Here are some scans of the Barson computers Electron Econet interface CCT and blank board

discuss both original and modern hardware for the bbc micro/electron
awilliams
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Here are some scans of the Barson computers Electron Econet interface CCT and blank board

Post by awilliams » Tue Jun 23, 2020 2:51 pm

The attached zip contains scans of the circuit and un populated PCB for an Acorn Electron Econet interface.

I was told this design does not work in all screen modes as the CPU gets halted for too long during the video DMA there being only half the bus bandwidth in the electron compared to the BBC.

I believe the inscription ROKNAL on the PCB referes to the designers as Ron Drewet ad Karl Hradsky.

Sorry the site would not accept a 17meg zip so the files are now attached. Actually the hires mono scans of the board and two halves of he circuit scanned in TIFF didn't up load either.

Oh well probably enough did to get the idea.
AcornElectronEconetInterfaceBlankPCBcolourTopSide.JPG
AcornElectronEconetInterfaceBlankPCBcolourBottomSide.JPG
Screen Shot Circuit one piece pm.png

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Re: Here are some scans of the Barson computers Electron Econet interface CCT and blank board

Post by daveejhitchins » Wed Jun 24, 2020 9:07 am

awilliams wrote:
Tue Jun 23, 2020 2:51 pm
The attached zip contains scans of the circuit and un populated PCB for an Acorn Electron Econet interface.

I was told this design does not work in all screen modes as the CPU gets halted for too long during the video DMA there being only half the bus bandwidth in the electron compared to the BBC.

I believe the inscription ROKNAL on the PCB referes to the designers as Ron Drewet ad Karl Hradsky.

Sorry the site would not accept a 17meg zip so the files are now attached. Actually the hires mono scans of the board and two halves of he circuit scanned in TIFF didn't up load either.

Oh well probably enough did to get the idea.

AcornElectronEconetInterfaceBlankPCBcolourTopSide.JPG
AcornElectronEconetInterfaceBlankPCBcolourBottomSide.JPG
Screen Shot Circuit one piece pm.png
Woooooooow! Hens teeth / Rocking horse muck . . . Absolutely brilliant =D>

I didn't think we would EVER see the details of this board :mrgreen:

Would it be possible to put the files into, say, DropBox? Then we could download them from there?

Had a very quick scan of the schematic and it only seems to take signals from the Cartridge socket - So it could possibly fit into a large external cartridge.

I'm stuffed for project time, at the moment, so hopefully someone else would have the time to do something with this. Maybe pop all the glue-logic into a PLD/CPLD?

A very chuffed Dave H :mrgreen:

Edit: Regarding the Mode issue: I'm sure that can be overcome - and there's always the MRB, Basic ULA and UEU :D

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Re: Here are some scans of the Barson computers Electron Econet interface CCT and blank board

Post by daveejhitchins » Wed Jun 24, 2020 9:27 am

Looks like we'll have to use the schematic with a copy of the PCB as at least one BUS signal isn't labeled: Pin 12 IC10 . . .

More later.

Dave H :D

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Re: Here are some scans of the Barson computers Electron Econet interface CCT and blank board

Post by BeebMaster » Wed Jun 24, 2020 3:58 pm

Well well! The Elkonet comes a step closer!
Image

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Re: Here are some scans of the Barson computers Electron Econet interface CCT and blank board

Post by johnkenyon » Wed Jun 24, 2020 6:30 pm

No collision detection I note.
The circuit between the 68B54 and the Econet socket is more or less a direct lift from the original ("issue 1") Master Econet module.

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Re: Here are some scans of the Barson computers Electron Econet interface CCT and blank board

Post by IanS » Wed Jun 24, 2020 6:37 pm

johnkenyon wrote:
Wed Jun 24, 2020 6:30 pm
No collision detection I note.
The circuit between the 68B54 and the Econet socket is more or less a direct lift from the original ("issue 1") Master Econet module.
Looks more like the bridge, as it uses 26ls34 recievers, rather than the usual lm319 comparators.

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Re: Here are some scans of the Barson computers Electron Econet interface CCT and blank board

Post by daveejhitchins » Wed Jun 24, 2020 7:46 pm

IanS wrote:
Wed Jun 24, 2020 6:37 pm
johnkenyon wrote:
Wed Jun 24, 2020 6:30 pm
No collision detection I note.
The circuit between the 68B54 and the Econet socket is more or less a direct lift from the original ("issue 1") Master Econet module.
Looks more like the bridge, as it uses 26ls34 recievers, rather than the usual lm319 comparators.
I'm sure all that can be put-right once we get into it!

