Search found 1569 matches

by steve3000
Wed Jun 21, 2017 5:59 pm
Forum: hardware
Topic: Risc OS 3.11 IDE disc rename problem
Replies: 8
Views: 199

Re: Risc OS 3.11 IDE disc rename problem

JonC wrote:I may have misunderstood, but have you run a *opt 4,3 (Think this is the right one!)

Great suggestion, it's *opt 4,2 for a RISC OS boot file. :)
by steve3000
Tue Jun 20, 2017 10:00 pm
Forum: hardware
Topic: Dead A3010 help... PSU maybe?
Replies: 26
Views: 469

Re: Dead A3010 help... PSU maybe?

Zarchos wrote:Please show us 3)

OK: viewtopic.php?f=16&t=13291#p173332

:D
by steve3000
Tue Jun 20, 2017 9:59 pm
Forum: hardware
Topic: Fitting an external keyboard to A3010/A3020
Replies: 2
Views: 67

Fitting an external keyboard to A3010/A3020

While repairing my A3010 here , I needed to connect an external keyboard since the internal keyboard circuitry was damaged. It's quite easy to build a suitable adaptor using a PS/2 socket since Archimedes keyboards use PS/2 connectors *but note: the Archimedes keyboards are not PS/2 compatible*, so ...
by steve3000
Mon Jun 19, 2017 10:08 pm
Forum: hardware
Topic: Dead A3010 help... PSU maybe?
Replies: 26
Views: 469

Re: Dead A3010 help... PSU maybe?

Some useful learnings: 1) RISC OS 3 won't boot with the CMOS RAM IC (PCF8583T) missing - it will just flash out a POST message from the floppy drive, with "CMOS RAM Unreadable" as the error. 2) Failed internal keyboard circuitry is a pain to deal with on the A3010, mainly because you canno...
by steve3000
Mon Jun 19, 2017 9:52 pm
Forum: hardware
Topic: Dead A3010 help... PSU maybe?
Replies: 26
Views: 469

Re: Dead A3010 help... PSU maybe?

So what was the cause of the short circuit and how did I fix it? I think I've at least narrowed it down to one of two things: 1) failed IC5 (CMOS RAM/clock IC PCF8583T) causing a short or 2) failed C74 electrolytic cap causing a short The burning/smokey smell I think I've narrowed down in part to th...
by steve3000
Mon Jun 19, 2017 9:20 pm
Forum: hardware
Topic: Dead A3010 help... PSU maybe?
Replies: 26
Views: 469

Re: Dead A3010 help... PSU maybe?

She lives!

DSC_4041.JPG

DSC_4045.JPG

DSC_4046.JPG
by steve3000
Mon Jun 19, 2017 1:14 am
Forum: hardware
Topic: A3000 - No video
Replies: 27
Views: 492

Re: A3000 - No video

Nice ARM3! :D For the screen going blank in vga modes it must be because the memory bus is still at 8 Mhz, and not 12 Mhz ... That's the reason. Arm3 doesn't fix this unfortunately, but the blanking should only happen for floppy discs, not hard discs, and only in high resolution (640x350 and above) ...
by steve3000
Mon Jun 19, 2017 12:55 am
Forum: hardware
Topic: Replacing an A3010 set of keyboard connectors
Replies: 7
Views: 133

Re: Replacing an A3010 set of keyboard connectors

Same result unfortunately. No floppy drive on thiq machine. I will install one in a few hours. Ok, make sure to switch lk14 back to 1-2, or that'll confuse things further if you forget. I mesure South West of the motherboard, where it is written -12VU 0V +5V +12VU Ok, that's the unregulated 12v, wh...
by steve3000
Sun Jun 18, 2017 10:46 pm
Forum: hardware
Topic: Replacing an A3010 set of keyboard connectors
Replies: 7
Views: 133

Re: Replacing an A3010 set of keyboard connectors

I failed... I have mesured the voltages at the 5 an 12 volts and I get 5.10 and 10.85 ... any idea what could be wrong ? And here is what I get on screen : 14978174424881574279050.jpg Voltages are ok, at least it should boot with those voltages. (Where are you measuring the 12v, and is that the reg...
by steve3000
Fri Jun 16, 2017 7:13 pm
Forum: hardware
Topic: Resurrecting a dead A3010
Replies: 8
Views: 183

Re: Resurrecting a dead A3010

I think the drive flash pattern's dictated by the ROM isn't it? d. Yes the flashing drive light is the self test code which is executed from the ROMs. If you see the flashing light this means the ARM and ROMs are functioning correctly. You don't need RAM to run the self test, but you do need the RO...
by steve3000
Fri Jun 09, 2017 8:21 pm
Forum: hardware
Topic: Archi noob has many questions...
Replies: 13
Views: 309

Re: Archi noob has many questions...

