Remembering 36-bit DECs

rjinbanff writes: "Very interesting read that details a number of historical events in Computing history (Kermit, EMACS, etc). Self-described as: "A nontechnical reminiscence written in 1988 (on the occasion of unplugging Columbia University's last DECSYSTEM-20) for a Digital Press book that was to commemorate DEC's 36-bit machines with a series of articles, but was never published." Minor edits, notes, glossary, links, and HTML formatting added in January, 2001."

byte? 8 bits?

You're using a very recent notion of "byte" . . .

It hasn't always meant 8 bits. And there was nothing special about 8 bits--certainly not the size of a character.

With an ascii character set, the dec's put 7 characters/word, with one left over (which I think was used to indicate the last character in certain circumstances.

The data, though, was 36 bits, not 32+parity. Besides, if you want to do that, I think the correct number is 38, not 36, to allow 1 bit correction and 2 bit detection.

OK, OK. that's not the real reason for 36 bits. Remember how cars used to have real spare tires instead of the toy spare? Computers were like that, too. If you burned out bit 7 of the processor, you had some spares to use . . .

(really not as facetious as it sounds. Core memory used to come with spare rows & columns . . .)

You're not fooling me!

"A nontechnical reminiscence ..."

Oh, ok I only counted 87 definitions in the glossary. I guess it has to be 100 before it's "technical".

"The most important contribution of the DEC-20 to networking was its support for the ARPANET protocols, first NCP and later TCP/IP. For many years, DEC was the only major computer vendor to support these protocols, which were mostly developed on DEC 36-bit machines under TENEX, TOPS-10, and TOPS-20 (and later on VAXes for Berkeley UNIX). "
Ok so us geeks understand this, but come on!

I think I'll print this out for my Grandma to read!

What a great read

That was a great read. While I didn't get to touch a mini or mainframe system until I went to RPI in 1988 (PCs were just starting to become widespread), I remember many days of going to work with my Mom who was a mainframe programmer all her life from the late 1960's on. Talk about awe inspiring.

I thought the epilogue hit it right on: "Meanwhile, many of us who lived through that era retain our old habits, still using text-based applications such as EMACS and MM (or its successor, Pine) rather than their fashionable GUI replacements, but on UNIX platforms (Solaris, Linux, etc) instead of PDP-10s. Each time a new PC virus plunges the entire organization into chaos and panic, we barely notice. There is something to be said for the old ways."

So true.

Another thing. THough today we have massive amounts of software available, its somehow less satisfying it seems. Sure, you can deploy a major system, joining lots of software packages together and perhaps even modifying them some to do the job, but how exciting it must have been to be part of the group blazing the trail of timesharing user access, email, TCP/IP via Arpanet, and more. How satisfying it must have been.

Finally, I still shake my head is disbelief how fast things have changed. Back in 88, PCs were available, but not widespread, mostly due to lack of network access. I remember thinking how cool it was to have a BITNET address and being able to communicate with folks around the world. TCP/IP was made available to us around 1990. But to think that was only 10 years ago! In 88 I had a 4 or 8MHz XT (can't recall) and graduated with a 33MHz 386 just as 486s were hitting the market. Now, 8 years later I'm reading Slashdot on this web thing using a Pentium III laptop running @ 700MHz, connected to the internet via wireless networking to my DSL internet connection. 8 years ago we were psyched to have 9600 baud serial modems in each dorm room connected to the campus network.

Mind boggling.

36bit architecture

Unisys still use a 36 bit architecture in their 2200 mainframe class machines.... caused no end of grief to the new graduates at the last place I worked, on a UK banking system *grin*

Interestingly enough, these machines still power most of the airline reservation and core banking systems in a significant part of the world.

If someone came up with a 68bit (for instance) architecture nowadays we'd all be on /. accusing them of smoking crack!