exxos's Atari, Amiga & retro forum

Well, just before we moved out to the rental, I bought a BBC Model B that arrived at our old place, but I didn't unpack it on account of the move.

Well, today was the day for its grand unpacking, and here it is topless post a quick power on test!


I've not hooked it up to a display yet, but it Boo-Bips just fine, which is a definite bonus, and the RIFAs didn't let out any smoke!! It is an issue 3, so pre-dates my other two which are issue 4.

I don't recall if it had been recapped, but the PSU will be coming out in short order for a smoke generator check!! Overall condition falls between my tatty one and my nice one, so overall pretty good, though the BBC owl on the perspex strip is a little worse for wear and it's missing the keyboard bolts and a screw or two.

It came with a full reproduction manual, which is very nice, an original users guide and a couple of other reference books.

The one weird thing is the switch hanging out the econet port hole, which looks to be some sort of ROM switch. More on that when I get it cleaned and hooked up.

I wonder if it’s a double sized EPROM and the switch is switching the high bit address line

stephen_usher wrote: 07 Jul 2021 00:17 I wonder if it’s a double sized EPROM and the switch is switching the high bit address line

It does look like the switch is connected to near the top left corner of that EEPROM...

Also looks to have the Ferranti(?) video ULA with the heatsink...just like my original issue 3 PCB...ah, the nostalgia.... :ugeek:

stephen_usher wrote: 07 Jul 2021 00:17 I wonder if it’s a double sized EPROM and the switch is switching the high bit address line

I was thinking the same. I'll check later but I think its A14. Once I have my tools unpacked I'll dump them.

I'm hopefully going to be ordering my new desks/workbench today, so can hopefully start to get things together and get working on machines again.

JezC wrote: 07 Jul 2021 08:07

stephen_usher wrote: 07 Jul 2021 00:17 I wonder if it’s a double sized EPROM and the switch is switching the high bit address line

It does look like the switch is connected to near the top left corner of that EEPROM...

Also looks to have the Ferranti(?) video ULA with the heatsink...just like my original issue 3 PCB...ah, the nostalgia.... :ugeek:

Yep, luckily my other two have the later ULA, so no heatsink needed. I may replace the heatsink, I'll see how well attached it is first though.

Happy to bring you some more nostalgia 😁

Beebs look wrong without that steel heat sink on the ULA. :-)

stephen_usher wrote: 07 Jul 2021 09:26 Beebs look wrong without that steel heat sink on the ULA. :-)

I know! I'm torn between good thermals and nostalgic aesthetics, so once I've cleaned it I'll see how well it fits and maybe just replace the thermal tape/paste.

If it's solid I'll leave it alone.

rubber_jonnie wrote: 07 Jul 2021 09:45

stephen_usher wrote: 07 Jul 2021 09:26 Beebs look wrong without that steel heat sink on the ULA. :-)

I know! I'm torn between good thermals and nostalgic aesthetics, so once I've cleaned it I'll see how well it fits and maybe just replace the thermal tape/paste.

If it's solid I'll leave it alone.

I only changed mine when endless hours of continuously playing Elite caused the black background to flicker to red... probably still have the original ULA plus heatsink somewhere... :roll:

JezC wrote: 07 Jul 2021 17:08 I only changed mine when endless hours of continuously playing Elite caused the black background to flicker to red... probably still have the original ULA plus heatsink somewhere... :roll:

:)

So I need to get this machine cleaned now, PSU is out waiting RIFA replacements and since the KBD was held in with Blu Tac (yes you heard that right!) I have replacement screws on order too.

So in the meantime I need to see which keys are playing up. I know that * isn't for sure, so I'll try blasting some contact cleaner in and a few hundred keystrokes to see if it revives them.

On the Beeb I recently repaired, some keys were fixed that way, others I had to soak in contact cleaner fora couple of days in order to revive them so if needs be I'll remove the faulty ones and do the same.

The LEDs need fixing too, they are a poor design that easily allows for the leads to push through the PCB with little force.

Since I located my soldering iron and de-solder gun yesterday, we should be good for a little TLC.