Search found 1086 matches

by IanS
Tue Jan 28, 2020 12:40 pm
Forum: hardware
Topic: A3020 Missing sigle color out of RGB
Replies: 3
Views: 43

Re: A3020 Missing sigle color out of RGB

The TRM diagrams have the video circuitry - http://chrisacorns.computinghistory.org ... awings.zip
(Across the middle of sheet 2)
by IanS
Wed Jan 22, 2020 9:45 pm
Forum: software
Topic: OS_PlatformFeatures 34 not aware of CBZ & CBNZ ?
Replies: 3
Views: 232

Re: OS_PlatformFeatures 34 not aware of CBZ & CBNZ ?

Aren't they Thumb instructions?

"information about Thumb modes is not reported"
by IanS
Tue Jan 21, 2020 11:22 am
Forum: off-topic
Topic: Replacing laptop screen
Replies: 3
Views: 141

Re: Replacing laptop screen

Looks like the bar should lift up to help disconnect the connector.
https://docs.rs-online.com/62da/0900766b80ec91c6.pdf
(Search for i-pex connector)
by IanS
Sun Jan 19, 2020 10:07 pm
Forum: for sale / freebies
Topic: FS: 8-bit IDE podules (A3010/A3020/A4000/A3000) - Out of Stock
Replies: 31
Views: 2669

Re: FS: 8-bit IDE podules (A3010/A3020/A4000/A3000)

Hi Ian, I’d love one of these for my a3010. I know it says to PM you but I can’t until I have posted 25 messages and I don’t want to make unnecessary posts 😀. I'm unfortunately out of stock at the moment, but will get some more made up after the Abug meeting next weekend (all current stock is alloc...
by IanS
Sun Jan 19, 2020 9:51 pm
Forum: hardware
Topic: Who is Bob, and why is his name on my Iss7 board?
Replies: 4
Views: 301

Re: Who is Bob, and why is his name on my Iss7 board?

NealC wrote:
Sun Jan 19, 2020 9:22 pm
On removing IC1 for testing, I find the mysterious phrase 'Bob's Board' on the silkscreen (photo attached for proof!).
https://youtu.be/fww2qkKbQ4Y?t=2206
by IanS
Sat Jan 18, 2020 6:24 pm
Forum: for sale / freebies
Topic: FS: 8-bit IDE podules (A3010/A3020/A4000/A3000) - Out of Stock
Replies: 31
Views: 2669

Re: FS: 8-bit IDE podules (A3010/A3020/A4000/A3000)

sbadger wrote:
Sat Jan 18, 2020 5:50 pm
Can I get two to collect at ABUG please with DOM?
Sure, no problem.
by IanS
Mon Jan 13, 2020 7:59 pm
Forum: hardware
Topic: Open source A3020 RAM
Replies: 49
Views: 2274

Re: Open source A3020 RAM

IanS wrote:
Mon Jan 13, 2020 6:44 pm
Make it in-circuit programmable?
Not sure this is possible. To re-program the outputs you have to disable all the outputs. And the power-up state is only One-time programmable. Still a potentially useful device, but not as good as it could be for this application.
by IanS
Mon Jan 13, 2020 7:36 pm
Forum: software
Topic: RISC OS 3.20
Replies: 2
Views: 401

Re: RISC OS 3.20

I've been out of for a while, as Matt Glover will attest to!, but where is the RISC OS 3.20 project now? The last I read physical ROMs were on the verge of being flashed! Are there any software ROMs for emu use around? Again I apologise for the spoon-feeding, but it's been a bad 24 months. I don't ...
by IanS
Mon Jan 13, 2020 7:30 pm
Forum: hardware
Topic: Econet podule for RISCPC & A7000
Replies: 87
Views: 15134

Re: Econet podule for RISCPC & A7000

If you were willing to share the schematic, or even the board layout (with me confidentially or publicly), I could make any changes you were thinking of to 'polish' it, and share an updated board back to you? Obviously I would fully credit you. Or, I could simply make a few more of your exact board...
by IanS
Mon Jan 13, 2020 7:08 pm
Forum: for sale / freebies
Topic: For Sale: A3020/A4000 & A5000 overclockable RAM
Replies: 5
Views: 432

Re: A3020/A4000 & A5000 overclockable RAM

Can you put me down for an A4000 one. I already have a 4MB upgrade, but might have a go at the overclock.
Thanks.
by IanS
Mon Jan 13, 2020 7:05 pm
Forum: hardware
Topic: Open source A3020 RAM
Replies: 49
Views: 2274

