Search found 203 matches

by PhilYoung
Thu Nov 19, 2015 11:45 am
Forum: hardware
Topic: Beeb FPGA
Replies: 505
Views: 45574

Re: Beeb FPGA

I'm getting some quite weird results..... Slightly of topic, but it seems many of these games rely on the User 6522's T1 counter power up with a random value in the latch. The FPGA is powering up with 0 in the latch, which means the IC69 detect code in many Acornsoft games is failing 50% of the tim...
by PhilYoung
Thu Nov 19, 2015 10:36 am
Forum: hardware
Topic: Beeb FPGA
Replies: 505
Views: 45574

Re: Beeb FPGA

Model B SD functions perfectly with all cards, Problem only in Master mode. Card format error only occoursif card is incorrectly formatted, eg fat32. with card formatted to fat 16, the card is recognised and you can select discs and *cat them, it even loads the STH menu. when you try to load a game...
by PhilYoung
Wed Nov 18, 2015 7:59 pm
Forum: hardware
Topic: Beeb FPGA
Replies: 505
Views: 45574

Re: Beeb FPGA

Hi Guys, I've spent some time this afternoon improving the timings constraints, which should tighten up the timings around the SRAM Interface. They are still not perfect - it's complaining about one path, but on inspection it looks like a tool is getting confused. Anyway, here is a set of test buil...
by PhilYoung
Wed Nov 18, 2015 8:54 am
Forum: hardware
Topic: Beeb FPGA
Replies: 505
Views: 45574

Re: Beeb FPGA

Here's my plan: 1. Do the best job I can of accurately specifying input and output timings constraints for the SRAM interface in the .sdc file, which I'm not doing well at the moment. 2. Create a set of test builds that set the output drive at 4, 8, 12, 16, 20, 24mA and get both of you to quickly t...
by PhilYoung
Tue Nov 17, 2015 4:07 pm
Forum: hardware
Topic: Beeb FPGA
Replies: 505
Views: 45574

Re: Beeb FPGA

The only slight problem is that the SD card I'm using is working fine in 'BBC' mode but is giving me 'Card format?' in 'Master' mode. And I don't have an appropriate RS232 lead to try out the debugger, but I'm sure ebay can help with that, That's probably because it's FAT-32, and I don't think MMFS...
by PhilYoung
Tue Nov 17, 2015 3:02 pm
Forum: hardware
Topic: Beeb FPGA
Replies: 505
Views: 45574

Re: Beeb FPGA

Hi Phil, I've updated the released version with the above changes: https://github.com/hoglet67/BeebFpga/tree/master/altera/release It would be great if you could re-test this version, to make sure I've not messed anything up. Thanks! Dave Hi Dave, I've just tested those, both the 'sof' and 'pof' ve...
by PhilYoung
Tue Nov 17, 2015 1:38 pm
Forum: hardware
Topic: Beeb FPGA
Replies: 505
Views: 45574

Re: Beeb FPGA

Hi Phil, I don't think there is any point in your trying to get it going on this broken version of the DE1 that Terasic decided to produce, the problem seems common to several projects and the only viable solution is a RAM swap. So, assuming I can persuade you to spend a bit of time on this with me...
by PhilYoung
Tue Nov 17, 2015 1:09 pm
Forum: hardware
Topic: Beeb FPGA
Replies: 505
Views: 45574

Re: Beeb FPGA

I've tried this on my 'new/bad' SRAM' DE1, and it's the same old story I'm sad to say. It almost works, so I get a display (with some corruption) and can see the different start up screens for BBC B and Master, and the different modes for the BBC selected by the toggle switches and so on. I can ent...
by PhilYoung
Tue Nov 17, 2015 12:12 pm
Forum: hardware
Topic: Beeb FPGA
Replies: 505
Views: 45574

Re: Beeb FPGA

Any early adopters for the Altera DE1 Build? :D :D :D Dave Hi, I've tried this on my 'new/bad' SRAM' DE1, and it's the same old story I'm sad to say. It almost works, so I get a display (with some corruption) and can see the different start up screens for BBC B and Master, and the different modes f...
by PhilYoung
Mon Nov 16, 2015 10:41 am
Forum: general
Topic: Today I received.....
Replies: 5660
Views: 476606

Re: Today I received.....

