LGP-21 Hardware Training Manual

[Tom Jennings]

On Thu, 2004-09-23 at 06:26, John Foust wrote:

re: lossy images

> If your image-converting program is smart, it will let you
> use a 0..255 grey palette for a GIF.  If it's true line-art with
> no greys, it'll have better compression with almost any palette
> that has a black and a white in it.

I'm using the PBM tools, so I just made all the tiffs into pngs, which
work fine, and they're uploading now.


> And I'm extremely jealous of that computer.  :-)  It gives me
> flashbacks to glorious old '50s junk I'd find in dumpsters or
> auctions or rummage sales and disassemble.

I feel lucky to have it, I can assure you. It's actually the perfect
machine, though architecturally it's a bit bizarre and limited, it's
solid state yet first-generation architecture still. The LGP-30 is far
more complex, electrically and mechanically, plus it's 800 lbs! Other
than the memory and Friden, the LGP-21 is just a bunch of transistors.
It eats 300 watts from the local nuclear or coal station.

(It really is a first generation arch, like the '30; arithmetic only
order set, non-character-oriented, no index register, drum, serial, one
accumulator, though it has hardware subroutine support (barely) with the
R instruction.)