Thursday, October 9, 2014

Vintage Computer - the first portable computer at 200 lbs - Autonetics Recomp 501 (1958)

                  Click photo to enlarge
info click
Bugbook Historical Microcomputer Museum
Autonetics Recomp 501 digital computer
The Autonetics Recomp 501 is also the very first commercial transistor digital computer. Autonetics computer is now displayed in our museum.  We moved the computer from the warehouse into the museum to help show the time line of computing before the microcomputer revolution.  This computer is serial # 003 & some components in it are date coded 1958 - this may be the earliest transistor digital computer in any a museum.  We are  delighted to have it -- WOW it is small but very heavy - about 200 lbs.

Autonetics Recomp 501 digital computer, bugbook
Autonetics Recomp computer in museum
The computer looks good with all the cards exposed - here it is in the museum.  The size is about 30 inch's high & 40 inch's in length.

It looks like a nice piece of art with all the cards, gold connectors and 1000's of wires connecting the cards.

    David tells about the Autonetics computer he acquired 25 years ago.                                                                                                                                                                                                                                                                                                                         Click on photo to enlarge
Bugbook Historical micrcomputer Museum
1958 ad for first 200 lb transistor computer
 This has to be the very first advertisement for a portable computer -about 1958. Look at the photo and see the two fellows carrying this 200 lb computer onto a construction site – WOW what a imagination. This computer is very heavy and these fellows are carrying it like it is only  30 lbs.
Here is some text from the advertisement.

200 lb computer – Portable Digital Computer that can solve your problems where they happen.

It may be a highway construction job --- oil exploration --- and aerial exploration. Where ever your problems happen – in the field – office – or lab.


Here is one side panel with the PC cards. It is built very solid and must have taken a very long time to build by hand.

David Larsen, kk4ww,bugbook,
Autonetics Recomp 501 digital computer

There must be at least 1000 wires in the backplane - all white. Building this computer required lots of Advil. This photo shows only a small part of the wiring.

David Larsen, kk4ww,bugbook,
Autonetics Recomp computer 

Drum memory - looks like the all the registers as well as the data are on this form of memory - ie Accumulator - the instructions were executed serially so this is a very slow computer. 

Autonetics Recomp 501 digital computer

Archive photograph - full operational setup.  This photo takes away the idea that this is a portable computer.

Here is link to another Autonetics computer that I worked on in 1960 and the Recomp computer supplied many ideas for this ICBM computer.

A good look at the RECOMP-11 photo album  "CLICK" 

A few references for the seriously interested - a service manual and more.

More photos and information about our Autonetics computer.

Recomp service manual - just in the event you have one and need to get it running.

This list claims the Recomp is the 118th type of digital computer every made

David Larsen
I have had this computer in my collection for 25 years or more and wish I had records of where it came from. I just remember it being in a corner with about 10 or so minicomputers. Most of the minicomputers have gone out to other collectors like Bob Rosenbloom 


  1. Wow, thank you for keeping history alive, we have to know where we came from, to show us where we need to go. Some of these computers, I am sure helped build America, calculated freeways, missle development t and who knows, maybe the moon. Thanks again.

    1. Hi Matt - Thank you for the nice comment - I do enjoy writing about this old stuff and also having many of the items in my museum. I will be giving a tour of the museum tomorrow to a great grandson who is in the 9th grade - some of his friends found my videos and were so excited that he was part of the family. My grandson and great grandson are really into the newest computer ideas. I do my best to keep. Come to Floyd Virginia for a visit and I will give you a tour of the museum - Dave Larsen KK4WW at N4USA


I look forward to your comments and will respond.