Search found 2790 matches

by jonb
Sat Feb 27, 2021 9:41 pm
Forum: general
Topic: Today I received.....
Replies: 6133
Views: 700927

Re: Today I received.....

Nice motor Jon 8) Remember: essential journeys only, and you must stay local until March the 29th at the earliest :D Lee. Yes, Lee. I had some essential shopping to do this morning, and was not very surprised by the large number of other road users in classic cars, soft tops and on motorcycles doin...
by jonb
Sat Feb 27, 2021 9:15 am
Forum: general
Topic: Today I received.....
Replies: 6133
Views: 700927

Re: Today I received.....

A proper toy..

Yellow Elise.jpg

:P

(PS, I like the drive units, Ken. Nice!)
by jonb
Thu Feb 25, 2021 9:09 am
Forum: other vintage hardware, software and languages
Topic: Micro UK101
Replies: 20
Views: 2197

Re: Micro UK101

I expect Grant would be OK about it as the seller is openly crediting his work. And that's a good price for a board like that (even though you can get them made for about 25% if you know how to lay it out).
by jonb
Thu Feb 18, 2021 12:49 pm
Forum: general
Topic: Have you ever had one of those Hot-Collar moments?
Replies: 13
Views: 364

Re: Have you ever had one of those Hot-Collar moments?

"Have you ever had one of those Hot-Collar moments?" Many times as my scribblings on this very forum will evidence. But the scariest instance occurred when I was working nights, in charge of a £10M+ Airbus A320 flight simulator. Engineers were allocated time slots to do integration testing...
by jonb
Thu Feb 18, 2021 12:39 pm
Forum: other vintage hardware, software and languages
Topic: Anyone know what this is?
Replies: 6
Views: 411

Re: Anyone know what this is?

Yikes. Rare, valuable. Don't scrap it...
by jonb
Wed Feb 10, 2021 10:42 am
Forum: other vintage hardware, software and languages
Topic: Help me identifying power transistors
Replies: 5
Views: 264

Re: Help me identifying power transistors

Thanks for looking them up, Mark. Typically for this sort of PSU (I surmise), the transistors themselves are mounted on a flat aluminium panel in a pattern matching the PCB layout; then the PCB is fitted to the legs and it's all soldered. Hence, the transistors are not mounted on the component side ...
by jonb
Tue Feb 09, 2021 11:01 am
Forum: other vintage hardware, software and languages
Topic: Help me identifying power transistors
Replies: 5
Views: 264

Help me identifying power transistors

Hi I am looking at the MDS-II PSUs. They are meaty old things from the late '70s with multiple outputs, implemented on separate modules. One of them has a faulty 5v rail and as the current output is high, it has multiple output transistors in parallel. These are big TO-3 cased components. On one of ...
by jonb
Mon Feb 01, 2021 6:10 pm
Forum: 8-bit acorn hardware
Topic: Disk drive head cleaner
Replies: 9
Views: 371

Re: Disk drive head cleaner

You need a fibrous surface like this

0E1FA77E-16B2-406A-8D19-C858F8916C89.jpeg

It’s like a coffee filter, slightly stiff and absorbent.
by jonb
Fri Jan 29, 2021 3:05 pm
Forum: wanted
Topic: Wanted: TM100-2A floppy drive
Replies: 0
Views: 99

Wanted: TM100-2A floppy drive

Hi I'm searching for a TM100 floppy disk for my Superbrain II. I have a pair here but neither are working. Heads are misaligned. I know that some BBC micro floppy drives are TM100s (such as were fitted to the original IBM PC, TRS-80s and many other machines of the time). It must be a TM100 because t...
by jonb
Fri Jan 22, 2021 5:28 pm
Forum: other vintage hardware, software and languages
Topic: Superbrain #3 : The Superbrain II board
Replies: 186
Views: 12249

Re: Superbrain #3 : The Superbrain II board

I’m still left with a non working B: drive. A: is fine, and this is why I hadn’t considered the SB II’s drive circuitry. But eventually it dawned on me that, if the B: drive from the SB I worked fine in the SB I, but not in the SB II, it must be the SB II’s board. Oh dear. I had a look at the schema...
by jonb
Thu Jan 21, 2021 5:27 pm
Forum: for sale / freebies
Topic: Free to collector Archimedes swag
Replies: 27
Views: 3780

Re: Free to collector Archimedes swag

Hello again dear Acorn chums!

I just noticed that (most of) this stuff is still up for grabs. Anyone?

