(very OT) Ideal partition schemes (history of partitioning)

[Doug Hardie]

-- Doug

> On 29 August 2020, at 12:27, Steve O'Hara-Smith <steve at sohara.org> wrote:
> 
> 	I'm from 59, I used punched cards and paper tape on an IBM-1130 for
> my start in computing, then went on to teletypes and a DG Eclipse before
> encountering one of the first TRS-80s in the UK (I said "Nice keyboard
> where's the computer"). Then I went to college and met an IBM-370. I didn't
> meet floppies until after college when I worked on the Torch - if anyone
> remembers it CPN was my idea and Dave Oliver made it good.
> 

I started wiring boards to program an analog computer.  Shortly after that, the college computer center had a stand along printer, IBM 407 accounting machine.  You programmed it using a very large plug board and lots of wires.  Two of us figured out how to make it solve 10 simultaneous linear equations and actually got it to work.  We did have some help from our IBM maintenance man who showd us how to avoid the clutch burning out.  Once he verified that it worked, he took lots of pictures of the board from different angles so you could see all the wires and took it back to IBM.  

Later we used paper tape (5 level) on a PDP-11/45 which only had an 8 level reader and punch.  We had to send tape to the communications center and receive it from them.  The tape came folded in boxes.  I had to build some aluminum blocks with fairly complex angles to securely hold 5 level tape in the 8 level reader and punch.  However, if you took the used tape, which was normally thrown away and cut it at each of the folds and then taped them into circles interconnected, you had a wonderful chain that was really neat on a Christmas tree.  We did that for several years.  Somewhere I have pictures of one of the trees.

I also got sent to a micro computer programming class using the KIM-1.  A complete waste of my time, but interesting.  The KIM had a pizoelectric crystal buzzer on it.  In the class, someone asked the instructor if it could be programmed to play music.  The instructor was adamant it would only produce one note.  However, as a ham, I had used crystals for years and you can pull the frequency with capacitors or inductors.  I figured that could be emulated at audio frequencies.  I stayed up the entire night programming it to pulse the beeper with a single clock pulse at the frequency I wanted to produce.  It worked.  By the time the class started, I could make 3 part harmony and went in a bit early and had it playing some simple Christmas carols when the other arrived.  The instructor was not pleased.

-- Doug