Off-topic-ish. Microdigital Omega.

[IanJeffray]

More junk^H^H^H^Hgoodies from AndyMc1280 for me to sort out.

Case is heavily mangled, but the machine does boot. StrongARM gets fairly warm very quickly. Manages to softload Select from the IDE drive. But ... no keyboard or mouse functionality. Boo.

There's very little on this board that I recognise from any other Acorn machine, except the StrongARM and RTC.

RTC battery had already been removed, and appears to have leaked a little but no significant board damage. Looks like at least two caps have leaked - some fairly corroded vias and other stuff to clean up:

New caps, all good....

After this, I noticed one more leaky mess near the PS/2 sockets. Swapped and cleaned.

But, not surprisingly, this hasn't made the keyboard or mouse work.
There's 5V and GND at the appropriate pins of each PS/2 connector.
I've tried a mouse that's supposed to be known to work, and three different PS/2 keyboards (including a genuine Acorn RiscPC keyboard).

Where do we go from here?

[IanJeffray]

Further inspection found more very grotty vias and 'growing' stuff next to capacitors, so two more swapped. No change in operation. It seems like the Omega may be classified as having "capacitor issues" though!

[daveejhitchins]

Is there any information here that will help?

Dave H.

[IanJeffray]

Is there any information here that will help?

Wow. Full CAD schematics and gerbers. CPLD source code. Bit images for things. Lovely. Ta.

[RobC]

I really like my Omega. It's a bit temperamental but feels close to what Phoebe would have been.

I could do with recapping it. Any advice on how to safely remove he SMD caps would be greatly appreciated.

[IanJeffray]

I could do with recapping it. Any advice on how to safely remove he SMD caps would be greatly appreciated.

There's lots of debate on this. I personally favour the "can snip" method which I've described elsewhere on *. - notably for A4 fixes:

• With side cutters, cut the can above the plastic base. Cut perpendicular to the pads, so you're effectively pulling them toward each other. Push down on the top of the cap as you do this, to try and limit the upward pulling force on the pads.
• Once the can top is off, you can usually prise the bottom off, leaving the plastic base and two leads sticking up.
• Use side cutters again to cut away the remaining parts of the leads above the plastic - again put your finger over the leg remnant as you cut to avoid the small part flying somewhere unwanted.
• Lift the plastic spacer off.
• Mop up the inevitable additional cap leakage caused by the cutting force on the cap.
• Remove the leg remnants from the pads by applying fresh solder.
• Wick and clean.

Since Dave's thread already agrees that a full re-cap is recommended, and I've a few more to do on this Omega in that case, here's photos of the process - a nice easy one at the board corner:

[AndyMc1280]

More junk^H^H^H^Hgoodies from AndyMc1280 for me to sort out.

Ah C'mon, at least I bring you Interesting... er.... crap, to play with. That's the point

[IanJeffray]

Buzz-out the PS2 and it's fine through the fuse and 5V input.
But measure it live, it's 0.1V.
How can this be?
I'm not sure, but ... unplug the VGA cable and ... it's 5V again!
Swap to my AKF85 and its BNC input cable... and mouse and keyboard are working just fine!

So the Omega doesn't like a fully wired VGA cable? What on earth? Something super-funny going on there. But I've seen this kind of thing before with one of my A3020s which makes the VGA cable get very hot! So odd.

[IanJeffray]

Several more 220uF caps swapped-out. Now I've run out of 'em. More ordered.
Andy had already snipped out the RTC battery, but there was a little track damage and corrosion around the area. Patched up, and added coloured 0.1" header pins to accept an offboard cell.

[AndyMc1280]

Several more 220uF caps swapped-out. Now I've run out of 'em. More ordered.
Andy had already snipped out the RTC battery, but there was a little track damage and corrosion around the area. Patched up, and added coloured 0.1" header pins to accept an offboard cell.

IMG_E9705.JPG

Ta! Yes the battery was kind of an emergency "lets get rid of this b@stard" at 12.30 am one night, since I hadn't even looked at the Omega for ages...

[thecellartroll]

Wow. Full CAD schematics and gerbers. CPLD source code. Bit images for things. Lovely. Ta.

Now we need to find a bin full of 300Mhz StrongARMs!

[IanJeffray]

Wow. Full CAD schematics and gerbers. CPLD source code. Bit images for things. Lovely. Ta.

Now we need to find a bin full of 300Mhz StrongARMs!