Gosh, retrocomputing stuff, you can't give it away these days! :lol:
by jonb
Thu Jan 21, 2021 5:10 pm
Forum: for sale / freebies
Topic: FS: P.R.E.S. Advanced Plus 3 disk interface for Electrons
Replies: 2
Views: 190

FS: P.R.E.S. Advanced Plus 3 disk interface for Electrons

Hi all I have a (working) PRES Advanced Plus 3 disk interface for sale. It's a plug-in module for the Electron that contains a DFS ROM and floppy drive interface. Has a 34 way drive port - see pictures below. Note, it plugs into the Acorn Plus 1 expansion box, so your Electron will need one, and of ...
by jonb
Thu Jan 21, 2021 12:31 pm
Forum: other vintage hardware, software and languages
Topic: Superbrain #3 : The Superbrain II board
Replies: 186
Views: 12249

Re: Superbrain #3 : The Superbrain II board

Fitted the adapter board last night, after spending a long, long time trying to get the uIDE port on it working. IMG_7353.jpg The adapter is the purple board to the left of the fan. It's providing the connection between the PSU board (main / aux serial ports, video signals and power) and the SB II m...
by jonb
Wed Jan 20, 2021 12:17 pm
Forum: 8-bit acorn hardware
Topic: Acorn Electron pr0n
Replies: 4
Views: 391

Acorn Electron pr0n

Some pictures of my Electron and Plus 3 rig (requested by another member).

Front view. It has Plus 3 and Plus 1 interfaces attached.
Front view. It has Plus 3 and Plus 1 interfaces attached.
Right hand side, showing the noraml Electron ports (UHF TV, Composite View, RGB Video and Cassette), plus the power socket on the Plus 3.
Right hand side, showing the noraml Electron ports (UHF TV, Composite View, RGB Video and Cassette), plus the power socket on the Plus 3.
Rear, showing Plus 1 ports - Joystick (analogue BBC type) and printer.
Rear, showing Plus 1 ports - Joystick (analogue BBC type) and printer.
Plus 3 has a connector for a second external drive at its rear.
Plus 3 has a connector for a second external drive at its rear.
Close up of the Plus 3 drive.
Close up of the Plus 3 drive.
Manuals.
Manuals.
Manuals.
Manuals.
Underside, showing how they are all bolted together.
Underside, showing how they are all bolted together.
Acornsoft games.
Acornsoft games.
by jonb
Wed Jan 20, 2021 11:55 am
Forum: acorn atom and acorn system series
Topic: Some Atom pr0n...
Replies: 0
Views: 172

Some Atom pr0n...

Hi

Some pictures of my Acorn Atom for a new StarDot member.

Case underside.
Case underside.
Close up of the printer port.
Close up of the printer port.
Rear view. AtoMMC on left, Composite then TGB video trailing leads on right.
Rear view. AtoMMC on left, Composite then TGB video trailing leads on right.
Front view, Issue 4
Front view, Issue 4
Documents - Getting Acquainted with your Acorn Atom and Willow Utility ROM manual.
Documents - Getting Acquainted with your Acorn Atom and Willow Utility ROM manual.
Documents - Atomic Theory and Practice / Atom Technical Manual.
Documents - Atomic Theory and Practice / Atom Technical Manual.
Spare chips (replaced by ROM/RAM board).
Spare chips (replaced by ROM/RAM board).
Interior. From left to right: AtoMMC attached to top lid, RAM/ROM board, Colour board.
Interior. From left to right: AtoMMC attached to top lid, RAM/ROM board, Colour board.
Acorn promotional leaflets.
Acorn promotional leaflets.
by jonb
Mon Jan 18, 2021 5:23 pm
Forum: other vintage hardware, software and languages
Topic: Superbrain #3 : The Superbrain II board
Replies: 186
Views: 12249

Re: Superbrain #3 : The Superbrain II board

Quick update. 2xTIP110s arrived, soldered in and drives running again. New SCR arrived, soldered into the PSU and that is working too. Adapter boards arrived but the uIDE port is wired wrong. Fixed that with some patching on the PCB, but I am getting dropped bytes on the read operation. It's probabl...
by jonb
Sun Jan 17, 2021 6:41 pm
Forum: off-topic
Topic: The 8bit Guy
Replies: 9
Views: 561

Re: The 8bit Guy

8 bit guy?

I’m not a fan. People send him stuff for free which he goes on to sell. Hardly preservation. And he just got his mitts on a Kim-1. Gah...
by jonb
Thu Jan 14, 2021 3:30 pm
Forum: other vintage hardware, software and languages
Topic: Superbrain #3 : The Superbrain II board
Replies: 186
Views: 12249

Re: Superbrain #3 : The Superbrain II board

As I'm going to be messing around with the drives in the SB I I thought it'd be a good idea to print another shield... SB Drive Bay shield.jpg Although the slot isn't quite positioned correctly, it is only 2 layers so very easy to trim with a pair of scissors. And now we come to the interesting part...
by jonb
Tue Jan 12, 2021 9:55 am
Forum: other vintage hardware, software and languages
Topic: Superbrain #3 : The Superbrain II board
Replies: 186
Views: 12249

Re: Superbrain #3 : The Superbrain II board

Hi Mark

I did consider that but the TIP110 bolted to the heatsink does get quite hot, so I insulated the rear of the chassis instead (with a 3D printed cover).