Just received this from FordP: =D> =D> =D> =D> =D> =D> =D> Many thanks! The BeebFpga adventure can continue...... Looks like you have the 'good' SRAM (not xxxEDxx). Once you confirm it's working, it'll be interesting to see if it works on the 'bad' SRAM. Otherwise I'm warming up the soldering iron....
by PhilYoung
Sat Nov 14, 2015 8:41 am
Forum: acorn atom and system
Topic: ATOM FPGA
Replies: 446
Views: 55337

Re: ATOM FPGA

The suggested solutions (which I tried as far as possible) that I can remember were: ... change the output current capacity of those lines down from 20mA to 4mA - not sure if I tried this. ... This seems to be the leading candidate for fixing this, see: http://www.alteraforum.com/forum/showthread.p...
by PhilYoung
Fri Nov 13, 2015 2:42 pm
Forum: acorn atom and system
Topic: ATOM FPGA
Replies: 446
Views: 55337

Re: ATOM FPGA

So, getting to the point, it would be a good idea to check and be specific about which SRAM version DE1 is being targeted. If you can get it to work with the 'bad' SRAM then that would be ideal, it seems to work fine at lower speeds, Thanks for that head-up. BeebFPGA is currently driving the memory...
by PhilYoung
Fri Nov 13, 2015 1:06 pm
Forum: acorn atom and system
Topic: ATOM FPGA
Replies: 446
Views: 55337

Re: ATOM FPGA

One potential pitfall with the DE1 is that at some point they changed the SRAM used from IS61LV25616AL to IS61WV25616EDBLL. Although the data sheets suggest that these two have very similar timing there seems to have been a lot of difficulty getting the 'bad' later SRAM to work reliably when project...
by PhilYoung
Wed Nov 11, 2015 9:07 am
Forum: acorn atom and system
Topic: Atom Floppy
Replies: 22
Views: 3554

Re: Atom Floppy

External version for me please, I probably don't need the cable.

Have you settled on a price for this yet ? (with and without cable options would be helpful)

Cheers,

Phil Young
by PhilYoung
Thu Oct 08, 2015 8:10 am
Forum: acorn atom and system
Topic: Atom Colour & floppy board interest.
Replies: 46
Views: 4591

Re: Atom Colour & floppy board interest.

Hi,

I'd be interested in one of each board,

Cheers,

Phil Young
by PhilYoung
Fri Sep 25, 2015 9:27 am
Forum: for sale / freebies
Topic: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro
Replies: 603
Views: 74617

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

Hi,

Having seen the 'Atom Tube' implementation, can you add me to the 2nd run list for a Model B, please ?

Cheers,

Phil Young
by PhilYoung
Sat Jul 04, 2015 1:39 pm
Forum: hardware
Topic: Advice/Tips on Professional PCB Production
Replies: 13
Views: 1727

Re: Advice/Tips on Professional PCB Production

I haven’t developed any PCB's using this yet (but people on another retro computer site have, both home etched prototypes and professionally produced ), but have been using it to draw schematics. If you use Linux, it is well worth having a play. What am I taking about? Well gEDA. Wikipedia entry he...
by PhilYoung
Mon May 25, 2015 10:41 am
Forum: acorn atom and system
Topic: Atom Colour Board Thread
Replies: 236
Views: 37805

Re: Atom Colour Board Thread

Hi Phil, I think it's possible to use the MC1372 to generate baseband composite video. In the data sheet Test Circuit 2 does this. There are also a family of composite video boards for the CoCo2 that use the MC1372. See this page for more details: https://sites.google.com/site/thezippsterzone/home/...
by PhilYoung
Mon May 25, 2015 7:44 am
Forum: acorn atom and system
Topic: Atom Colour Board Thread
Replies: 236
Views: 37805

Re: Atom Colour Board Thread

On ebay: http://www.ebay.com/itm/Vintage-Acorn-ATOM-computer-will-ship-world-wide-/161713196396 This expensive Atom has a colour board I have not seen before: SVideoAdapter.PNG Can anyone identify what this is? The MC1372 is a colour modulator designed to work with the MC6847: SVideoAdapterSchemati...
by PhilYoung
Sun May 24, 2015 11:34 am
Forum: hardware
Topic: Building Rolands new Atom design...
Replies: 367
Views: 34392

Re: Building Rolands new Atom design...

