Search found 955 matches

by fordp
Thu May 17, 2018 4:55 pm
Forum: hardware
Topic: Pi-based Co-Pro on the cheap - 100MHz 6502 for £10? (now 274MHz)
Replies: 1066
Views: 94267

Re: Pi-based Co-Pro on the cheap - 100MHz 6502 for £10? (now 274MHz)

hoglet wrote: - Added a new PDP-11 Co Processor (in slot 11)
Dave
Great to see a new version and PDP-11 support too.

Is the PDP "core" from elsewhere or new?
by fordp
Wed May 16, 2018 11:19 am
Forum: hardware
Topic: Pi Zero Super Interface
Replies: 23
Views: 1494

Re: Pi Zero Super Interface

https://www.hackster.io/8bitkick/bbc-micro-online-38d004?utm_campaign=new_projects_default&utm_content=1&utm_medium=email&utm_source=hackster&utm_term=project_name More interesting reading if only the Pi Zero W wireless was useable from bare metal then something like the above link could be done ov...
by fordp
Tue Apr 17, 2018 2:35 pm
Forum: for sale / freebies
Topic: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro
Replies: 603
Views: 61312

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

I have a spare one if anybody really wants one. I will be rubbish at posting it out however as I work full time.
by fordp
Thu Apr 05, 2018 12:27 pm
Forum: hardware
Topic: Pi-based Co-Pro on the cheap - 100MHz 6502 for £10? (now 274MHz)
Replies: 1066
Views: 94267

Re: Pi-based Co-Pro on the cheap - 100MHz 6502 for £10? (now 274MHz)

I just saw this Bare Metal serial terminal project and thought it may be of use as a base for an acorn project (including alongside the Pi Copro):

https://github.com/fbergama/pigfx
by fordp
Wed Apr 04, 2018 1:29 pm
Forum: hardware
Topic: Scope recommendations
Replies: 16
Views: 931

Re: Scope recommendations

I have a Hantek MSO5102D which has a good spec for the cash. It is by no means up to professional standard ones I use at work but I only use it every now and then!
by fordp
Fri Mar 30, 2018 8:05 pm
Forum: hardware
Topic: BBC Micro MMC Card adapter - compatible cards
Replies: 20
Views: 787

Re: BBC Micro MMC Card adapter - compatible cards

That is the faster version of TurboMMC by Steve Picton if I am not mistaken!

I have a slower version of TurboMMC which is un-buffered so slower.

You can also use the more open MMFS ROM with it too.
by fordp
Mon Mar 12, 2018 1:03 pm
Forum: hardware
Topic: Pi Zero Super Interface
Replies: 23
Views: 1494

Re: Pi Zero Super Interface

dp11 wrote:I've seen it before. What I'd like to do is if I get time is a 1MHz bus version of pitubedirect interface giving a hard drive and music 5000 emulator all on a pizero. I've done some of the basic thinking about this.
This quote should be on this thread ;)
by fordp
Thu Mar 08, 2018 8:18 am
Forum: other vintage computer hardware, software and games
Topic: No more leaded solder
Replies: 51
Views: 2020

Re: No more leaded solder

tricky wrote:Are you going to any ABug meetups any time soon or RISCOS shows?
No but I could send you some to distribute if you like?
by fordp
Wed Mar 07, 2018 11:14 pm
Forum: other vintage computer hardware, software and games
Topic: No more leaded solder
Replies: 51
Views: 2020

Re: No more leaded solder

I know where I can get my hands on lots of old stock if people need it. Expensive to post Royal Mail however :(
by fordp
Mon Mar 05, 2018 1:00 pm
Forum: other vintage computer hardware, software and games
Topic: ZX Spectrum next... Anybody backing ?
Replies: 109
Views: 8409

Re: ZX Spectrum next... Anybody backing ?