Re: Open source A3020 RAM

cmorley wrote:
Mon Jan 13, 2020 7:01 pm
That might be a handy widget Ian. Were you thinking of making one? I might tack some clock generators and crystals onto my next Mouser order and make one if not...
It's not high on my priority list, so go for it. I always thought they would make a good solution for VIDC enhancers.
by IanS
Mon Jan 13, 2020 6:44 pm
Forum: hardware
Topic: Open source A3020 RAM
Replies: 49
Views: 2274

Re: Open source A3020 RAM

72MHz - I wonder if you could just link the video oscillator over to the CPU clock input?! I looked on mouser and digikey and the DIP type oscillators are not easy to buy anymore. Would a solution based on the Si5351 be a possible? https://www.silabs.com/documents/public/data-sheets/Si5351-B.pdf Wo...
by IanS
Sun Jan 12, 2020 8:23 pm
Forum: hardware
Topic: A540 Help needed
Replies: 11
Views: 450

Re: A540 Help needed

Trisomie21 wrote:
Sun Jan 12, 2020 8:21 pm
This is the socket before it got removed.
Did the chip clean up ok? Do you have anything else you can test it in?
by IanS
Sat Jan 11, 2020 11:35 am
Forum: hardware
Topic: Acorn ROM/RAM Podule Manager
Replies: 10
Views: 314

Re: Acorn ROM/RAM Podule Manager

Investigations continue since I think there's more to the PAL though, since D0 also seems to be connected into the PAL (and LA10 -- but I suspect that might be used to buffer it), and there's also the SDE signal which feeds the 74HCT138. I could probably do some monitoring with a logic analyzer if ...
by IanS
Sat Jan 11, 2020 11:29 am
Forum: hardware
Topic: Econet podule for RISCPC & A7000
Replies: 87
Views: 15134

Re: Econet podule for RISCPC & A7000

Just wondering, it's been a long time since you posted it, did you 'finish' your Econet podule? Is it something that you're going to release in any form, be it as a product or open source the designs? Or did you already do that somewhere? I had been reading through this thread, and inspired by the ...
by IanS
Fri Jan 10, 2020 10:38 pm
Forum: hardware
Topic: Acorn ROM/RAM Podule Manager
Replies: 10
Views: 314

Re: Acorn ROM/RAM Podule Manager

Just trying to reverse engineer how the podule maps the ROM's into the podule address space at the moment, other than that it looks reasonably straight-forward. Have you seen the circuit diagram on the last page of the Acorn manual? (my ROM image was from the Acorn version). http://chrisacorns.comp...
by IanS
Fri Jan 10, 2020 8:13 pm
Forum: general
Topic: Today I received.....
Replies: 5613
Views: 468041

Re: Today I received.....

Well, almost three years later, I've finally obtained a case, keyboard and PSU for the motherboard -- just need to find out how much damage the battery did (I neutralised it three years ago, but a couple of the inductors for the mouse port have snapped off) and put it all back together. I also need...
by IanS
Thu Jan 09, 2020 9:22 pm
Forum: hardware
Topic: Acorn ROM/RAM Podule Manager
Replies: 10
Views: 314

Re: Acorn ROM/RAM Podule Manager

SteveBagley wrote:
Thu Jan 09, 2020 8:42 pm
Does anyone know if there is a dump of the Manager ROM found on Acorn's (or Computer Concepts) ROM/RAM podule available online or is anyone able to make one?
This ok?
by IanS
Sat Jan 04, 2020 9:36 pm
Forum: hardware
Topic: 3D printing podule - looking for HW & SW collaborators.
Replies: 4
Views: 239

Re: 3D printing podule - looking for HW & SW collaborators.

Does anyone have any somewhat fresh experience with interfacing to the podule bus, who could help me get oriented and into the fun part of making a new PCB layout? Hardware wise, to function it only really needs to be able to provide a single serial port to be viable. Theo's podule interfacing arti...
by IanS
Thu Jan 02, 2020 8:46 pm
Forum: hardware
Topic: A540 Help needed
Replies: 11
Views: 450

Re: A540 Help needed

I got the A540 in a non working condition, so I dont know of the IOC is still working. Is there a way to test it or just in this machine or in an other Archimedes? Thank you for the links for the technical documents. How to find the brocken tracks? Just doing an continuity test? The IOC should work...
by IanS
Wed Jan 01, 2020 9:04 pm
Forum: hardware
Topic: A540 Help needed
Replies: 11
Views: 450

Re: A540 Help needed

IC 58 is the IOC.

