65

I'm not so sure it's just the number of bits. C could be generated for the Z80 or 6809 more efficiently and runs ok on 8 bit PICs. The main problem with the 6502 is the small hardware stack and the hoops that have to be gone through to deal with that - maintaining a separate (manually managed) data/...
by dominicbeesley
Tue Oct 23, 2018 2:43 pm
Forum: programming
Topic: cc65
Replies: 17
Views: 493

Re: cc65

Looks interesting! If you got rid of all the printf/sprintfs you should be able to save a fair chunk of space (it looks like the main features of (s)printf they use is decimal/hex/octal printing which can be done pretty succinctly with your own functions or maybe calling the internal clib functions ...
by dominicbeesley
Tue Oct 23, 2018 12:06 pm
Forum: programming
Topic: cc65
Replies: 17
Views: 493

Re: cc65

I've no idea, it was over 10 years ago, I was probably leaving rooms for "something" though what that something was I can't remember.
by dominicbeesley
Tue Oct 23, 2018 10:04 am
Forum: programming
Topic: cc65
Replies: 17
Views: 493

Re: cc65

I think the .cfg file that is included in the source is as below, This layout uses most of the BBC's main memory - but not SWRAM/ROM....I never got round to that. Most notably it requires that you use mode 7! You could squeeze a bit more out by changing __HIMEM__ to 7C00. Also, note that the default...
by dominicbeesley
Sun Oct 21, 2018 10:04 pm
Forum: programming
Topic: cc65
Replies: 17
Views: 493

Re: cc65

That looks like you're trying to do an array of structs. In which case, each item needs curly brackets round it as well as the outer ones . I'd tore an example but I'm replying on my phone.
by dominicbeesley
Sat Oct 20, 2018 10:36 am
Forum: software: other
Topic: MOS ROM information / guids
Replies: 26
Views: 2353

Re: MOS ROM information / guids

Yes thanks. I didn't get far with it. I've been regression testing the fpga changes i made for the 65c02 with the 6309. That had led to a fair bit of fixing and re writing. Also, id done less on the 6502 mos than id thought. Im ready to put a load of IFs in thd 6809 version to compile without CFS wh...
by dominicbeesley
Sat Oct 13, 2018 10:10 am
Forum: acorn atom and system
Topic: System 6809 card...
Replies: 5
Views: 293

Re: System 6809 card...

Bbc basic with assembler. Its unfinished and would need tweaking for whatever monitor youre using though if you get flex working it should work out of the box but only with basic load/save. Pm me if you're interested
by dominicbeesley
Wed Oct 10, 2018 2:01 pm
Forum: hardware
Topic: SCSI / SCSI II adapaters?
Replies: 11
Views: 643

Re: SCSI / SCSI II adapaters?

Thanks for the info BM, I'll try ADT later tonight, though I will need to work out how to get it onto the Master, I seem to have mislaid the datacentre and MMCs during the house move. Good call on the SCSI1 switch in the mode select on some drives does seem to work. I thought of that myself but coul...
by dominicbeesley
Tue Oct 09, 2018 11:34 am
Forum: hardware
Topic: 65c02 in a Model B
Replies: 13
Views: 640

Re: 65c02 in a Model B

Interesting, I'll have to have another look at that then! I've still not got round to the accelerated mode for my project. Having the clocks asynchronous might be the key. At the moment probably 3/4 of the glue vhdl is dealing with the fact that the local 48Mhz clock and the system phi0/2 are asynch...
by dominicbeesley
Tue Oct 09, 2018 12:04 am
Forum: hardware
Topic: SCSI / SCSI II adapaters?
Replies: 11
Views: 643

Re: SCSI / SCSI II adapaters?

A quick update on this. I now have this *working* but not finished. Hard disk read/write accesses are working. I don't seem to be able to get the floppy format working but I suspect that that is a separate machine issue, possibly timing issues caused by my running this on a 65c02 in a model B Things...
by dominicbeesley
Mon Oct 08, 2018 11:55 pm
Forum: hardware
Topic: 65c02 in a Model B
Replies: 13
Views: 640

Re: 65c02 in a Model B

Yes, in principle, revaldinho had in mind that the clock could be asynchronous to the host. But in practice, that didn't seem to work quite so well (AFAICR) so a bit of revisiting of the clock domain crossings and synchronisings might be in order. Or, possibly, the phase relationship of the 16MHz w...
by dominicbeesley
Mon Oct 08, 2018 11:53 pm
Forum: software: other
Topic: cc65 C Cross Compiler
Replies: 28
Views: 2768

Re: cc65 C Cross Compiler

With all the other stuff I'm doing I doubt I'll get round to this any time soon!