Dave H :D

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Re: Here are some scans of the Barson computers Electron Econet interface CCT and blank board

Post by myelin » Wed Jun 24, 2020 11:35 pm

If it helps, I did a modern board in the Master/Archimedes Econet form factor that has all the collision detect circuitry in it. It's designed for a microcontroller plus CPLD rather than the usual HDLC, but it might be a good starting point...

https://github.com/google/myelin-acorn- ... om_scratch
SW/EE from New Zealand, now in Mountain View, CA, making BBC/Electron hardware projects for fun.
Most interesting: Arcflash, FX2+PiTubeDirect Tube/Cartridge adapter, USB cart interface.

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Re: Here are some scans of the Barson computers Electron Econet interface CCT and blank board

Post by jgharston » Thu Jun 25, 2020 12:50 am

daveejhitchins wrote:
Wed Jun 24, 2020 9:07 am
Edit: Regarding the Mode issue: I'm sure that can be overcome - and there's always the MRB, Basic ULA and UEU :D
The issue was that the Electron high-res screen didn't leave enough clock cycles to deal with network interupts. Somebody did an update to the NetRx code to swap to a low-resolution mode during data transfers. From memory, it' also a reason for the 'Blank Palette' OSBYTE call.

Code: Select all

$ bbcbasic
PDP11 BBC BASIC IV Version 0.32
(C) Copyright J.G.Harston 1989,2005-2020
>_

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Re: Here are some scans of the Barson computers Electron Econet interface CCT and blank board

Post by awilliams » Thu Jun 25, 2020 2:36 am

The highe res scans can be found found here. (It was still syncing at the time I posted here so hopefully that will be done by the time anybody gets back here. I don' guarantee the longevity of the drop box folder so archiving this data somewhere else as well would be a good idea.

https://www.dropbox.com/sh/xaj9c8sz0vfx ... S6x5a?dl=0

Other things about this. A vertical piece of double sided striped PCB was soldered to at right angles with a bunch of individual wires to form the connector. The board was then fitted into one of the PLUS xx boxes the one with just the cartridge slots. I don't remember if its number. The 'connector' PCB fitted into one of the cartridge slot sockets, there was a bit of the case nibbled out in the opposite corner to expose the din socket.

Alan

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Re: Here are some scans of the Barson computers Electron Econet interface CCT and blank board

Post by awilliams » Thu Jun 25, 2020 2:42 am

I forgot.
the pcb goes in the PLUS x case upside-down with the components downward and thus the back of the pcb is against the top inside of the case .

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Re: Here are some scans of the Barson computers Electron Econet interface CCT and blank board

Post by mr-macrisc » Thu Jun 25, 2020 3:07 am

Nice,

Messaged a while back asking if he could maybe scan the board (I see how he can’t reply) least we have the scans which by sounds of it may make it reasonably doable to have a cartridge that will do econet or take a master/a3000 module.

Brilliant.

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Re: Here are some scans of the Barson computers Electron Econet interface CCT and blank board

Post by richardtoohey » Thu Jun 25, 2020 3:27 am

daveejhitchins wrote:
Wed Jun 24, 2020 9:07 am
Woooooooow! Hens teeth / Rocking horse muck . . . Absolutely brilliant =D>
@awilliams: I'm not entirely sure but I think Dave is really pleased you posted this. :wink:

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Re: Here are some scans of the Barson computers Electron Econet interface CCT and blank board

Post by awilliams » Thu Jun 25, 2020 5:07 am

mr-macrisc wrote:
Thu Jun 25, 2020 3:07 am

Messaged a while back asking if he could maybe scan the board (I see how he can’t reply)
Yes sorry about that. I have been meaning to upload the scans since then & well since I made my scanner work again.

I haven't figured out the IM business yet, getting that privilege doesn't seem to have any correlation with the apparent value of ones contributions. So stick with the email in the footer I think, I have no way of replying otherwise.