It's time I attached some external hardware to my new Atom.... I need to decide whether to fit the standard DIN 41612 A+B connector, or whether to fit a latching IDC header. What's the Farnell part number for the 64 pin latching IDC plug that people (Phil and Mark I think) are using? Dave Hi, The o...
by PhilYoung
Sat May 09, 2015 11:48 am
Forum: acorn atom and system
Topic: Acorn Atom 6502 tracer
Replies: 18
Views: 2885

Re: Acorn Atom 6502 tracer

Hi,

Maybe something like this is what you're after. Seems to allow either single stepping (and display of address/data) or free running until a break address (settable) is reached.

http://www.baltissen.org/newhtm/debugger.htm

Cheers,

Phil Young
by PhilYoung
Thu Apr 09, 2015 7:39 am
Forum: hardware
Topic: Building Rolands new Atom design...
Replies: 367
Views: 34392

Re: Building Rolands new Atom design...

roland wrote:There are four 2015 models built (including Hoglets) and they all seem to work. The fifth is being build but no status info so far....
The first batch was a Friday afternoon job then.....

Cheers,

Phil Young
by PhilYoung
Wed Apr 08, 2015 9:26 pm
Forum: hardware
Topic: Building Rolands new Atom design...
Replies: 367
Views: 34392

Re: Building Rolands new Atom design...

Nice =D> However, IIRC Phil has a 2015 board, so on every five boards there is one faulty board which is 20% faulty. I think I have to find another supplier for the next batch..... How's Chuckie Egg running on your Atom? Nope, it's a 2014 version. How many of the 2015's have been built so far do yo...
by PhilYoung
Mon Mar 16, 2015 5:52 pm
Forum: acorn atom and system
Topic: Designing a new Atom main board
Replies: 668
Views: 58468

Re: Designing a new Atom main board

Hi Phil, PIC's are quite simple to program. We're using simple, plain assembly code. I'd love to see your code as we don't have anything for setting the matrix yet. And thanks for the hint about the MT8816. Greetings, Roland Hi Roland, I've attached the arduino code, the simplified PS/2 interface i...
by PhilYoung
Mon Mar 16, 2015 3:19 pm
Forum: acorn atom and system
Topic: Designing a new Atom main board
Replies: 668
Views: 58468

Re: Designing a new Atom main board

IIRC you also need an Arduino or so for your interface? Oh yes, I forgot to mention that ! I'm not suggesting it as a general solution, just what works for me. I suppose you could incorporate the ATmega168 into a stand alone design though, so a programmer would be needed. I think you can use anothe...
by PhilYoung
Mon Mar 16, 2015 10:22 am
Forum: acorn atom and system
Topic: Designing a new Atom main board
Replies: 668
Views: 58468

Re: Designing a new Atom main board

4. Not really a problem, but without tinning (which you can actually do yourself) the copper gradually tarnishes. So you get a sort of Steampunk look after a while. To keep the board looking clean, and to protect the copper use a PCB Lacquer. Available from many suppliers, here are some links: http...
by PhilYoung
Mon Mar 16, 2015 10:18 am
Forum: acorn atom and system
Topic: Designing a new Atom main board
Replies: 668
Views: 58468

Re: Designing a new Atom main board

IIRC you also need an Arduino or so for your interface? Oh yes, I forgot to mention that ! I'm not suggesting it as a general solution, just what works for me. I suppose you could incorporate the ATmega168 into a stand alone design though, so a programmer would be needed. I think you can use anothe...
by PhilYoung
Mon Mar 16, 2015 9:24 am
Forum: acorn atom and system
Topic: Designing a new Atom main board
Replies: 668
Views: 58468

Re: Designing a new Atom main board

Phil...your board looks very interesting, how would we go about building one please? TC :) Hi, Toner transfer, I was astonished at how well it works. I used parts of this system: http://www.pcbfx.com/main_site/pages/start_here/overview.html which can be seen in use here: https://www.youtube.com/wat...
by PhilYoung
Sun Mar 15, 2015 9:17 am
Forum: acorn atom and system
Topic: Designing a new Atom main board
Replies: 668
Views: 58468

Re: Designing a new Atom main board

Hi,

Here's my 8816 Arduino shield version:
8816_shield.JPG
and in situ:
8816_insitu.JPG
Apologies for the soldering on the via/wire links, I could only find a fairly blunt 0.8mm drill bit and the pads were pretty much obliterated.

Cheers,

Phil Young
by PhilYoung
Sun Feb 22, 2015 3:39 pm
Forum: hardware
Topic: Building Rolands new Atom design...
Replies: 367
Views: 34392

Re: Building Rolands new Atom design...

I haven't noticed that either. Mark must be right, a one time fault. Maybe Kees can inspect this board. I have checked the Mk2 boards but they are all right on that spot. Hi Roland, As you and Marc say it was certainly a one-off error during the board production. No harm done. I was wondering thoug...