How can I format an IDE drive to 785 Mbytes with !HForm on my A3020 then, if there is a limit at 512 Mbytes ? Have you tried putting >512 mb of files on it yet? If you use a new version of !HForm it might allow you to format a drive to >512mb, but it can't use this space under RISCOS 3.1, because f...
by steve3000
Fri Jun 09, 2017 12:17 pm
Forum: hardware
Topic: Dead A3010 help... PSU maybe?
Replies: 26
Views: 469

Re: Dead A3010 help... PSU maybe?

Whatever was causing the short has now damaged itself further due to the power from the PSU causing localised heating in the component. The bouncing voltage on the 5V line indicates that the "insulation" in the defective component kept "breaking down". It's now likely that the l...
by steve3000
Thu Jun 08, 2017 11:14 pm
Forum: hardware
Topic: Dead A3010 help... PSU maybe?
Replies: 26
Views: 469

Re: Dead A3010 help... PSU maybe?

However, I suspect the CMOS RAM chip has fried itself. :( Definitely looking like this now. Computer is flashing out the code for "CMOS RAM checksum failed" on start up, even with delete-power on. I'll need to find a replacement for this IC to get further I suspect, however I'm still wond...
by steve3000
Thu Jun 08, 2017 10:47 pm
Forum: introduce yourself
Topic: Archimedes noob here
Replies: 9
Views: 201

Re: Archimedes noob here

Welcome!

The RISC OS manual from 1989 will be for RISC OS 2, so not ideal to learn RISC OS 3.11 as you have on your A410.

You might do well to get (or burn) a set of RISC OS 3.19 ROMs for your computers, like mine:

DSC_3743.JPG
by steve3000
Thu Jun 08, 2017 10:38 pm
Forum: hardware
Topic: Dead A3010 help... PSU maybe?
Replies: 26
Views: 469

Re: Dead A3010 help... PSU maybe?

At that point, I'd had enough for the time. But after a couple of days, I came back to the electrolytics - starting with the 4 electrolytics marked as "bulk decoupling" on the circuit diagram. I removed and tested all 4, but all were OK, and no change on the PCB +5v to 0v 2.2 ohm resistanc...
by steve3000
Thu Jun 08, 2017 10:16 pm
Forum: hardware
Topic: Dead A3010 help... PSU maybe?
Replies: 26
Views: 469

Re: Dead A3010 help... PSU maybe?

Time for an update. I made some progress today, but first here's update part 1, which I should have posted two days ago. Before tackling the electrolytics, I noticed that the mezzanine board itself had two surface mounted tants on top. I don't have any surface mount removal kit, and was just using m...
by steve3000
Tue Jun 06, 2017 10:00 pm
Forum: software: other
Topic: Turning off Keyboard Echo
Replies: 12
Views: 238

Re: Turning off Keyboard Echo

I always used VDU21 and VDU6.

eg.

PRINT"Enter Password:";:VDU21:INPUT A$:VDU6
by steve3000
Sun Jun 04, 2017 11:19 am
Forum: hardware
Topic: Dead A3010 help... PSU maybe?
Replies: 26
Views: 469

Re: Dead A3010 help... PSU maybe?

I presume you have checked the resistance between +5V and 0V after removing each tantalum? Hi Mark, yes tested this after removing each one and with all removed. And tested resistance of each cap individually. Have you refitted them? Have you tried powering up the computer section of the board? Tan...
by steve3000
Sun Jun 04, 2017 12:01 am
Forum: hardware
Topic: Dead A3010 help... PSU maybe?
Replies: 26
Views: 469

Re: Dead A3010 help... PSU maybe?

steve3000 wrote:Next step I guess is pulling the 7 tant caps on the computer side and testing each...?