Do we?
I'm presently archiving the drive via ShareFS and the Omega's PCI Network card.
It's as slow as treacle. Under 100K/sec write, 35K/sec read. It's set itself up as half-duplex which can't be helping, but urgh the experience is pretty dreadful. I'm still amazed it works at all, though.

ArmSI falls over throwing a logarithm error. Need to poke sirbod

[RobC]

There's lots of debate on this. I personally favour the "can snip" method which I've described elsewhere on *. - notably for A4 fixes:
With side cutters, cut the can above the plastic base. Cut perpendicular to the pads, so you're effectively pulling them toward each other. Push down on the top of the cap as you do this, to try and limit the upward pulling force on the pads.
Once the can top is off, you can usually prise the bottom off, leaving the plastic base and two leads sticking up.
Use side cutters again to cut away the remaining parts of the leads above the plastic - again put your finger over the leg remnant as you cut to avoid the small part flying somewhere unwanted.
Lift the plastic spacer off.
Mop up the inevitable additional cap leakage caused by the cutting force on the cap.
Remove the leg remnants from the pads by applying fresh solder.
Wick and clean.

Many thanks - that's really helpful. I'd read various debates but wanted definitive advice from someone i trust.

Do we?
I'm presently archiving the drive via ShareFS and the Omega's PCI Network card.
It's as slow as treacle. Under 100K/sec write, 35K/sec read. It's set itself up as half-duplex which can't be helping, but urgh the experience is pretty dreadful. I'm still amazed it works at all, though.

I think there are two flavours of network drivers for the Omega: slow but reliable and fast but flaky. I think I have the latter installed on mine.

I have started looking at modifying the Castle USB drivers so that the Omega can use the same sort of USB PCI card as the Iyonix. Just need to find time to finish it.

[AndyMc1280]

To update slightly:

Omega has been recased
New Battery fitted offboard.
I am waiting on an IDE DOM to replace the 40gb drive that is knackered. Has a 160gb spinner in there though.
Ian is going to post more pics.
!Si now works.... (dunno what was up)

Weird issues with RAM. Have 256+64 Mb in it. Take the 64 out no worky.... tried all combos and 256 on its own. Meh.

For any omega owners... does anybody have a copy of the g revision firmware? I've got 4.2f (or whatever it is)

[IanJeffray]

Old case that was mashed by courier:

New case is a notably smaller/lighter Antec VSK-3000B.
Rear view, with sticker also carefully transferred from the old:

Omega guts transferred. Those disgusting orange IDE cables will go soon. Even the case fan just plugs straight in to the motherboard header. Front I/O & buttons are PC standard connectors and plug straight in. Original PSU used.

Andy wants an Omega sticker on the front, otherwise it's stealth PC:

ARMSI (4.00) reports 178mips/564KFlops for the 300MHz Omega.
This compares to 163mips/469KFlops for my 287MHz RiscPC.

[thecellartroll]

I think I still have the equally hideous bright yellow versions of those cables somewhere! I'm interested in what will be less ugly though; old-school grey ribbon cables are not so nice either. Rainbow cables?

[IanJeffray]

I'm interested in what will be less ugly though; old-school grey ribbon cables are not so nice either.

Black. And only one, since the primary drive will be a DOM plugged straight in to the motherboard.

[thecellartroll]

Black. And only one, since the primary drive will be a DOM plugged straight in to the motherboard.

IDEs.jpeg

Ah yes, that will be an improvement!

[helpful]

Replying from my Omega!

I think there are two flavours of network drivers for the Omega: slow but reliable and fast but flaky.

Attached is a zip of the two versions of the Omega EtherH driver that I have:
- v4.34 is very slow, about 50KB/s, but stable
- v4.38 is fairly quick, about 5MB/s, but has issues

What I found BITD was that v4.38 was fine except if a Windows machine was on the same network(!) which would cause it to stop responding. As I had no Windows machines, I happily used v4.38 for many years with no problems. However having just tried it now, I find it dies after a minute or two even though there are still no Windows machines here, so I guess something else on my network is now sending out packets it doesn't like It doesn't crash, simply stops responding. A quick RMReInit EtherH will get it going again, but only for another few minutes. I guess if you connect it to a router/switch that has port filtering you could restrict what traffic gets to it and so keep it going that way?

