Computer History: Librascope LGP-30 Computer (General Precision, CDC, personal minicomputer) 1956

[@Telcom100]

We had the transistorized version LGP-21 in our high school computer club in the early 60s. The whole computer was designed around the drum memory. Even the registers were stored on the drum and brought to the one bit adder a bit at a time as the drum rotated and the results written back to the drum as it rotated. Very simple architecture, although very slow as everything was done a bit at a time.

[@douro20]

The running machine shown briefly is in the collection of the University of Stuttgart. It is the only fully working one I know of. I understand it is quite a reliable machine, owing to its use of primarily silicon diodes in its logic. Due to the bit-serial nature of the architecture it is quite slow, even to 1950s standards, but its 31-bit precision made it a very good machine for scientific problems.

[@ComputerHistoryArchivesProject]

Hi douro20, yes, I think you are correct. That's the only LGP-30 fully working as far as we know too. Quite unique!

[@Madness832]

That's one Hell of a hard disk @ 4:02!

[@ComputerHistoryArchivesProject]

@Madness832, yes, it is quite a huge disk! The Librascope company produced some amazing things, and many of them have faded into history. It feels great to bring some of these thinks back into the light. ~ Thanks for watching and for your comments, too! ~ CHAP

[@LionheartNh]

Those weasley HDD and SSD you have in your computers are not drives....that's a drive.

[@zaugitude]

125 mb! Huge amount of storage for a single device at the time for sure.

[@zaugitude]

Also, the spinning disks would have an edge speed of over 2200 inches per second; must have been a bit scary to be near a running unit. Would be great to hear audio of one.

[@michaelmoorrees3585]

I use to drive by Librascope every once in a while. More Often, did I drive by the Burroughs (Electro Data) facility, but did not think about it too much. Many of my relatives worked at that Burroughs facility. Both Librascope, and Electro Data, were bought out by larger companies. CDC for Librascope & Burroughs for Electro Data. I think Librascope was latter sold to Singer.

[@lwilton]

And two blocks away from their head office was a small building with the name "WED Enterprises". It's still there, these days called WDI, and has almost every building in the whole area.

[@drboze6781]

4:02 - Well, that beats my first hard drive, a 40MB Miniscribe. Might have cost more, though, but I'm sure it was a lot quieter! Oh, I just noticed, I'm also circa 1965!

[@drboze6781]

That warehouse trove was like finding Tutankhamen's tomb, computer-history wise!

[@geo48geo48]

There is a working LGP 30 in germany.

[@Andy_Holmes]

That's funny how it was considered a desktop computer.

[@dave1135]

Well, it WAS the desktop. Lol

[@william2william]

It was called a desk computer, not a desktop computer, because it was the size of a desk.

[@dave1135]

I wonder how hot that thing got, with all those vacuum tubes

[@sx642]

Well according to the spec's it used 1500 Watts. Nice and toasty :)

[@lwilton]

@@sx642 1500W is amazingly small. That is the size of a small room heater you can get from Lowes for forty bucks. You could easily run it off a single standard 110V wall plug. Most computers on those days took dedicated power, and a lot of it.

[@dale116dot7]

For a computer, it’s a very small number of vacuum tubes. One bit at a time.

[@linofe9667]

For the technology of 50es was small.

[@PINKBOY1006]

Theres a really good video with this computer running that I found a long time ago. Really shows how good these “desktop” computers were at the time. kzbin.info/www/bejne/bYjEioyEiqiKg7s