Search found 458 matches

by IanS
Mon Apr 10, 2017 7:46 pm
Forum: general
Topic: Today I received.....
Replies: 4200
Views: 223012

Re: Today I received.....

"Expandor Systems" according to the back. Not seen these before either. Thoughts? Hi, I also have a rare rom board which look a bit like yours but this rom board is for the Atom... Greetings, Wim... :-) That's guaranteed to have caught someone out at some point. The sockets are all facing...
by IanS
Sun Apr 09, 2017 5:14 pm
Forum: other vintage computer hardware, software and games
Topic: Superbrain power supplyhi
Replies: 53
Views: 1250

Re: Superbrain power supplyhi

I'd say that the PSU is almost certainly OK. In a simple flyback design like that one where only one rail is regulated, the secondary outputs (like +21V) won't be able to deliver their rated current until there's enough load on the main output (+5V here). I'm guessing the monitor is powered from +2...
by IanS
Sun Apr 09, 2017 4:31 pm
Forum: other vintage computer hardware, software and games
Topic: Superbrain power supplyhi
Replies: 53
Views: 1250

Re: Superbrain power supplyhi

jonb wrote:The first problem is the power supply. It had a burned out section with a hole in the PCB (after cleaning) the size of a 20p piece. I cleaned it and rebuilt the circuit using a tiny piece of veroboard.

Knowing which bit burnt out might give a clue.
by IanS
Thu Mar 30, 2017 9:26 pm
Forum: acorn atom
Topic: Pi-Tube Atom VDU: circles
Replies: 24
Views: 1084

Re: Pi-Tube Atom VDU: cirles

I can't figure out why the distance between the circles is not linear. Any clues? Do the circles get drawn in the right order, are any drawn our of sequence because a value is overflowing? At least one will be drawn in black, so not visible. If you draw them all in the same colour, does it look any...
by IanS
Mon Mar 27, 2017 11:28 pm
Forum: hardware
Topic: Resurrecting an early A3010
Replies: 18
Views: 751

Re: Resurrecting an early A3010

None of the pictures you posted work. Do they work for anyone else?

Just upload them to the site as attachments, no need to host them elsewhere.
by IanS
Sat Mar 18, 2017 4:23 pm
Forum: general
Topic: Today I received.....
Replies: 4200
Views: 223012

Re: Today I received.....

IanS wrote:Untested PCB. Just need to order a few more parts to build it up.
_20170313_173053.JPG

Tested.
IMG_20170318_155505007.jpg

IMG_20170318_155544769.jpg
by IanS
Thu Mar 16, 2017 10:19 pm
Forum: past events & exhibitions
Topic: ABug Leicestershire Nov 2017 - Venue & Date confirmation
Replies: 53
Views: 2410

Re: ABUG EAST MIDLANDS (Winter Warmer) 17-19 November 2017 (Leicestershire)

lazarusr wrote:I think we need to have a rule that people must divide their time between both rooms regardless of where their kit is based.

:o :o :o Really?

How do you plan to enfore this rule?
by IanS
Mon Mar 13, 2017 10:22 pm
Forum: general
Topic: Today I received.....
Replies: 4200
Views: 223012

Re: Today I received.....

Untested PCB. Just need to order a few more parts to build it up.
_20170313_173053.JPG
by IanS
Sat Mar 11, 2017 11:03 pm
Forum: hardware
Topic: Replacement 6522
Replies: 6
Views: 416

Re: Replacement 6522

daveejhitchins wrote:Parts: UM6502CE, GAL22V10D, GAL16V8D, AT28C256, AT28C256, AS6C62256A, TC514400AZ, WD1772, TMS27C512, R6522, TMS27C512, AT28C256, AT28C256

I'm guessing you have some AT28C256's, but I can't be sure.
by IanS
Wed Mar 01, 2017 7:01 pm
Forum: general
Topic: Science Museum yeast control system
Replies: 13
Views: 547

Re: Science Museum yeast control system

BigEd wrote:Computers in Control - I don't even remember that one!

There are low quality versions of the episodes around.
by IanS
Wed Feb 22, 2017 7:26 pm
Forum: off-topic
Topic: PayPal fees, WTF?
Replies: 14
Views: 1082

Re: PayPal fees, WTF?