I have started looking at modifying the Castle USB drivers so that the Omega can use the same sort of USB PCI card as the Iyonix. Just need to find time to finish it.

Interesting, if 20 years late!

For any omega owners... does anybody have a copy of the g revision firmware? I've got 4.2f (or whatever it is)

I have 1.15g, but only in the Omega! It's what it came with, so I don't have the files to flash it.

Bryan.

[IanJeffray]

@AndyMc1280 was over to collect the Omega today, so I set it up for use. Panic and gloom - the keyboard and mouse wouldn't work. I expected the fuse had died. But thanks to Andy having a better memory of my own activities than I do (!) he rememered a posting a made further up this thread describing the same issue, which I'd completely forgotten about -- sure enough, unplugging the VGA cable to the AKF85 made the keyboard and mouse work!! Switch over to using the BNC input - it's fine. So it's the VGA cable? Nope - because we hooked up a DELL 2007FP and it's fine with the same cable - we deduced that it's the combination of the AKF85 with VGA input on the 'new' VGA cable that's upsetting Omega. Sounds like the same issue as @flaxcottage is describing here viewtopic.php?p=355927#p355927 - very odd. Anyway - we fitted a nice black IDE cable and all was good - here's the finished machine with its guts on show:

And in "sleeper PC" guise:

[AndyMc1280]

Yay

Many thanks for fettling and faffing. Had minor need for new underwear when you said "er it's not working" but we got there in the end. Looks great

[SarahWalker]

Benchmarks please! (since I'm highly unlikely to ever own one)

If it's as RPC compatible as Microdigital claimed then it should be able to run everything in the Benchmarks thread.

[daveejhitchins]

@AndyMc1280 was over to collect the Omega today, so I set it up for use. Panic and gloom - the keyboard and mouse wouldn't work. I expected the fuse had died. But thanks to Andy having a better memory of my own activities than I do (!) he rememered a posting a made further up this thread describing the same issue, which I'd completely forgotten about -- sure enough, unplugging the VGA cable to the AKF85 made the keyboard and mouse work!! Switch over to using the BNC input - it's fine. So it's the VGA cable? Nope - because we hooked up a DELL 2007FP and it's fine with the same cable - we deduced that it's the combination of the AKF85 with VGA input on the 'new' VGA cable that's upsetting Omega. Sounds like the same issue as @flaxcottage is describing here viewtopic.php?p=355927#p355927 - very odd. Anyway - we fitted a nice black IDE cable and all was good - here's the finished machine with its guts on show:
DSC_0304.jpg

And in "sleeper PC" guise:
DSC_0314.jpg

A little late, however, this is a reply from Dave Prosser on Ian's comments above:

With respect to monitors for the Omega, this was designed to work with the 'recent' (at the time) new spec for PC monitors - for auto detection of the screen type/resolution/timings, rather than the old, very proprietary, system that Acorn used to use. The AKF85 was used by me when testing, but was technically already obsolete (in the sense that Acorn had already long since replaced it with AKF90+ models). If the monitor doesn't come up at start up, it could just be that you need to force an override of the auto-detection to make it use a sensible, appropriate output format. Once upon a time, I used to know how to do that, blind - as no monitor image - from the command line, I think??? Don't really remember. These days I am testing with 163" All-in-One screens (using so-called MicroLED technology) - so these are 'LED screens' that DON'T have an LCD in front...

Dave H.

[IanJeffray]

A little late, however, this is a reply from Dave Prosser on Ian's comments above:

.... it could just be that you need to force an override of the auto-detection to make it use a sensible....

Heck no. The monitor cable (when plugged in to an AKF85) actually pulls down the PS2 power rail. It's a long way from a software configuration issue

[daveejhitchins]

Ha! Remote diagnosis . . .

Dave H.

[paulb]

A little late, however, this is a reply from Dave Prosser on Ian's comments above:

With respect to monitors for the Omega, this was designed to work with the 'recent' (at the time) new spec for PC monitors - for auto detection of the screen type/resolution/timings, rather than the old, very proprietary, system that Acorn used to use. The AKF85 was used by me when testing, but was technically already obsolete (in the sense that Acorn had already long since replaced it with AKF90+ models). If the monitor doesn't come up at start up, it could just be that you need to force an override of the auto-detection to make it use a sensible, appropriate output format. Once upon a time, I used to know how to do that, blind - as no monitor image - from the command line, I think??? Don't really remember. These days I am testing with 163" All-in-One screens (using so-called MicroLED technology) - so these are 'LED screens' that DON'T have an LCD in front...