Alan

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Re: Here are some scans of the Barson computers Electron Econet interface CCT and blank board

Post by richardtoohey » Thu Jun 25, 2020 5:49 am

awilliams wrote:
Thu Jun 25, 2020 5:07 am
I haven't figured out the IM business yet, getting that privilege doesn't seem to have any correlation with the apparent value of ones contributions. So stick with the email in the footer I think, I have no way of replying otherwise.
Do you mean the PMs - private messages? You can receive them after something like 10 posts and send/reply after either 20 or 25 posts - so I think you might just have hit that threshold with your last post. If you are meaning something else then :oops: please ignore!

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Re: Here are some scans of the Barson computers Electron Econet interface CCT and blank board

Post by danielj » Thu Jun 25, 2020 6:56 am

awilliams wrote:
Thu Jun 25, 2020 5:07 am
I haven't figured out the IM business yet, getting that privilege doesn't seem to have any correlation with the apparent value of ones contributions. So stick with the email in the footer I think, I have no way of replying otherwise.
It's 25 posts and they activate automatically. We will usually happily activate them manually for anyone that asks! It has nothing to do with any value of contributions, it was put in place before my time to put off scammers.

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Re: Here are some scans of the Barson computers Electron Econet interface CCT and blank board

Post by awilliams » Thu Jun 25, 2020 1:22 pm

It's 25 posts and they activate automatically. We will usually happily activate them manually for anyone that asks! It has nothing to do with any value of contributions, it was put in place before my time to put off scammers.
Ah ok thank you, I did mean PM not IM. & it does look like I have reached 25 posts anyway.

The other thing I would add is that regarding the collision detection circuit I don't think there is that much point in bothering for two reasons. Firstly without the circuit collisions will still be detected by bad crc values, secondly on a modern Econet with a few machines there is really very little cause for collisions. On a heavily loaded net with bridges, multiple file servers, and dozens of machines early collision detection might have saved a bit of bandwidth, but I don't think its worth the effort today.

At best all I have these days is a RISCPC, A540, R260, Beeb,M128,Compact, Bridge, two Filestores presently dead, an Ecolink with a slight possibility of a motherboard with an ISA slot, and an A4 with a dead psu. It would be rare that I would use more than any two device at one time and there is never more than one user. If I get round to building any new Econet devices I would not bother with the collision detection. In reality its the RISC PC and the BBC that get used together.

Alan
Last edited by danielj on Thu Jun 25, 2020 3:51 pm, edited 1 time in total.
Reason: Tidying up quoting

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Re: Here are some scans of the Barson computers Electron Econet interface CCT and blank board

Post by tone76 » Thu Jun 25, 2020 3:08 pm

YES!! Thank you!!

I'm in the process of making a video about using an Acorn Electron in Australia, and I was hoping to mention the Barson Econet adapter as part of this video. I recall reading about it in computer magazines of the period, but I haven't had a chance to revisit those mags just yet.

There's also a whole bunch of other Aussie Acorn-related stuff I'm trying to gather up and put into a video so that it's documented for the ages, but it's been slow going. Partially due to libraries being closed (and only just recently reopening), and partially because I haven't had a lot of time to follow a couple of leads ... but this is super helpful. Thanks again for sharing this scan.
Last edited by tone76 on Fri Jun 26, 2020 11:47 pm, edited 1 time in total.
Acorn Electron
BBC Model B (either too many or not enough)
BBC Model B+ 128K
BBC Master 128 x 2

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Re: Here are some scans of the Barson computers Electron Econet interface CCT and blank boards jk l lop

Post by mr-macrisc » Fri Jun 26, 2020 9:10 am

You got some measurements of board.

Also anyone recommend some software i can have a play with and see if can produce a full circuit diagram of the board :)

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Re: Here are some scans of the Barson computers Electron Econet interface CCT and blank board

Post by danielj » Fri Jun 26, 2020 9:17 am

KiCad:
https://kicad-pcb.org/

Lots of tutorials around the web.

(although I would seriously consider starting with something a bit more straightforward!)

d.

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Re: Here are some scans of the Barson computers Electron Econet interface CCT and blank boards jk l lop

Post by daveejhitchins » Fri Jun 26, 2020 10:54 am

mr-macrisc wrote:
Fri Jun 26, 2020 9:10 am
You got some measurements of board.

Also anyone recommend some software i can have a play with and see if can produce a full circuit diagram of the board :)
Before you start, please read my post here.

Dave H :D

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Re: Here are some scans of the Barson computers Electron Econet interface CCT and blank board

Post by Marvin » Fri Jun 26, 2020 11:21 am

As far as I can tell this is a complete list of the components on the Barson Econet interface, IC15 isn't labelled on the diagram but I suspect its a 74LS244 as both the B and B+ use this chip (IC96 & IC80 respectively) to set station ID and use the same value resister pack & link setup..

