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Bassoonbloke
March 2nd, 2007, 07:11 AM
Hello People,

I'm in the UK and have a complete set of circuit boards for a GEC 4070 (1976) Processor unit (All TTL !!) and am hoping to connect the lot together and get a working system. I also have 2 x 32k Magnetic core memory boards (for the minimum 64k) to be useable.
I'm hoping to make my own backplane for this system (i have pictures of the original, which will help).
So....... my question is, is anyone on this forum familiar with this old mini, or does anyone have any technical info that they could pass onto me as i'm after anything possible for help.

Thanks very much,

Alan.

Bassoonbloke
March 6th, 2007, 07:15 AM
Hello there,

Just incase anyone is interested. This is a piccy of a GEC 4070, complete and working in the mid 70's.
I only have all the panels for the main processor unit (approx 15 boards) and one storage unit (2 x 32k Core memory boards and interface and terminator boards). I also have the large connector lead to go from processor to storage unit.:cool:
If anyone has any info / parts or any personal experience of this system, i would be very grateful if they could contact me or post stuff on this forum.

Thanks very much,

Alan. :)

Bassoonbloke
March 6th, 2007, 07:18 AM
OK so i forgot to attach the piccy, so here it is.:mrgreen:

nige the hippy
March 6th, 2007, 10:40 AM
Actually I was going to get back to you soon, but wanted to send an email to a name I know, in a town i know, to see if he was the same bloke who I'm pretty sure was the expert on these systems. I haven't sent it yet because I havent found my box of network cards since the house move, and can't get MY pc on line to find the link. I did a google and found a nice picture & recognise the disk drives well as I used to repair minicomputers about 5 yards from a couple. Not absolutely sure about the mainframe though, although it was probably closely related. These particular machines were being maintained well past their sell by date as they were used to run bits of the Underground, and the PC based solution deemed to replace them, wasn't reliable enough.

If you were to chase the company that took over Granada computer services, and formerly CFM at Fenton Stoke-on-Trent They may have service info (less likely the test-bed machine, it was 20 years ago!) It would be marvellous to get your boards going, Loads of Blinkenlights!

Good luck

Bassoonbloke
March 7th, 2007, 01:06 AM
Thanks for the reply Nige,

I have piccys of the backplane (which was actually 3 strips all running side by side. I would really like to get hold of a backplane (obviously !!), but i should be able to hardwire if i have to.
Apparently these were also used by the Prestel folks (the man i bought my boards from still has a complete system, but no tech details or info at all).
If you do come across anything i would very much appreciate it (there is actually very little on the web, i've had a pretty good look).

Cheers,
Alan.:)

Bassoonbloke
April 3rd, 2007, 01:15 AM
Hi Nige,

Did you have any luck contacting your contact (?) about this bit of kit?
I really want to try to hook all the panels that i have together and see if i get any kind of response.

Please let me know how you get on.

Cheers,
Alan.:)

nige the hippy
April 3rd, 2007, 08:50 AM
That's strange! he replied about 10 minutes ago!

it's the right bloke, but he didn't work on that particular machine, however all is not lost, as he has passed me on to "Flash" a very eccentric - but in the best possible way - chap, who may be the right one, He did say that info on that generation of machine was kept Very-Much-in-house. Have you actually tried contacting GEC, it certainly used to be the sort of beaurocratic organisation that would archive everything.

I will keep you informed about flash!

Nig

PS moderators ... should we do this in PM?

Bassoonbloke
May 9th, 2007, 02:59 AM
OK folks,

For anyone who's interested i was recently offered the Processor Crate and Memory storage crate (complete with all panels) of a GEC 4070, in other words all the important bits !! :D (i have to pick it up at the weekend)
I still have no documentation to talk of, but i will hopefully manage to sort something out.
Once i add some power supplies and connect everything up, i should (hopefully) have a fully working system. I need to add some storage and a terminal to see what's going on, but this should be good stuff.
I will post some piccy's as and when i have everything.

