UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Computers

Notices

Vintage Computers Any vintage computer systems, calculators, video games etc., but with an emphasis on 1980s and earlier equipment.

Closed Thread
 
Thread Tools
Old 6th May 2004, 8:50 pm   #1
Sam
Hexode
 
Sam's Avatar
 
Join Date: Apr 2003
Location: Higham-on-the-Hill, Leicestershire, UK.
Posts: 338
Default Vacuum Tube Logic

Took a bit of deliberation, but I think this is an 'Everything Else' topic! (Prepare to tell me I'm wrong, and it should have gone in the 'Vintage Computers' section!)

This is one of my recurring thoughts in Digital Electronics Lectures and Revision. Were there ever Vacuum Tube implementations for the Boolean Logic functions (NOT, OR, AND, etc)? It is a thought that popps into my mind every so often. Someone better suited to all this digital stuff could work the circuits out I'm sure, but I would much rather be told it has been done for me

If anyone knows if they exist, I would like to see some of the circuits. Or were all early valved computers analogue ones?

Idle thoughts over, best get back to the real world!

Sam
__________________
Can he lead a Normal life, Doctor?
No, he will be ... an Engineer.
Sam is offline  
Old 6th May 2004, 8:56 pm   #2
jim_beacon
Retired Dormant Member
 
jim_beacon's Avatar
 
Join Date: Mar 2003
Location: Bishop's Waltham, Hants, UK.
Posts: 939
Default Re: Vacuum Tube Logic

Sam,

yes the logic functions were implemented with valves, as were registers and counters - you do sometimes come across them in old test equipment, especially teleprinter test gear. Also look at the input circuits of scope for multivibrators.

Some of the counting circuits used special valves (dekatrons, for example), and a great deal of use was made of thyratrons (though only for very low speed stuff - they won't work reliably above about 15KHz, look at all the problems with early TV timebases!).

There were also valve op-amps. I have some somewhere that use two double triodes, with the bases and associated components mounted on an octal plug.

Jim.
jim_beacon is offline  
Old 6th May 2004, 9:40 pm   #3
ppppenguin
Retired Dormant Member
 
ppppenguin's Avatar
 
Join Date: Dec 2003
Location: North London, UK.
Posts: 6,168
Default Re: Vacuum Tube Logic

There were a number of digital computers made with valve logic. Starting with Colossus. Then ENIAC and EDSAC in the USA, various early machines in the UK. The early versions of the Leo made by the Lyons company, all the early IBM machines. Ferranti Pegasus.

I'm not an expert on the subject - these are the ones that come immediately to mind. There were probably more.

Plus all the valve logic in TV studio equipment from the 1930s to the early 1960s. Used mainly for complex pulse generation.
ppppenguin is offline  
Old 6th May 2004, 9:50 pm   #4
jim_beacon
Retired Dormant Member
 
jim_beacon's Avatar
 
Join Date: Mar 2003
Location: Bishop's Waltham, Hants, UK.
Posts: 939
Default Re: Vacuum Tube Logic

you can try here for a valve based calculator (OK so there cold cathode thyratrons, but there still glass....)

http://www.oldcalculatormuseum.com/anitaC-VIII.html

ther's lots of other interesting stuff on this site aswell.

Jim.
jim_beacon is offline  
Old 7th May 2004, 12:25 am   #5
joe
Rest in Peace
 
joe's Avatar
 
Join Date: Apr 2003
Location: Edgware, North London.
Posts: 307
Default Re: Vacuum Tube Logic

Hi Sam

In 1962 I started working for Elliot Automation who had just ventured into solid state computers ( mainly germanium!) and as a result there were loads of scrap modules left lying around from their first generation machines, each module about A5 size with either 2 or 4 double triodes.

As Jeffery pointed out there were others including the Ferranti Pegasus, one of which was installed in my old college (now City University). I was not involved with it , but I do remember venturing into the room out of curiosity & thinking " Its a bit warm in here! "

Joe
joe is offline  
Old 7th May 2004, 7:52 am   #6
ppppenguin
Retired Dormant Member
 
ppppenguin's Avatar
 
Join Date: Dec 2003
Location: North London, UK.
Posts: 6,168
Default Re: Vacuum Tube Logic

The Pegasus was a very advanced design for its day. It did not need an air conditioned room because the cabinets themselves were cooled, albeit by external plant. Somebody I know did work for the ill starred Blue Streak missile on a Pegasus. He sometimes claims that it was his work that caused the project to fail

A few years ago I went to a meeting at the Science Museum where a Pegasus was due to be demonstrated. About 20 minutes before the demo the machine decided to give trouble
ppppenguin is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 3:30 am.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.