Hmm. This sort of thing makes me realise many people experience retrocomputing in a completely different way from me. It's cool to play with old hardware. It's cool to run old software. That game looks reasonably fun. But aren't they just running a modern game on modern hardware? Since when was a Z...
by fordp
Fri Mar 02, 2018 8:29 pm
Forum: hardware
Topic: Pi Zero Super Interface
Replies: 23
Views: 1494

Re: Pi Zero Super Interface

It is much cheaper and will fit under the BBC Micro. It has plenty of performance.
by fordp
Tue Feb 27, 2018 8:03 pm
Forum: hardware
Topic: Pi Zero Super Interface
Replies: 23
Views: 1494

Re: Pi Zero Super Interface

mph1708 wrote: Perhaps:- 5) A Network interface ? (Ethernet / WiFi)
Indeed, I mentioned Wifi before but we could not find a suitable bare metal Wifi driver. It would be lot of work without a working example.
by fordp
Thu Feb 22, 2018 7:59 am
Forum: hardware
Topic: Pi Zero Super Interface
Replies: 23
Views: 1494

Re: Pi Zero Super Interface

Now that Pi Zero is both available and affordable, a two-pi system is perhaps worth considering. Well that would always be an option. A lot of the fun of the CoPro's is writing your own code on a CoPro of your choice and I think a 1MHz bus CoPro would not be much of a hindrance to doing that. I gue...
by fordp
Wed Feb 21, 2018 1:41 pm
Forum: hardware
Topic: Pi Zero Super Interface
Replies: 23
Views: 1494

Pi Zero Super Interface

I have asked before if with some tweaks a second processor could be run on the 1MHz bus. I think the answer was yes but at 1MHz instead of 2MHz ? It occurred to me that a Pi Zero attached (via level shifters) to the 1MHz bus could be: 1) A Second Processor 2) An MMFS device 3) A SCSI Harddrive ADFS ...
by fordp
Mon Feb 19, 2018 1:51 pm
Forum: off-topic
Topic: Why did CISC prevail?
Replies: 21
Views: 1047

Re: Why did CISC prevail?

hence the Thumb instruction set The Thumb instruction set is a major bugbear of mine. I could rant a lot about it, but shall restrain myself. The one broad point I'll make is that if you look at it carefully and think about what's really going on, you'll likely spot that the technical advantages we...
by fordp
Thu Feb 15, 2018 7:53 pm
Forum: hardware
Topic: Memory for 80286 second processor
Replies: 15
Views: 614

Re: Memory for 80286 second processor

25MHz parts seem to be the fastest but they are PLCC I think.
by fordp
Thu Feb 15, 2018 12:55 pm
Forum: hardware
Topic: Memory for 80286 second processor
Replies: 15
Views: 614

Re: Memory for 80286 second processor

Looks like the faster 120ns parts are actually cheaper on that site and will probably work fine.

You could maybe overclock it the board too.
by fordp
Wed Feb 14, 2018 12:54 pm
Forum: hardware
Topic: Mega Games Cartridge (MGC) MK II Hardware Development
Replies: 30
Views: 1489

Re: Mega Games Cartridge (MGC) MK II Development

This idea behind the Cartridge is No Access - Designed with children in mind and non technical users - So, yes you'd have to open the cartridge to access the SD Card. Dave H :D If the case is going to be 3D Printed then I suggest the MicroSD cards are placed on the PCB such that one of two case des...
by fordp
Fri Feb 09, 2018 1:07 pm
Forum: hardware
Topic: BBC controlled CD Jukebox, great find but need the space!
Replies: 49
Views: 3781

Re: BBC controlled CD Jukebox, great find but need the space!

Coeus wrote:So is this, by any chance, the reason Master motherboards seem more common on eBay that complete masters?
My master motherboard came from some sort of medical scanner :wink:
by fordp
Thu Feb 08, 2018 7:55 am
Forum: off-topic
Topic: Why did CISC prevail?
Replies: 21
Views: 1047

Re: Why did CISC prevail?

