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Re: A5000 - diving in at the deep end!

Posted: Sun Jun 19, 2022 7:25 pm
by rubber_jonnie
stephen_usher wrote: Sun Jun 19, 2022 6:35 pm :) :dualthumbup:
I've since also upgraded to the latest version of the SCSI ROM too thanks to the good folks over at Stardot. I see you posted there regarding your BBC B floppy issue, any luck?

Re: A5000 - diving in at the deep end!

Posted: Sun Jun 19, 2022 8:58 pm
by stephen_usher
Nope! I can't find any difference in signals between the working and non-working Beeb!

Re: A5000 - diving in at the deep end!

Posted: Sun Jun 19, 2022 9:17 pm
by rubber_jonnie
stephen_usher wrote: Sun Jun 19, 2022 8:58 pm Nope! I can't find any difference in signals between the working and non-working Beeb!
Oh, that's a bit arse...

Re: A5000 - diving in at the deep end!

Posted: Sun Jun 19, 2022 10:04 pm
by stephen_usher
Yeah. Without a 40 pin chip-clip I can't really fit a logic analyser in the FDC. I think that's the only way I'll solve this, by looking at all the signals together in the time domain.

Re: A5000 - diving in at the deep end!

Posted: Sun Jun 19, 2022 11:28 pm
by rubber_jonnie
stephen_usher wrote: Sun Jun 19, 2022 10:04 pm Yeah. Without a 40 pin chip-clip I can't really fit a logic analyser in the FDC. I think that's the only way I'll solve this, by looking at all the signals together in the time domain.
Do you have an 8271 controller? If so does it work in another machine?

EDIT: Just reading your posts over at stardot, please ignore any questions you've already answered over there.

Re: A5000 - diving in at the deep end!

Posted: Mon Jun 20, 2022 4:12 pm
by rubber_jonnie
Ok, so for now at least, I have decided to call the A5000 done, and I'm reassembling it.

:girldance: :girldance: :girldance:

All the repairs are done, and whilst I could easily continue tinkering with the IDE interface, in reality, having the SCSI drive means it isn't entirely necessary. Plus I can easily add another SCSI drive if I need to.

My limited selection of IDE drives seems to be a problem too, since it seems to be sensitive to different drive sizes and geometries.

I'll possibly revisit IDE later, but as far as I can tell, I have caught all the battery damage and everything buzzes out ok, the CMOS/RTC is working fine and the battery replacement is also working well.

The one item I won't be repairing are the traces to the FPA socket, since the FPAs are quite expensive and kind of unnecessary. I have fitted a socket to make it look nice, but only the 4 corner pins are soldered in case I change my mind later.

All the bare traces are now lacquered too.

Looking tidy inside:

PXL_20220620_145734918.jpg
PXL_20220620_145734918.jpg (315.03 KiB) Viewed 913 times

Just got to drop the lid back on. Mouse working too, I changed from the heat shrink on the rollers with silicone tube and added the 22mm steel ball, and though it requires a surface with a decent amount of friction to work, work it does :)

Total tally of repairs:

1x CMOS/RTC chip
1x 74HCT245 buffer
7x mainboard capacitors (Maybe a few more than that!!)
15x capacitors in the PSU (Super fishy PSU this one!)
A bunch of bodge wires
A ton of time :)

It's been an interesting project, but next I need to learn properly how to drive it (The O/S is a bit, well, odd) I think network access is going to be a must too, as despite the vast array of floppy disk formats the machine can do (Good job there Acorn), it's a troublesome way to get software onto the machine.

Currently it has econet installed, but that uses a din plug, not RJ45, so at present it is very much offline.

Re: A5000 - diving in at the deep end!

Posted: Mon Jun 20, 2022 4:15 pm
by exxos
:bravo: :girldance: :girldance: :girldance:

Re: A5000 - diving in at the deep end!

Posted: Mon Jun 20, 2022 4:30 pm
by alexh
Well done. You've had yours a fraction of the time I've had mine and mine is still in an antistatic bag on my desk.
rubber_jonnie wrote: Mon Jun 20, 2022 4:12 pm My limited selection of IDE drives seems to be a problem too, since it seems to be sensitive to different drive sizes and geometries.
Did you follow the advice and add the extra ICS Wizzo IDEFS ROM in the spare ROM socket?

https://stardot.org.uk/forums/viewtopic.php?t=11247

I'm not familiar with this product but I was interested to learn. People claim it adds increased compatibility over ADFS in RISCOS3.11

Re: A5000 - diving in at the deep end!

Posted: Mon Jun 20, 2022 4:38 pm
by rubber_jonnie
alexh wrote: Mon Jun 20, 2022 4:30 pm Well done. You've had yours a fraction of the time I've had mine and mine is still in an antistatic bag on my desk.

Did you follow the advice and add the extra ICS Wizzo IDEFS ROM in the spare ROM socket?

https://stardot.org.uk/forums/viewtopic.php?t=11247

I'm not familiar with this product but I was interested to learn. People claim it adds increased compatibility over ADFS in RISCOS3.11
Thanks :)

Once I get my hands on a machine I do go all in, sometimes for weeks, in order to get them running, fixing any of these machines is such a buzz.

No, I haven't tried the ICS Wizzo IDEFS ROM, well not yet, but it is on the to-do list, I just need to do some more digging to see what the process is.

Don't worry, when and if I do test it, I'll put it on here :)

Re: A5000 - diving in at the deep end!

Posted: Mon Jun 20, 2022 5:43 pm
by alexh
The Wisso5 ROM binary is in that thread together with instructions to use a 27C512 EPROM. There should be an empty 5th ROM socket. Just pop it in. Well that's my thinking. Obviously but tried it yet. But I want to.