Usagi Electric: Restoring old computers

[JCitron]

Restoring old computers and I mean really old computers such as a 1957 Bendix, mid-1970s Centurion, and a 1970s Vax 11/44.

Usagi Electric

Welcome to Usagi Electric! On this channel, we dive into old school technology, focusing heavily on vacuum tubes. My primary goal is to build computing circuits based off the legendary machines of yesteryear, only with a slight modern twist. All the tubes will be operating with very low...

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[HiBaller]

I used to own a Vax 11/34 with the CAPS-11 operating system. Sold it about 1990 or so.

Bill

 

[JCitron]

I used to own a Vax 11/34 with the CAPS-11 operating system. Sold it about 1990 or so.

Bill

That's really awesome. You should've kept it and sold it now, they're worth quite a bit today among the old computer enthusiasts.

The voltage requirements of these old computers are really scary though. The 11/44 has a +5V 120A power bus with equally high currents for the +/- 12V and the +40V line. The power supply has crazy voltages too.

 

[KotangaGirl]

I am so going to tell my daughter about this Youtube channel. Thanks John.

 

[pcas1986]

My first computer a Texas Instruments TI 99/4 that didn't make the list on that site. Maybe too new at 1976. My first work computer was a pair of Univac 418-III computers that together were the size of a small family car. The disk drives were 20 metres away in a sealed room. I wrote programs for it with hollerith punch cards.

Now I feel rather old. That was almost 50 years ago!

 

[HiBaller]

My first computer a Texas Instruments TI 99/4 that didn't make the list on that site. Maybe too new at 1976. My first work computer was a pair of Univac 418-III computers that together were the size of a small family car. The disk drives were 20 metres away in a sealed room. I wrote programs for it with hollerith punch cards.

Now I feel rather old. That was almost 50 years ago!

At my second duty station in the navy, I had a brand new Data General Nova II on my sideboard. My task was to program it for several things having to do with the spherical geometry involved in direction finding. Learned machine language from scratch. Until we had better terminals, I had to use the front panel switches to load a program.

Bill

 

[HiBaller]

That's really awesome. You should've kept it and sold it now, they're worth quite a bit today among the old computer enthusiasts.

The voltage requirements of these old computers are really scary though. The 11/44 has a +5V 120A power bus with equally high currents for the +/- 12V and the +40V line. The power supply has crazy voltages too.

Yep. The power demand was rather high. When I powered it on, I had a 50/50 chance the 50 amp breaker would pop. I learned to power it up in stages.

About that time, Heathkit came out with a VAX-11-based home computer kit. I bought one of them as well as a Heathkit H-8 8080A computer.

Bill

 

[JCitron]

Yep. The power demand was rather high. When I powered it on, I had a 50/50 chance the 50 amp breaker would pop. I learned to power it up in stages.

About that time, Heathkit came out with a VAX-11-based home computer kit. I bought one of them as well as a Heathkit H-8 8080A computer.

Bill

I wondered about circuit breakers popping. I was scared about getting zapped pretty badly back when I worked around power supplies and CRTs where I got knocked on my backside one day by a nasty discharge from a video terminal that wasn't grounded properly.

A Heathkit Vax-11 home computer. Wow, that's amazing. Sadly, they disappeared just as I became serious about electronics.