Alan.:)

Bassoonbloke
May 18th, 2007, 08:08 AM
Hi Folks,

Well i now have my GEC 4070 processor crate and memory storage box.
I have managed to get the processor fired up and find that i need lots of replacement front panel bulbs.
The attached pictures are the 2 parts in situ, where they worked continuously 24/7 for the last 30 years !! (not bad going eh?)
I will take some piccy's as and when things get going properly.

Enjoy,
Alan.

keedon
July 3rd, 2008, 03:17 PM
Are you still working on this - I used to develop software for these many years ago (my first professional job) and would love to see one working again

Bassoonbloke
July 4th, 2008, 08:01 AM
Hi Keedon,

Yes i am still working on this, and am still trawling for any and all information that anyone can pass onto me.
I have the processor and memory crates powered up and linked up. I have run the memory test program from the BMC (via the front panel keys), and am looking to get a better program (entered via keys as i have no terminal of any kind at the moment) up and running.
I have 512k of ram in the memory crate at the minute (this cost RAL a small fortune), but would like to replace this with the 128k of core memory that i have (the core memory boards are what got me involved in this whole adventure).
I would be very interested in knowing what you were doing on these computers (and how much you still remember!), especially if you would'nt mind passing some of it on.
Thanks for your interest,
Cheers,

Alan.

nige the hippy
July 17th, 2008, 04:39 AM
Bit of a coalescing of "vintage computers in the wild" and this thread...

I sent some emails off regarding the london underground's signalling computers, and joined "district dave's LU" forum.
Questions posted as below....

http://districtdave.proboards39.com/index.cgi?action=display&board=Signals&thread=8284&page=1

And the aformentioned link to "Daddy Bear" & "Mummy bear"....

http://districtdave.proboards39.com/index.cgi?board=Signals&action=display&thread=1473

A pair of GEC 4000 series STILL IN USE!!!!!

Bassoonbloke
July 17th, 2008, 05:13 AM
Hi Nige,

Thanks for remembering this link. The sites are really interesting, and it's amazing that the underground are still using these computers :o. My complete (?) system came from RAL( http://www.isis.rl.ac.uk/isis2004/review/isisfacilityanni.html ) where it was apparently in use for 30 years 24/7, so it did'nt do too badly before it was finally replaced by a couple of 286 pc's :(.
I also own a complete set of spare cards for the system that came from one of the PRESTEL ( http://en.wikipedia.org/wiki/Prestel ) systems. The core memory boards i have also came from the Prestel system (and may still have an OS and program waiting to run again! :).

Cheers,
Alan :D.

nige the hippy
July 17th, 2008, 07:30 AM
Have you a tape drive like the one in the picture? if so is it made by "digi-data corporation"?
If so I have a spare aluminium plate, 1 (sadly only 1) motor, a couple of hubs and idlers you're welcome to.

Bassoonbloke
July 17th, 2008, 11:20 AM
Hi Nige,

Unfortunately i don't have a tape drive :(. I literally only have the processor and memory crate, and some power supplies to get things working. I was offered the original power supply crate as well, but it weighed more than i could handle and switch mode psu's are probably a better bet anyway.
The next time i rig the whole lot together again i will get some piccy's of it going through it's basic memory test (via front keys).

Cheers,
Alan :).

pontus
August 13th, 2008, 02:36 PM
Nice thread. It is cool to see minis other than PDP's :) People tend to care less about them for some reason.

Keep posting pics :)

nige the hippy
August 14th, 2008, 02:26 AM
a recent reply on the London Underground forum says that at least two of the HP 1000s have been recently removed from service (scrapped???:eek:) at Heathrow and Hatton Gardens, will try to find out more.

Bassoonbloke
August 26th, 2008, 07:43 AM
For those of you that might be interested here are a few more pictures of my GEC 4070 Computer. :cool:

Enjoy,
Alan. ;)

pontus
August 26th, 2008, 12:34 PM
Of course :) It looks real nice!