Anyone tried Paym, I've had it set up for a couple of years, just never found anyone else with it.

http://www.paym.co.uk/
by IanS
Wed Feb 15, 2017 8:07 pm
Forum: hardware
Topic: A5000 Sound/Speaker
Replies: 2
Views: 166

Re: A5000 Sound/Speaker

The internal speaker is not disabled by connecting to the headphone socket (as you found). The internal speaker has a separate software controlled mute signal.

There is a setting in the !Configure app (under Sounds) for the internal speaker.
by IanS
Tue Feb 14, 2017 9:11 pm
Forum: hardware
Topic: Econet hub
Replies: 10
Views: 463

Re: Econet hub

The biasing bits are basically what the terminators do. When no station is driving the network the ADLC needs to be able to reliably detect that the network is undriven and therefore free for use, to this end undriven data lines must appear as a continuous stream of logic ls and not random noise whi...
by IanS
Mon Feb 13, 2017 9:58 pm
Forum: hardware
Topic: Econet hub
Replies: 10
Views: 463

Re: Econet hub

Three econet cards (and an ANFS rom) to build an Econet between my Beebs and Archimedes… You can also some ATtiny45 chips to build a clock following Simon's design and my 'Econet Hub' (8 5-pin DIN sockets mounted on a piece of veroboard -- seems easier than trailing cables and socket boxes, if it w...
by IanS
Mon Feb 13, 2017 9:46 pm
Forum: hardware
Topic: Super-simple Econet Clock design
Replies: 13
Views: 1178

Re: Super-simple Econet Clock design

When we were running my clock PCB (using your ATTiny code) at the Abug meeting, the slowest speed was a bit fast for transferring large files. It's also a bit quick for the Atom. We ended up using my old clock which runs at about 160kHz. I've since modified the code to have a 255(96), 196(64) and 18...
by IanS
Sat Feb 11, 2017 4:06 pm
Forum: hardware
Topic: Keyboard Repair
Replies: 10
Views: 561

Re: Keyboard Repair

The cable length gives a clue as to the machine it was for. That's just cruel Ian..... :lol: Someone has cut off the cable :shock: Ooops, didn't notice that bit. In an attempt to be useful, I've taken the top case from a keybord that looks like the one in the picture. Here are the connections I fou...
by IanS
Sat Feb 11, 2017 2:40 pm
Forum: hardware
Topic: Keyboard Repair
Replies: 10
Views: 561

Re: Keyboard Repair

If the keyboard has a mouse connector then it's for A3/4/5xx(x) machines.

The cable length gives a clue as to the machine it was for. The A3/4/5xx keyboards had quite short cables as they plugged in at the front of the machine. The A4/5xxx keyboards had longer cables as they plugged in at the rear.
by IanS
Wed Jan 25, 2017 8:21 pm
Forum: past events & exhibitions
Topic: ABug EAST MIDLANDS 27-29 January 2017 (Leicestershire)
Replies: 130
Views: 6831

Re: ABug EAST MIDLANDS 27-29 January 2017 (Leicestershire)

What time are people planning to get there on Friday?

Is anyone bringing an Eprom programmer that can handle a 2532 (for an Atom). Or a 21V 2764?
by IanS
Sun Jan 22, 2017 10:32 pm
Forum: past events & exhibitions
Topic: May 12th-14th 2017 Cambridge ABUG (FULL) & Acorn World event at CCfCH
Replies: 189
Views: 9312

Re: May 12th-14th 2017 Cambridge ABUG & Acorn World event at CCfCH

jbnbeeb wrote:
IanS wrote:Are zombiedog & z0m8ied0g different people? (Or is it a cunning plan to get a full table?).


:lol: and :oops: I've edited the list so we only have one z0m8ied0g !

Still got Sydney x 2 in the list.
by IanS
Sun Jan 22, 2017 9:00 pm
Forum: past events & exhibitions
Topic: May 12th-14th 2017 Cambridge ABUG (FULL) & Acorn World event at CCfCH
Replies: 189
Views: 9312

Re: May 12th-14th 2017 Cambridge ABUG & Acorn World event at CCfCH

Are zombiedog & z0m8ied0g different people? (Or is it a cunning plan to get a full table?)