Is there a copy of the ROM contents anywhere ? I guess it's a version of NFS ?

Code: Select all

IC1		74LS133
IC2		74LS04
IC3		74LS04
IC4		74LS32
IC5		74LS00
IC6		26LS30
IC7		74LS27
IC8		16K ROM
IC9		68B54
IC10		74LS74
IC11		74LS123
IC12		26LS34
IC13		74LS10
IC14		74LS30
IC15		?
IC16		74LS163
IC17		74LS74
IC18		74LS00

Q1		BC239
Q2		BC239

RN1		8x22K
R1		3.3K
R2		220K
R3		3.3K
R4		39K
R5		12K
R6		12K
R7		12K
R8		12K
R9		2.2K
R10		2.2K
R11		10K

C		47nF Decoupling Caps (x13)
C1		10uF 16V Elect
C2		47uF
C3		2.2uF

SK1		To fit Cartridge Slot (Piece of PCB ?)
SK2		Econet Socket

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Re: Here are some scans of the Barson computers Electron Econet interface CCT and blank boards jk l lop

Post by mr-macrisc » Fri Jun 26, 2020 5:59 pm

daveejhitchins wrote:
Fri Jun 26, 2020 10:54 am
mr-macrisc wrote:
Fri Jun 26, 2020 9:10 am
You got some measurements of board.

Also anyone recommend some software i can have a play with and see if can produce a full circuit diagram of the board :)
Before you start, please read my post here.

Dave H :D
They didn’t work cos of the screen mode contention but I believe that has workarounds that others solved. Another solver of that may be 64k Master ram mode. Also maybe UEU may have uncontended modes potentially?

At moment I just thought it may be cool to pop the design as it stands into a board design package (we could maybe make a couple up as they aren’t complex) but having the design laid out electronically may be useful for others who want to use
A module in cartridge.

I did enquire if this board was available so I could make up the interface but think it may be destined to computer museum so may just get a board made. Be good practise for my soldering skills :)

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Re: Here are some scans of the Barson computers Electron Econet interface CCT and blank boards jk l lop

Post by daveejhitchins » Fri Jun 26, 2020 6:58 pm

mr-macrisc wrote:
Fri Jun 26, 2020 5:59 pm
daveejhitchins wrote:
Fri Jun 26, 2020 10:54 am
mr-macrisc wrote:
Fri Jun 26, 2020 9:10 am
You got some measurements of board.

Also anyone recommend some software i can have a play with and see if can produce a full circuit diagram of the board :)
Before you start, please read my post here.

Dave H :D
They didn’t work cos of the screen mode contention but I believe that has workarounds that others solved. Another solver of that may be 64k Master ram mode. Also maybe UEU may have uncontended modes potentially?

At moment I just thought it may be cool to pop the design as it stands into a board design package (we could maybe make a couple up as they aren’t complex) but having the design laid out electronically may be useful for others who want to use
A module in cartridge.

I did enquire if this board was available so I could make up the interface but think it may be destined to computer museum so may just get a board made. Be good practise for my soldering skills :)
Hope you haven't an AP6 installed? #-o

Dave H :lol:

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Re: Here are some scans of the Barson computers Electron Econet interface CCT and blank board

Post by danielj » Fri Jun 26, 2020 7:15 pm

Indeed! :) If you're going to make one of these, make it as a cartridge. so you don't have to cut holes in your plus 1 and can still use both cartridge slots.

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Re: Here are some scans of the Barson computers Electron Econet interface CCT and blank boards jk l lop

Post by mr-macrisc » Fri Jun 26, 2020 8:27 pm

daveejhitchins wrote:
Fri Jun 26, 2020 6:58 pm
mr-macrisc wrote:
Fri Jun 26, 2020 5:59 pm
daveejhitchins wrote:
Fri Jun 26, 2020 10:54 am

Before you start, please read my post here.

Dave H :D
They didn’t work cos of the screen mode contention but I believe that has workarounds that others solved. Another solver of that may be 64k Master ram mode. Also maybe UEU may have uncontended modes potentially?

At moment I just thought it may be cool to pop the design as it stands into a board design package (we could maybe make a couple up as they aren’t complex) but having the design laid out electronically may be useful for others who want to use
A module in cartridge.

