Search found 1775 matches

by jms2
Tue Jul 18, 2017 9:07 pm
Forum: general
Topic: ADFFS on Raspberry Pi 2
Replies: 5
Views: 152

Re: ADFFS on Raspberry Pi 2

Fixed it! It was my fault - I failed to read the ADFFS instructions closely enough. You need to put the command "disable_mode_changes" into a new file called CMDLINE.TXT... not in CONFIG.TXT. Everything now seems to work fine, except I would imagine the memory stick is probably still a bit...
by jms2
Tue Jul 18, 2017 8:12 pm
Forum: general
Topic: ADFFS on Raspberry Pi 2
Replies: 5
Views: 152

Re: ADFFS on Raspberry Pi 2

I've played around with a few more settings, but have had no more success. I tried setting hdmi_group=2 and hdmi_mode=81, which should reflect the actual resolution of my TV. This didn't help. I also tried commenting out the line "ADFFS$LCDGameModes=Y", because it seems that LCDGameModes d...
by jms2
Sun Jul 16, 2017 10:23 pm
Forum: general
Topic: ADFFS on Raspberry Pi 2
Replies: 5
Views: 152

Re: ADFFS on Raspberry Pi 2

Yes, I think so, that's the 'disable_mode_change’ setting?
by jms2
Sun Jul 16, 2017 6:20 pm
Forum: general
Topic: ADFFS on Raspberry Pi 2
Replies: 5
Views: 152

Re: ADFFS on Raspberry Pi 2

A bit of progress - I tried changing the monitor type to "Other\Generic" and now I can successfully get into Modes 12 & 15. I thought this had solved the problem, but games still seem not to work.

I did try an original type Pi (using the same Risc OS image) but this didn't help.
by jms2
Sun Jul 16, 2017 11:56 am
Forum: general
Topic: ADFFS on Raspberry Pi 2
Replies: 5
Views: 152

ADFFS on Raspberry Pi 2

I've been using ADFFS for a while on real hardware, but I've noticed that all the recent releases seem to focus quite a bit on improving functionality with the Pi - so I decided to dust off the Pi and see what I've been missing. Mine is a Pi 2 connected to a digital LCD TV via HDMI. I downloaded RC1...
by jms2
Tue Jun 20, 2017 9:23 pm
Forum: hardware
Topic: Pegasus, New AP5 and New AP3/4 Painted Metal case
Replies: 18
Views: 400

Re: Pegasus, New AP5 and New AP3/4 Painted Metal case

Dave I'd like a Pegasus case, plus ideally an AP5 case. Preferably in beige. Regarding powder coating, is this necessarily the best choice? Would it be cheaper to supply them in bare metal, then people could spray paint them any colour they like? One other thing, how big is the AP5 case? I might wan...
by jms2
Thu Jun 01, 2017 9:16 pm
Forum: hardware
Topic: Upgrades to make Master out of an Electron?
Replies: 14
Views: 482

Re: Upgrades to make Master out of an Electron?

I'd always wondered how the MRB worked. There doesn't seem to be a schematic anywhere.
by jms2
Thu Jun 01, 2017 5:26 am
Forum: hardware
Topic: 80 column teletext
Replies: 24
Views: 1013

Re: 80 column teletext

That's incredible, well done!! =D>

Is there a way to integrate this into a Beeb, or is it just a very cool experiment?
by jms2
Wed May 31, 2017 7:40 pm
Forum: off-topic
Topic: Poisoning Young Minds
Replies: 14
Views: 640

Re: Poisoning Young Minds

richmond62 wrote:I chose this title for this posting because most people I meet (mainly parents of children I teach)
have a very restricted idea of what constitutes learning to program computers

That's surprising, and disappointing to hear.
What do they expect you to teach?
by jms2
Wed May 31, 2017 7:39 pm
Forum: hardware
Topic: Simple Electron flash cartridge with 39SF010 + 74HCT00
Replies: 53
Views: 1785

Re: Simple Electron flash cartridge with 39SF010 + 74HCT00

I'm curious about your intention to use all 64k of the Electron's address space as RAM. How are you planning to deal with conflicts with the existing RAM and ROM in the system? Usually the only part of the address space it's safe to use is the sideways portion (&8000-&BFFF) and some parts o...
by jms2
Wed May 31, 2017 5:15 pm
Forum: hardware
Topic: Simple Electron flash cartridge with 39SF010 + 74HCT00
Replies: 53
Views: 1785