Bassoonbloke
November 20th, 2008, 04:26 AM
Hi Folks,

Been trying to tidy up the PSU's for this old system. The supplies are a bit on the excessive size !!.
The first picture is the Dual 5V 50A main Supply :) - one for CPU crate and one for memory store crate.
The second picture is the Aux PSU, +/- 15v and -5v to feed both crates.
Finally the last picture is of a bunch of cables (actually the Memory crate ones) including the sense wires back from crate to PSU.
Unfortunately i cannot leave the systen connected up all the time, so it's about 20 minutes to connect up and the disconnect when i'm done, still it's all good fun.
Will keep posting stuff that might be of interest.
Comments please,
Cheers,
Alan. :D

pontus
November 20th, 2008, 05:50 AM
Unfortunately i cannot leave the systen connected up all the time, so it's about 20 minutes to connect up and the disconnect when i'm done, still it's all good fun.

I know the feeling. I've been working on restoring a PDP-11/70 and we have to move the cabinets out of storage and connect the memory box and hard drives each time. At least you build some muscle.

Bassoonbloke
November 24th, 2008, 06:59 AM
Hi Pontus,

How about some pictures and info on your system that you are restoring?
I thought i'd post this picture of one of the core memory boards used in the GEC 4000 system computers (it came from a French web site - apologies, i don't have the address to hand), this is just the core array, it should have a large driver board mounted on top. It is 32kb and i have 4 of these which i have yet to try (i'm using their silicon replacement at the minute).
Amazingly the core memory boards may still contain the OS and programs intact when i finally get them installed and powered up :rolleyes:

Cheers,
Alan. :)

nige the hippy
November 24th, 2008, 11:26 AM
Looks like quite a sizeable chunk of ferrite! What capacity is it?

WRT london transport, I did quite a bit of prodding, but no field trip :{(> It looks like the GEC units will be in service a bit longer & HP1000s are being used to keep the rest going.

Bassoonbloke
November 25th, 2008, 01:04 AM
Hello Nige,

Each panel is about A4 size and has 32k on board. So all in all i have 128k's worth, which was very large at the time and extreemly expensive (however at the moment i have 512K of silicon ram fitted - about 10,000 at the time !!). :o
The buying of one of these boards, complete with driver panel from e-bay was the reason i started all of this.
Cheers for the interest.

Alan. :)

pontus
November 25th, 2008, 09:15 AM
Hi Pontus,

How about some pictures and info on your system that you are restoring?



Will do, the project has been dormant for a while. But I'll dig up some pictures later on and post in a new thread.

irrelevant
January 3rd, 2010, 04:00 PM
Sorry to bump an old thread, but did you ever get this up and running - specifically:


Amazingly the core memory boards may still contain the OS and programs intact when i finally get them installed and powered up :rolleyes:

On the off-chance that you did actually have, and still have, a snapshot of the old Prestel software still embedded in there, would there be any way to get it out again? I've been trying to locate anything remaining, software or data-wise, of the old GEC based systems but so far none of the organisations they passed through seem to have any trace remaining. My aim was to get a service back up and running, probably in emulation, using as much of the original software and data as possible. Sadly, there is very little left.

Cheers,

Rob

Bassoonbloke
January 4th, 2010, 07:44 AM
Hi Rob,

First of all, "Happy New Year".
I'm sorry to say that i have nothing in the way of software for this computer system. I have tried installing the 'Core Memory' boards, but their power consumption is much higher than my current PSU's will support (+/- 15V and -5V), so i need to work on these first to have any hope of accessing any possible data still living on the boards themselves.
Like you i also seem to be hitting brick walls when trying to find anything relevant and usefull for these systems (i was lucky to find someone who supplied me with a whole set of boards and took the time to photocopy some of the reference books for me - which was brilliant), but the machines are all but forgotten.
Good luck with your project, and keep us posted if you manage to find anything.

Cheers,
Alan.