Build Your Computer using Logic & Memory, before the advent of microprocessor

[ygg-it]

I'm at the end of Apollo181 project and so I have finally released the video:

Build Your Computer using Logic & Memory, before the advent of microprocessor

which is about a homemade didactic 4-bit CPU made exclusively of TTL logics and bipolar memories, in particular the 74181 Arithmetic and Logic Unit.

I hope you will enjoy it.

Please leave here your comments if you wish. Thanks.

GG

 

[Lawrence Woodman]

That was a great video, really well put together. I particularly liked the way that you reviewed the historical background and use of the 74181.

For anyone interested the APOLLO181 site is also worth looking at for further background detail, schematics, etc.

 

[Oscar]

Please leave here your comments if you wish. Thanks.
GG

Comments? Wow! Not only did your creation explore a really interesting (and unexplored) time in computer development, not only did you provide a lot of material to study it - you also provided me with two evenings of fun! Thank you, sir!

Oscar.

 

[Chuck(G)]

Wasn't there a similar project published in Kilobaud or Byte during the late 70s/early 80s?

The gap between the microprocess and IC deployment is actually quite small in terms of years. In the very late 1960s, there were a few systems still being produced with discrete (transistors, diodes, resistors, etc.) logic. Considering that the first microprocessors came out in 1971, that's a pretty narrow gap for an all-SSI processor. And the early ICs weren't TTL at all--CML, DCTL, DTL and even RTL preceded TTL ICs.

 

[g4ugm]

In the UK there was a "weenie bitter" there are some examples in the ACC Mags here:-

http://www.smrcc.org.uk/members/g4ugm/acc.htm

although I seem to have lost some.. there are more on the site than in the index....

 

[MikeS]

And another one; 3000 transistors:

http://www.6502.org/users/dieter/mt15/mt15.htm

Check out his other projects:

http://www.6502.org/users/dieter/timeline/timeline.htm

 

[Chuck(G)]

And another one; 3000 transistors:

http://www.6502.org/users/dieter/mt15/mt15.htm

That's pretty amazing considering that the PB250 had fewer than 400 transistors, 22 bit words, 59 instructions and handled Flexowriter and Mag tape I/O. Bit-serial architecture and magnetostrictive delay line for just about everything (even the registers were magnetostrictive line) really cuts the active component count. This could well be the first commercial minicomputer, circa 1959.

 

[ralphcorrales]

In the UK there was a "weenie bitter" there are some examples in the ACC Mags here:-

http://www.smrcc.org.uk/members/g4ugm/acc.htm

although I seem to have lost some.. there are more on the site than in the index....essay service

Some information on the site can be closed for indexing I think...

 

[g4ugm]

Some information on the site can be closed for indexing I think...

It was the index on the contents page that was missing links!. It was a problem when I was using FrontPage to build the site. I switched to Drupal some time ago and the list should now be complete.