I plan to do the full weekend, Friday to Sunday.
by IanS
Sun Jan 22, 2017 4:14 pm
Forum: hardware
Topic: Super-simple Econet Clock design
Replies: 13
Views: 1178

Re: Super-simple Econet Clock design

The output pins from the CPU go to opposite corners of the 4-pin header (P5), so I can easily swap the polarity, or disconnect entirely. And either output pin can feed the line driver.
by IanS
Sun Jan 22, 2017 3:07 pm
Forum: hardware
Topic: Super-simple Econet Clock design
Replies: 13
Views: 1178

Re: Super-simple Econet Clock design

So I built a new clock based on this design:- IMG_20170122_144602198.jpg It has USB power input, and the facility to add a "proper" line driver (just so I could do some comparison), power indicator, and data line biasing to avoid needing a teminator on small (and large it seems) networks. ...
by IanS
Sun Jan 22, 2017 12:00 pm
Forum: other vintage computer hardware, software and games
Topic: PCB design and fabrication
Replies: 6
Views: 454

Re: PCB design and fabrication

Did you see the other thread about pcb design - http://stardot.org.uk/forums/viewtopic.php?f=3&t=12207 I think the general opinion if you aren't already used to some other tool, try Kicad. I got up and running with Kicad using this tutorial - https://contextualelectronics.com/learning/getting-to...
by IanS
Sat Jan 21, 2017 10:43 pm
Forum: acorn atom
Topic: Prime's ROM/RAM board
Replies: 14
Views: 961

Re: Prime's ROM/RAM board

Have you asked Prime?
by IanS
Wed Jan 18, 2017 6:35 pm
Forum: for sale / freebies
Topic: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro
Replies: 595
Views: 44615

Re: Offered: Matchbox sized 6502 / Z80 / 6809 Co Pro

flynnjs wrote:Just a little update. All the construction was done and I'm just programming and testing. Hope to post out by weekend.

Is it easier to bring mine along to the Abug meet?
by IanS
Fri Jan 06, 2017 11:48 pm
Forum: past events & exhibitions
Topic: May 12th-14th 2017 Cambridge ABUG (FULL) & Acorn World event at CCfCH
Replies: 189
Views: 9312

Re: May 12th-14th 2017 Cambridge ABUG & Acorn World event at CCfCH

Fantastic, it was great last time. Stick me down when you start a list. Maybe try a different restaurant for the evening meal. I don't think I have any Acorn gear or artifacts that the centre won't have, other than an Acorn Umbrella, but it looks a bit manky as it has spent the last two decades roll...
by IanS
Fri Jan 06, 2017 11:34 pm
Forum: past events & exhibitions
Topic: ABug North 18/19/20 November 2016, Bolton
Replies: 199
Views: 10753

Re: ABug North 18/19/20 November 2016, Bolton

If anyone I bored at Bolton with pictures of the Atom Econet PCB I'd had made at OSH Park was interested in how they turned out, they arrived in the post today. It works :D :D :D If I did it again, I'd change a few things, but it didn't require any bodge wires, so I'm happy. IMG_20161130_203138584_...
by IanS
Mon Jan 02, 2017 2:19 pm
Forum: hardware
Topic: Econet pinout
Replies: 9
Views: 552

Re: Econet pinout

flynnjs wrote:
IanS wrote:So whilst the 5-pin din pin 3 is the clock+ in diagrams and socket boxes, it's actually the polarity of clock- signal which is used by the ADLC.


Not all diagrams:

I should have been clearer, I wasn't referring to circuit diagrams.
by IanS
Sun Jan 01, 2017 8:08 pm
Forum: hardware
Topic: Econet pinout
Replies: 9
Views: 552

Re: Econet pinout

It looks like whoever made this econet add-on for the beeb got confused by the pinout and have swapped the clock signals over. http://beebmaster.co.uk/Econet/BBCBSpEc.html
http://beebmaster.co.uk/Econet/SpEconet13.html
Pin 5 of the Econet module doesn't go to the outer pin of the din socket.
by IanS
Sun Jan 01, 2017 8:00 pm
Forum: hardware
Topic: Econet pinout
Replies: 9
Views: 552

Re: Econet pinout

I guess Acorn got in a mess with this and had already had socket boxes made which referred to pin 3 as clock+, even though the clock- signal is what actually gets to the ADLC chip. Or they just decided the positive pins looked better on the outer pins, maybe they thought it was easier to remember. T...

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