All tant caps removed and tested OK.

Next... electrolytics! There are a lot of these, any good place to start?
by steve3000
Sat Jun 03, 2017 10:03 pm
Forum: hardware
Topic: Dead A3010 help... PSU maybe?
Replies: 26
Views: 469

Re: Dead A3010 help... PSU maybe?

Right, had a poke around and looking at the A3010 circuit diagram, LK1 (wire link) bridges the PSU +5v line to the computer side +5v line. LK2 (push-on link) does the same for +12v line. So I removed LK1 and LK2 and checked resistance between +5v and 0v on PSU and computer side. Computer side was 2....
by steve3000
Sat Jun 03, 2017 1:25 pm
Forum: hardware
Topic: Dead A3010 help... PSU maybe?
Replies: 26
Views: 469

Re: Dead A3010 help... PSU maybe?

Not having looked at the schematics for this PSU, this is generic advice: If the power supply detects a short circuit of the main output (read as normally the highest current rail), it will reduce the power output, hence all outputs will have reduced voltages. Check for tantalum capacitors, these a...
by steve3000
Sat Jun 03, 2017 1:21 pm
Forum: hardware
Topic: Dead A3010 help... PSU maybe?
Replies: 26
Views: 469

Re: Dead A3010 help... PSU maybe?

vectorlight wrote:I've had 2 issues with the A3010 PSU dishing out the wrong voltage and in both instances was fixed by replacing the 2 big electrolytic caps (C10 & C17 I think) :D

Ok, great. I'll take a look at these next.
by steve3000
Sat Jun 03, 2017 1:20 pm
Forum: hardware
Topic: Dead A3010 help... PSU maybe?
Replies: 26
Views: 469

Re: Dead A3010 help... PSU maybe?

Zarchos wrote:Close all windows in order not to be tempted to throw it in the yard ... :cry:

Windows closed! :)
by steve3000
Sat Jun 03, 2017 1:19 pm
Forum: hardware
Topic: Dead A3010 help... PSU maybe?
Replies: 26
Views: 469

Re: Dead A3010 help... PSU maybe?

If there is a tantalum capacitor across the 5v line or even a normal electrolytic then yes. Use a multimeter to check for a short on the motherboard. Thanks. Humm, 2.1 ohms from 5v to 0v..! Sounds like a short? Need to isolate the problem now, which is slightly tricky with the psu being part of the...
by steve3000
Sat Jun 03, 2017 12:43 pm
Forum: hardware
Topic: Dead A3010 help... PSU maybe?
Replies: 26
Views: 469

Dead A3010 help... PSU maybe?

After some thoughts/pointers on this. I have recently been repairing a seriously battery damaged mezzanine A3010 (probably the most badly damaged computer I've tackled in terms of battery damage), and finally last night it was nearly 100% working (everything apart from some tracks on the keyboard co...
by steve3000
Sat Jun 03, 2017 12:27 pm
Forum: hardware
Topic: Which Archimedes model?
Replies: 16
Views: 317

Re: Which Archimedes model?

Get the cheapest one you can find, I wouldn't pay more than £30 if you just want to satisfy your retro calling. There's very little to tell them apart at the desktop, underneath they differ wildly in chipset and CPU, but I wouldn't worry about that until you know what you want to do with it. Agree ...
by steve3000
Tue May 30, 2017 1:23 pm
Forum: wanted
Topic: Wanted - A3000 IDE podule
Replies: 65
Views: 1072

Re: Wanted - A3000 IDE podule

If space is tight on the Eprom is it possible to !Squash the modules and have 'just' a piece of code calling Squash to unzip the zipped contents to RAM ? I don't know much about podules, as you can read. Definitely possible :) - if you write a suitable loader...but actually that's a very good point...
by steve3000
Tue May 30, 2017 12:55 pm
Forum: software
Topic: RiscOS 2, A420/1 and Zarch
Replies: 8
Views: 451

Re: RiscOS 2, A420/1 and Zarch

Yes I'm planning to keep it as a riscoos 2 machine so a test module would be excellent! ...A few weekends later and here is a test module for RISC OS 2. :) This module won't fix Zarch, but I'm interested to know if these modes work under RISC OS 2, on your monitor - then I can work on adapting the ...

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