I did enquire if this board was available so I could make up the interface but think it may be destined to computer museum so may just get a board made. Be good practise for my soldering skills :)
Hope you haven't an AP6 installed? #-o

Dave H :lol:
Only in one of my plus 1’s :)

And again first port of call was to do circuit diagram.

Maybe cartridge is a better idea.

Anyone got recommendation for circuit software?

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Re: Here are some scans of the Barson computers Electron Econet interface CCT and blank board

Post by walkerworks » Sat Jun 27, 2020 10:45 am

mr-macrisc wrote:
Fri Jun 26, 2020 8:27 pm
And again first port of call was to do circuit diagram.

Maybe cartridge is a better idea.

Anyone got recommendation for circuit software?
Have a look at EasyEDA, it's an online designer and is simple to use and has extensive part libraries. Just be careful if you use User supplied parts though..

Derek
bygonebytes.co.uk

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Re: Here are some scans of the Barson computers Electron Econet interface CCT and blank board

Post by BeebMaster » Sat Jun 27, 2020 11:16 am

There are some pictures here of an actual living one mounted inside a Plus 1:

http://www.beebmaster.co.uk/Econet/ElkNet.html
Image

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Re: Here are some scans of the Barson computers Electron Econet interface CCT and blank board

Post by awilliams » Sat Jun 27, 2020 2:16 pm

tone76 wrote:
Thu Jun 25, 2020 3:08 pm
YES!! Thank you!!

I'm in the process of making a video about using an Acorn Electron in Australia, and I was hoping to mention the Barson Econet adapter as part of this video. I recall reading about it in computer magazines of the period, but I haven't had a chance to revisit those mags just yet.

There's also a whole bunch of other Aussie Acorn-related stuff I'm trying to gather up and put into a video so that it's documented for the ages, but it's been slow going. Partially due to libraries being closed (and only just recently reopening), and partially because I haven't had a lot of time to follow a couple of leads ... but this is super helpful. Thanks again for sharing this scan.
Unfortunately I have just given away most of my stuff that would be in this category. I will ask the recipient when I next see him if he minds doing photos.

Most of the things I had were the work of Northgate computing, or Intertech both in Adelaide. The devices I know of are:
1. Clone of the issue 1 econet module notable for not having a solder mask.
2. Low profile M128 cartridge ROM board, could be fitted inside the M128 and could not be removed by the user also lacking a solder mask.
3. Clone of the A series backplane for A310 etc
4. BBC userport buffer box from Intertech (Earl Rowan comes to mind)
5. I think Northgate did a clock box too but I don't have one.
6. Northgate and maybe others cloned the 1MhzE bus host adaptor
7. Computerlec in Seaford Melbourne did a clock box, I may have one it was mounted in a clipsal wall plate. (It was lousy, I added a PAL to most of the ones I saw to get adjustable mark/space ratios)
8. Everybody ripped off the Hard disk system and boxed their own host adaptor (commonly) + ACB4050/4070+ MFM driver of various sizes + apple 2 power supply. (I don't have one any more, I have the only actual Acorn one I ever saw here)
9. Barson ripped of the Eurocard System 4 fileserver though all the cards were Acorn the case was identical the PSU was local and linear. Mine has coke can sized capacitors with Ellistronics price stickers.
That's all I can remember without putting my mind to it seriously.

I may do photos of the things I still have if there is any interest.

I remember hearing of some enterprising individuals in Perth who had a project to clone the whole Beeb, the Australian market was awash with Apple 2 clones at the time so it wasn't surprising. It fell over because it turned out that some licensing issue between Acorn and Watford Electronics meant that Watford could only sell their DFS including parts presumably the tube host code licensed from Acorn, for Acorn machines, and thus not dodgy antipodean clones. I don't imagine it would have got a lot further before Acorn put a stop to them but it was pretty audacious.

Back to the topic at hand.
I have measured the original board. Starting with the board face up, movingly clockwise as close as I can say the lengths in mm of the sides are more or less as follows: 300, 78.7, 160, 48, 140, 30.5. Interestingly you don't get back to the start by 0.3 of a mm.

Alan

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Re: Here are some scans of the Barson computers Electron Econet interface CCT and blank board

Post by awilliams » Sat Jun 27, 2020 2:22 pm

I can't imagine that I have a ROM for this but, I have tubes and tubes of the things so I will check just in case.

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