All details are in the TRM diagrams.

http://chrisacorns.computinghistory.org ... s.html#TRM
http://chrisacorns.computinghistory.org ... awings.zip (IOC is on page 3)

Is the chip still ok?
by IanS
Wed Dec 25, 2019 4:39 pm
Forum: hardware
Topic: A4000 strange io problem
Replies: 9
Views: 298

Re: A4000 strange io problem

Jaydr wrote:
Wed Dec 25, 2019 1:51 pm
I've noticed you can read the drive into an image file, but is the a way to access it with some sort of file explorer?
You could use Arculator to mount the image and HostFS to read/write files from the host.
viewtopic.php?f=30&t=18223
by IanS
Thu Dec 19, 2019 8:55 am
Forum: general
Topic: Today I received.....
Replies: 5613
Views: 468041

Re: Today I received.....

Leew wrote:
Thu Dec 19, 2019 8:52 am
JudgeBeeb wrote:
Wed Dec 18, 2019 11:09 pm
IMG_0714.jpeg

IMG_0719.jpeg
I've been looking for an Atom board myself. Do you have the link to where you got yours?
They are new recreations - viewtopic.php?p=254228#p254228
by IanS
Thu Dec 19, 2019 12:18 am
Forum: general
Topic: Today I received.....
Replies: 5613
Views: 468041

Re: Today I received.....

JudgeBeeb wrote:
Wed Dec 18, 2019 11:09 pm
IMG_0714.jpeg

IMG_0719.jpeg
Looks lovely. How well do the switches fit?
by IanS
Sun Dec 15, 2019 1:15 pm
Forum: upcoming and recent events & exhibitions
Topic: ABUG SOUTH 24 to 26 January 2020: NOW FULL
Replies: 171
Views: 6280

Re: ABUG SOUTH 24 to 26 January 2020 (Hampshire) BOOKING THREAD

At the end of the last ABUG, there were a considerable number of snacks left over. I had indicated at the time that I would keep these and bring them to the next ABUG. For various reasons, I now realise that is likely to prove impractical. I have therefore estimated the value of left over snacks at...
by IanS
Thu Dec 12, 2019 5:35 pm
Forum: for sale / freebies
Topic: FS: 8-bit IDE podules (A3010/A3020/A4000/A3000) - Out of Stock
Replies: 31
Views: 2669

Re: FS: 8-bit IDE podules (A3010/A3020/A4000/A3000)

markdryan wrote:
Thu Dec 12, 2019 1:15 pm
I’ll take one of the 8 bit podules with a Dom for my a3000. If it’s okay with you, I’ll pick it up and pay for it at abug in January.
No problem, I'll put one aside for you.
by IanS
Thu Dec 12, 2019 1:00 pm
Forum: for sale / freebies
Topic: FS: 8-bit IDE podules (A3010/A3020/A4000/A3000) - Out of Stock
Replies: 31
Views: 2669

Re: FS: 8-bit IDE podules (A3010/A3020/A4000/A3000)

Thread bump. I still have some 8-bit IDE podules for sale. See the top post in this thread for details.
by IanS
Wed Dec 11, 2019 10:08 pm
Forum: hardware
Topic: Morley 16-bit Cached SCSI Podule
Replies: 7
Views: 399

Re: Morley 16-bit Cached SCSI Podule

Sorry, I thought I had one, but it turns out it was a cumana card.
by IanS
Mon Dec 09, 2019 1:19 pm
Forum: for sale / freebies
Topic: FS: 16-bit IDE podules
Replies: 28
Views: 2130

Re: FS: 16-bit IDE podules

stevebubs wrote:
Mon Dec 09, 2019 1:07 am
I may need one or 2 but won't know until over Xmas period when I take stock of where I am in the rebuilds.
I can't see me running out before then.
by IanS
Sun Dec 08, 2019 10:59 pm
Forum: hardware
Topic: BBC Startup Beeps
Replies: 3
Views: 251

Re: BBC Startup Beeps

I read in web page: http://wouter.bbcmicro.net/bbc/hardware/bbc_micro/repair/index.html The first beeeeeeeee noise is random data on the slow data bus (hanging off the system 6522) being interpreted and amplified by the 76489 sound chip. It stops once the OS has configured the system VIA. If the OS...