When designing the ARM Steve Furber was saying how the other processors of the day could not effectively use the available memory bandwidth and this was part of the rationale for simpler, faster instructions, i.e. RISC. RISC took off - all the Unix workstation manufacturers went for it, it was only...
by fordp
Tue Feb 06, 2018 8:23 am
Forum: hardware
Topic: Open Source Logic Analyzer Experiments
Replies: 147
Views: 10051

Re: Open Source Logic Analyzer Experiments

Seems like a plan, I do occasionally need to find out what went wrong on hardware that isn't reproducible on an emulator and this seems like one way of debugging really nasty timing issues. I also have a few beebs that need looking at, which will also be easier with this. This set-up with your ROM ...
by fordp
Sun Feb 04, 2018 11:48 am
Forum: hardware
Topic: Myelin's FX2 Tube/Cartridge Adapter - Development and Support
Replies: 46
Views: 2233

Re: Myelin's FX2 Tube/Cartridge Adapter - Development and Support

It's a pity that SYNC doesn't go through the CPLD, because it would be really easy to just latch it on the rising edge of the clock! Maybe I should have just started off with a 64-pin xc9572xl after all :) I don't suppose it's possible to configure the FX2 to sample on both edges of the clock, is i...
by fordp
Thu Feb 01, 2018 9:28 pm
Forum: wanted
Topic: Lx9pro fpga copro
Replies: 23
Views: 1052

Re: Lx9pro fpga copro

RobC wrote:
fordp wrote:Can it run PDP Basic ?
Do you mean this?

If so, yes.
Cool. I am guessing you do it via the Native Copro however?
by fordp
Thu Feb 01, 2018 9:22 am
Forum: wanted
Topic: Lx9pro fpga copro
Replies: 23
Views: 1052

Re: Lx9pro fpga copro

RobC wrote:For those without a Matchbox, I do have a PDP-11 emulator running in software on the native ARM core of the Pi-copro. It'll run a few variants of UNIX (albeit a bit slowly).
Can it run PDP Basic ?
by fordp
Tue Jan 30, 2018 1:23 pm
Forum: emulators
Topic: Keyboard Stickers
Replies: 2
Views: 353

Re: Keyboard Stickers

If they are reverse printed then they would be very durable. They are selling the sets for less than $10. If you have a spare black PC keyboard lying round I think it would be a good option.

I would guess they would fit on the cherry key caps for those wanting to make a brand new Atom keyboard too.
by fordp
Tue Jan 30, 2018 8:02 am
Forum: hardware
Topic: Electron 6502 desolder / socket pics + Max 10 FPGA in CPU socket
Replies: 34
Views: 1884

Re: Electron 6502 desolder / socket pics

When I was much much younger, I wrote to Slogger to suggest that they take the Electron mainboard out of it's case and give it a bigger one (a bit like the master compact), leaving the Keyboard where it was. Maybe someone could do this as their next project giving you highrise options for your CPU ...
by fordp
Mon Jan 29, 2018 12:54 pm
Forum: emulators
Topic: Keyboard Stickers
Replies: 2
Views: 353

Keyboard Stickers

I just noticed this from a Spectrum post on Facebook: http://www.4keyboard.com/commodore/647-3006-sinclair-zx-spectrum-non-transparent-keyboard-stickers.html#/21-size_key-11x13/32-background_color-black spectrum_overlay.jpg Maybe there would be interest in designing/ ordering something similar for A...
by fordp
Mon Jan 29, 2018 9:47 am
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 209
Views: 7532

Re: RGB to HDMI using a Pi Zero and a small CPLD

It would be great to try this on my Beeb FPGA DE1, without the need for a CPLD ;)
by fordp
Thu Jan 25, 2018 9:02 am
Forum: hardware
Topic: Beeb FPGA
Replies: 488
Views: 33874

Re: Beeb FPGA

My TV works at both TV and VGA rates through the VGA input. I then use the Scart input for my real Beebs.
by fordp
Sat Jan 20, 2018 8:41 pm
Forum: hardware
Topic: Myelin's FX2 Tube/Cartridge Adapter - Development and Support
Replies: 46
Views: 2233

Re: Myelin's FX2 Tube/Cartridge Adapter - Development and Support

My board arrived, many thanks. My colleague has fitted all the small SMT components but commented there was no legend to say which round the diode should go. He was about to fit the CPLD when he realised I had got the 64pin QFP version instead of the 44 pin QFP, Doh! I will order some more chips and...