Re: Simple Electron flash cartridge with 39SF010 + 74HCT00

One further thought on the subject of ram timings... There is quite a lot of advice about this on the web (in relation to the 6502) and everyone agrees that you have to provide some kind of gating using the clock to make sure that spurious writes don't occur. However, each person seems to have their...
by jms2
Tue May 30, 2017 12:41 pm
Forum: hardware
Topic: Simple Electron flash cartridge with 39SF010 + 74HCT00
Replies: 53
Views: 1785

Re: Simple Electron flash cartridge with 39SF010 + 74HCT00

Superb answers guys! That closes out the discrepancy between the apparent 60ns requirement and Dave H's findings that Phi0 works OK. I had gone to the trouble of superimposing screen grabs of the 6502's timing diagram and the one for the static ram chip I'm using. Whilst this was a useful exercise i...
by jms2
Mon May 29, 2017 12:45 pm
Forum: hardware
Topic: Simple Electron flash cartridge with 39SF010 + 74HCT00
Replies: 53
Views: 1785

Re: Simple Electron flash cartridge with 39SF010 + 74HCT00

One other thing, going back to RAM timings... I've been reading the posts relating to timings closely, and I note the need for the RAM to hold the data for 60ns after the end of the Phi0 high period. As you've noted, this could pose a problem if #CE is gated with Phi0, because most srams don't hold ...
by jms2
Mon May 29, 2017 8:24 am
Forum: hardware
Topic: Simple Electron flash cartridge with 39SF010 + 74HCT00
Replies: 53
Views: 1785

Re: Simple Electron flash cartridge with 39SF010 + 74HCT00

...found DesignSpark too difficult, for instance Have you totally given up with DesignSpark? I did EUP in the latter and you're welcome to the files if it would help? Hello Martin, sorry I didn't spot your post as it snuck in just ahead of myelin's. I haven't necessarily given up on Designspark (ne...
by jms2
Sun May 28, 2017 9:18 pm
Forum: hardware
Topic: Simple Electron flash cartridge with 39SF010 + 74HCT00
Replies: 53
Views: 1785

Re: Simple Electron flash cartridge with 39SF010 + 74HCT00

Thanks - that makes sense and I'm pleased that it wasn't me being incompetent!

It's nice to have two projects to examine as well.
by jms2
Sun May 28, 2017 6:14 pm
Forum: hardware
Topic: Simple Electron flash cartridge with 39SF010 + 74HCT00
Replies: 53
Views: 1785

Re: Simple Electron flash cartridge with 39SF010 + 74HCT00

Hello Myelin, I'm trying to teach myself KiCad to design an Electron expansion board; I've not got very far with it and to be honest it's far from clear whether I'm going to stay the course (found DesignSpark too difficult, for instance) but I'm giving it a try. One of the things that I thought migh...
by jms2
Sun May 28, 2017 5:55 am
Forum: software: classic games
Topic: Syncron
Replies: 4
Views: 271

Re: Syncron

Great work!

The four levels do look pretty much identical, which is a pity given how much memory they occupy.

I remember reading that Syncron is barely a game at all: Gary Partis wrote it as a tech demo. I think he sometimes appears on these forums actually.
by jms2
Fri May 12, 2017 12:46 pm
Forum: off-topic
Topic: Windows Technical Support v a BBC Master 128
Replies: 8
Views: 291

Re: Windows Technical Support v a BBC Master 128

Fantastic work!! =D> Nearly 11 minutes of their time wasted must be a record - I kept one going in a very similar vein for nearly as long once, but I have to concede victory to you. Interesting technique you used, being quite open with them that this was a BBC computer and that it doesn't "do&q...
by jms2
Sun Apr 30, 2017 7:32 pm
Forum: hardware
Topic: Electron ULA Documentation Updates
Replies: 69
Views: 2639

Re: Electron ULA Documentation Updates

OK - here's Draft 2 of Issue 3 of the Electron Advanced User Guide. I think this now includes everything that people have asked for following the review of draft 1. The headline changes compared to Issue 2 (still in red text for review purposes) are: - New cover picture to replace the bizarre compos...
by jms2
Sat Apr 29, 2017 9:30 pm
Forum: off-topic
Topic: Let's talk about serious matters
Replies: 3
Views: 178

Re: Let's talk about serious matters

OK, I tried it. First impressions are pretty good considering that this method is Not Officially Approved :wink:. This is what I did - it's not the same as what was mentioned in the article because I wasn't paying attention when I read it. #-o - Got the kettle nearly boiling, but not quite (it did s...
by jms2
Sat Apr 29, 2017 8:46 pm
Forum: off-topic
Topic: Let's talk about serious matters
Replies: 3
Views: 178

Re: Let's talk about serious matters

Interesting... never tried it, but I will give it a go.