If you wanted to have a go yourself it may be easier to compare my version with the version it was forked from, create diffs and try applying them to a more up-to-date version of cc65...

D
by dominicbeesley
Mon Oct 08, 2018 11:51 pm
Forum: software: other
Topic: MOS ROM information / guids
Replies: 26
Views: 2353

Re: MOS ROM information / guids

I've looked at my 6502 sources and they're nowhere near finished but I'm loathe to abandon them altogether in favour of either of your two flavours as, even though mine are highly idiosyncratic, the idiosyncrasies match those in my 6809 sources. [ the main problems with my sources at present are tha...
by dominicbeesley
Wed Oct 03, 2018 4:46 pm
Forum: software: other
Topic: MOS ROM information / guids
Replies: 26
Views: 2353

Re: MOS ROM information / guids

If people are actively working on this i can spend some time back porting some of the work i did on my 6809 port. That is an almost complete port of 1.20 with most of the labels correct and most importantly all the tables containing addresses sorted out such that stuff can be moved around. I've de-f...
by dominicbeesley
Tue Oct 02, 2018 2:24 pm
Forum: software: other
Topic: MOS ROM information / guids
Replies: 26
Views: 2353

Re: MOS ROM information / guids

Complete no, but i do have buildable sources for os 1.20

Are you interested in hacking for 6502, 65c02 or 65816?

Ill have a look when i get back. I'm on "holiday" in Jersey...looking after the bairn while other half is at work.... <> holiday....
by dominicbeesley
Tue Oct 02, 2018 2:21 pm
Forum: hardware
Topic: 65c02 in a Model B
Replies: 13
Views: 640

Re: 65c02 in a Model B

Thanks both. Coeus, yes, i had seen that. I've got the chip working reliably... it's been seeing a few hours of duty each day. It was more a question of how much software would be affected. Rtw, thanks that's a start. I wondered (hoped) if there was a list of software that didn't work on a cmos part...
by dominicbeesley
Mon Oct 01, 2018 12:47 pm
Forum: hardware
Topic: 65c02 in a Model B
Replies: 13
Views: 640

65c02 in a Model B

Hello, On my blitter board I've been using a W65C02 in place of the 6502A for some time. So far I've not run into many difficulties*, i.e. most software runs ok. Is there a list anywhere of stuff that _won't_ work on a cmos part? i.e. stuff that uses illegal ops? I'm half tempted to just say with th...
by dominicbeesley
Sun Sep 30, 2018 8:43 pm
Forum: hardware
Topic: My first (large) CPLD steps (XC9572)
Replies: 16
Views: 615

Re: My first (large) CPLD steps (XC9572)

With a few more caps close to the chip and after any jumper which could be inductive enought to introduce problems
by dominicbeesley
Wed Sep 26, 2018 4:20 pm
Forum: software: other
Topic: cc65 C Cross Compiler
Replies: 28
Views: 2768

Re: cc65 C Cross Compiler

See https://github.com/dominicbeesley/cc65 as mentioned above, its incomplete but can be used to build real programs
by dominicbeesley
Mon Sep 24, 2018 10:28 am
Forum: hardware
Topic: Beeb FPGA
Replies: 495
Views: 36851

Re: Beeb FPGA

What speed is the SRAM running at. I'd have to have a proper dig through my archive but my implementation of a BBC on an FPGA used SDRAM on the DE0 nano. I think I had it running at 8MHz, I can't remember what speed though. It was certainly servicing the memory requests at 4MHz (the speed the beeb's...
by dominicbeesley
Wed Sep 19, 2018 12:22 pm
Forum: development tools
Topic: beebasm symbols table
Replies: 2
Views: 155

Re: beebasm symbols table

I'm not sure my change does that - I'll check and make sure it does.

It looks like its useful to you then it is probably more widely useful so I'll spend some time making it a proper option(s).

Any objections to the

Code: Select all

cout << "SYMBOLS = ";
before the symbols dump?

D