I have a little more troubleshooting to do on the one servo board, then I can move on at last.
by jonb
Mon Jan 11, 2021 4:37 pm
Forum: other vintage hardware, software and languages
Topic: Superbrain #3 : The Superbrain II board
Replies: 186
Views: 12249

Re: Superbrain #3 : The Superbrain II board

Well, anyway.. after a couple of hours swapping components in and out of the TM100 servo boards, I have discovered that the culprit is the TIP-110 Darlington transistors, which are connected to the heatsinks that shorted out. I thought I'd done a successful substitution test on these already, but it...
by jonb
Sun Jan 10, 2021 4:16 pm
Forum: general
Topic: Magnifiers for help with working on PCBs
Replies: 10
Views: 548

Re: Magnifiers for help with working on PCBs

I've got a lap with a big glass in it but it does get in the way a bit when soldering. Plus, if the lamp is not square to the board it makes my eyes go funny, so I am always having to adjust it.

I might try that £20 set from Amazon.
by jonb
Sun Jan 10, 2021 10:24 am
Forum: other vintage hardware, software and languages
Topic: Superbrain #3 : The Superbrain II board
Replies: 186
Views: 12249

Re: Superbrain #3 : The Superbrain II board

Yeah, your deflection is a bit squished on the right hand side. Check those caps and adjust V-HEIGHT... you can achieve a much straighter image if you want to. :)
by jonb
Sat Jan 09, 2021 1:09 pm
Forum: other vintage hardware, software and languages
Topic: Superbrain #3 : The Superbrain II board
Replies: 186
Views: 12249

Re: Superbrain #3 : The Superbrain II board

Oh no, I recapped it entirely (all electrolytics). And found a supplier of bipolar caps that don't explode, so my boards (both) have the correct electrolytic at C441 (and they are titchy compared to the old ones - 63v as well). God, no, not old Macs. Worthless junk. Even old PCs are more valuable. I...
by jonb
Sat Jan 09, 2021 10:44 am
Forum: other vintage hardware, software and languages
Topic: Superbrain #3 : The Superbrain II board
Replies: 186
Views: 12249

Re: Superbrain #3 : The Superbrain II board

I'm not convinced your problem is the BU406. Your screen looks quite different to mine when I had the bad 406 fitted. I had compressed characters on the right third of the screen that got more and more squished the further to the right you looked, ending in a vertical white line. That looks like wha...
by jonb
Wed Jan 06, 2021 12:22 pm
Forum: other vintage hardware, software and languages
Topic: Superbrain #3 : The Superbrain II board
Replies: 186
Views: 12249

Re: Superbrain #3 : The Superbrain II board

While I wait for the parts needed to repair my Tandon drives, I have been revisiting the Gotek display problem. I figured that it was the OLED display itself that was getting upset, as the drive still worked with the corrupt display. What if I switched the OLED power with the relay? It worked, hoora...
by jonb
Tue Jan 05, 2021 3:29 pm
Forum: other vintage hardware, software and languages
Topic: Superbrain #3 : The Superbrain II board
Replies: 186
Views: 12249

Re: Superbrain #3 : The Superbrain II board

I seem to be burning through working drives today.

While testing one of these Tandon drives on a PC I had another incidence of the "shorted heatsink" and now it, too is dead.

"Frak!" :evil:
by jonb
Tue Jan 05, 2021 10:15 am
Forum: wanted
Topic: WANTED - Acorn Atom + Accessories
Replies: 5
Views: 393

Re: WANTED - Acorn Atom + Accessories

I have an Issue 4 Atom with modern ROM/RAM, colour board and SD card reader with all manuals and the original schematic. 5V conversion. Original memory chips if you wanted to go back to standard. It is in very good condition but no box / ploys. Feel free to PM an offer. I also have an Electron with ...
by jonb
Mon Jan 04, 2021 5:12 pm
Forum: other vintage hardware, software and languages
Topic: Superbrain #3 : The Superbrain II board
Replies: 186
Views: 12249

Re: Superbrain #3 : The Superbrain II board

Back to the drive itself. It has known good controller and servo boards fitted, but still, I can't seem to get it to work. I wonder if the heads are degraded..? I have another chassis I can try (this one hasn't been fiddled with as regards radial alignment) and then it's off to eBay. :roll:
by jonb
Mon Jan 04, 2021 3:09 pm
Forum: other vintage hardware, software and languages
Topic: Superbrain #3 : The Superbrain II board
Replies: 186
Views: 12249

Re: Superbrain #3 : The Superbrain II board

Later that very same day...


There's a folded flange that tucks under the metal parts to secure it in place.
There's a folded flange that tucks under the metal parts to secure it in place.


Fits right in and protects the sevo boards on the drives from shorts when they are being worked on.
Fits right in and protects the sevo boards on the drives from shorts when they are being worked on.


The drive bay cover is complete.
The drive bay cover is complete.

Go to advanced search