I find that some cups of tea come out better than others, and I don't know why. If this method is more consistent then I will be pleased!
by jms2
Thu Apr 27, 2017 7:47 pm
Forum: hardware
Topic: Electron ULA Documentation Updates
Replies: 69
Views: 2639

Re: Electron ULA Documentation Updates

Thanks -- that's now included. I've got another interesting little anomaly to resolve now, which relates to the main system variables (those set by OSBYTES &A6-&FF). I'm including all the details of these from the "Allmem" file into the EAUG, excluding anything which is not relevan...
by jms2
Tue Apr 25, 2017 10:13 pm
Forum: hardware
Topic: Electron ULA Documentation Updates
Replies: 69
Views: 2639

Re: Electron ULA Documentation Updates

I have realised that I have more work to do in updating the memory map chapter, and I've been progressing that a bit today. There will be quite a lot of changes for the third edition; please keep the ULA discoveries (and other suggestions) coming! A question : what is &2F4 used for? It just says...
by jms2
Sun Apr 23, 2017 9:28 pm
Forum: hardware
Topic: Electron ULA Documentation Updates
Replies: 69
Views: 2639

Re: Electron ULA Documentation Updates

davidb wrote:That looks good to me!


Excellent, thanks for the feedback David (s)!
by jms2
Sun Apr 23, 2017 6:42 pm
Forum: hardware
Topic: Electron ULA Documentation Updates
Replies: 69
Views: 2639

Re: Electron ULA Documentation Updates

I've just checked what I did in the Electron ULA VHDL: https://github.com/hoglet67/ElectronFpga/blob/master/src/common/ElectronULA.vhd#L641 That's also suggesting the bit order is: <start bit> <bit 0> <bit 1> <bit 2> ... <bit 7> <stop bit> What exactly did I say earlier that contradicts this? I've ...
by jms2
Sun Apr 23, 2017 11:26 am
Forum: hardware
Topic: Electron ULA Documentation Updates
Replies: 69
Views: 2639

Re: Electron ULA Documentation Updates

I see what you mean about the figure, but are you sure your understanding is correct? It clashes with what hoglet said previously, and also with this remark which was present in the original AUG: "If the byte is not read within about 2ms, the data will be lost forever as bit 7 falls off the end...
by jms2
Sun Apr 23, 2017 6:40 am
Forum: hardware
Topic: Electron ULA Documentation Updates
Replies: 69
Views: 2639

Re: Electron ULA Documentation Updates

I'll have a look at that David (the figure that is, I can't promise to unravel the mysteries of the shift register!) :D Your suggestion is the prompt I needed to get on and finish this draft. It is 90% done, but I got stuck with trying to contact Chris Dewhurst over the diagrams, and since then the ...
by jms2
Sun Apr 16, 2017 6:56 am
Forum: adventures
Topic: The Darkness of Raven Wood
Replies: 60
Views: 2689

Re: The Darkness of Raven Wood

BTW, a funny thing I noticed is that the Electron seems unable to display the colour yellow (or at least, ElectrEm is). On ElectrEm, colour 3 is white, colour 7 is gray. Is this the way the Electron display works, or is it an ElectrEm bug? C. That sounds very strange! Electrons certainly can displa...
by jms2
Sat Apr 15, 2017 7:44 am
Forum: other vintage computer hardware, software and games
Topic: IBM PC XT meets the 21st Century!
Replies: 16
Views: 525

Re: IBM PC XT meets the 21st Century!

Ah, I see. I did know about PC podules but I didn't realise you could get them for the A4000, nor that they were powerful enough to run Windows.

Reading your other thread, I do have the ARMDRV.DRV file... But for the Risc PC 486 card. I don't know if it would be the same...
by jms2
Fri Apr 14, 2017 9:51 pm
Forum: other vintage computer hardware, software and games
Topic: IBM PC XT meets the 21st Century!
Replies: 16
Views: 525

Re: IBM PC XT meets the 21st Century!

How is the A4000 running Windows?

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