Dave H.

I guess he is talking about one of the Display Data Channel technologies, maybe DDC2. I don't know what Acorn used to use, but maybe it was related to the three-pin pre-DDC approach documented on the referenced page.

[IAMNOTDEFECTIVE]

I got nothing meaningful to add... however I want to congratulate you on obtaining an Omega in the first place even if it was worse for wear! I've been searching for one for 8ish years and never saw one pop up - so you've done better then me! ^^"

At this rate I think it'll be easier waiting for those mITX Pi boards R-Comp or ROSBits are working on and try to produce a Omega-lookalike case and pretend I own one.

[daveejhitchins]

At this rate I think it'll be easier waiting for those mITX Pi boards R-Comp or ROSBits are working on and try to produce a Omega-lookalike case and pretend I own one.

When I cleared the Baildon Electronics premises, I found and recovered a number of cases and PSUs, presumably from the Omega build? However, it was a slightly different style* than the photos I've seen. I'm wondering if these were from, maybe, a prototype build. I'll ask the question next time I contact Dave P. Of the PSUs I recovered I believe I have one left - not that it's anything special - but if anyone want like it (?) it would be just the postage cost . . .

* I'll pop a photo up (here) of the one I've been using for my main PC for a number of years now. I removed the door quite early on, as it broke - maybe that's the reason for the change?

If I get to know the location of the next Wakefield show and it's Bradford, I may be able to persuade Dave to attend and give a talk about the design and build of the Omega - that may draw more people to attend!?

Dave H.

[AndyMc1280]

At this rate I think it'll be easier waiting for those mITX Pi boards R-Comp or ROSBits are working on and try to produce a Omega-lookalike case and pretend I own one.

When I cleared the Baildon Electronics premises, I found and recovered a number of cases and PSUs, presumably from the Omega build? However, it was a slightly different style* than the photos I've seen. I'm wondering if these were from, maybe, a prototype build. I'll ask the question next time I contact Dave P. Of the PSUs I recovered I believe I have one left - not that it's anything special - but if anyone want like it (?) it would be just the postage cost . . .

* I'll pop a photo up (here) of the one I've been using for my main PC for a number of years now. I removed the door quite early on, as it broke - maybe that's the reason for the change?

If I get to know the location of the next Wakefield show and it's Bradford, I may be able to persuade Dave to attend and give a talk about the design and build of the Omega - that may draw more people to attend!?

Dave H.

Hold the PSU.... if no one else wants. I may have fudged mine. Today I am driving over to @IanJeffray with omega. Due to the fact I am an unspeakable teapot and made a huge f.... booboo, I have a non working omega again.

Pro tip : don't fanny about inside case in poor light, and when you do, don't power up with RAM sticks in the wrong way round "oo sparky" is not a nice view to have

Worried

A

[IAMNOTDEFECTIVE]

At this rate I think it'll be easier waiting for those mITX Pi boards R-Comp or ROSBits are working on and try to produce a Omega-lookalike case and pretend I own one.

When I cleared the Baildon Electronics premises, I found and recovered a number of cases and PSUs, presumably from the Omega build? However, it was a slightly different style* than the photos I've seen. I'm wondering if these were from, maybe, a prototype build. I'll ask the question next time I contact Dave P. Of the PSUs I recovered I believe I have one left - not that it's anything special - but if anyone want like it (?) it would be just the postage cost . . .

* I'll pop a photo up (here) of the one I've been using for my main PC for a number of years now. I removed the door quite early on, as it broke - maybe that's the reason for the change?

If I get to know the location of the next Wakefield show and it's Bradford, I may be able to persuade Dave to attend and give a talk about the design and build of the Omega - that may draw more people to attend!?

Dave H.

By the sound of it, you have a variation on the Yeong-Yang YY-5412 - which MicroDigital used for the "Midi Tower" SKU of the Omega. The lookalike case I'm designing in CAD is based on the "Standard" tower as I prefer the look of it, even if it is not as expandable. It's more of a "squashed" version as I've shaved 110mm of the height as I only intend to have a mITX board in it and not a mATX. I have completed the frame recently, so I'm hoping on design the actual shell from high-res photos from "Acorn User" this week when time allows. I might show it in the "off-topic" sub-forum as I don't want to derail this thread any more then I have done! ^^"