How to avoid typing in programs from books
A few years ago I had a very old DEC PDP-11/73 minicomputer dating from the early to mid 80s. It could boot off its 32MB hard disk, or from 8" floppies or RL02 disks - 10MB disk packs about the size of dustbin lids. You turn the power on, and it would display a big scrolly message indicating that it belonged to Aberdeen College of Agriculture, then a little "boot:" prompt where you typed the letter for the drive you wanted to boot off. After ten seconds or so, it would boot to DU0: which was the first hard disk partition. Great. Until the fateful day when one of the boot ROMs went phut. Arses.

Now actually booting the machine wasn't too hard - you could drop it into an octal debugger where you could program it by typing in big strings of numbers, rather like typing in programs from magazines in the early days of home computers. This got old pretty fast, though, because you needed to type in a couple of dozen four digit numbers *every time*.

"Hang on a sec", I thought, "this terminal I'm using has programmable function keys that can store sequences of keystrokes. Wonder how big a sequence it can store?"

Big enough as it turns out. So when my PDP11 was donated to a museum, along with all the manuals went a piece of paper describing which combinations of CTRL, SHIFT and function keys to press to send the magic words to boot it up.

I may have just out-geeked the whole Internet.
(gordonjcp, Sat 22 Aug 2009, 8:56, 7 replies)

Yes, Yes you did.
Bill Gates just called you a geek on his Twitter.
(Galahad is out of his gourd on yellow bentines, Sat 22 Aug 2009, 9:06, closed)

Couldn't you burn a new boot ROM?

( idonthaveafunnynickname Drink-Aware? Sure. I'm aware I want another drink., Sat 22 Aug 2009, 15:44, closed)

I could...
... if I had the image to blow onto it. The annoying thing is that I contacted the company that made the boot ROM board (still in business) only to get an email from the guy that designed the board and wrote the software telling me he'd put all his old PDP11 stuff in the skip nine months earlier when he'd moved offices.
(gordonjcp, Sat 22 Aug 2009, 21:09, closed)

Isn't the term
'blow' with an EPROM blower?
( sandettie light vessel automatic New Twitter - @bollocksreally, Sun 23 Aug 2009, 2:20, closed)

;)
Wouldn't octal be strings of three letters?
(Lukekull Fuck, Sun 23 Aug 2009, 0:27, closed)

Nope
Octal is made up of digits from 0-7 (corresponding to three bits). I actually got that a bit wrong - it was five octal digits to give an 18-bit value, for which the two highest bits were always 0 for 16-bit words. Confused? You will be. The earlier PDP-8 used 12-bit words, which had four octal digits, so the values ran from 0000 to 7777.
(gordonjcp, Sun 23 Aug 2009, 10:19, closed)

WTF?
My brain has just melted out of my ears after reading this.

Definetly one for the 'outgeeking of teh internets' category.
(danniekavanagh did nothing constructive on, Sun 23 Aug 2009, 19:32, closed)