Homebrew Drum Computer

[Jules Richardson]

Allison wrote:
> Most of the old Drum machines spun at 1200, 1800, 3125 or maybe a screamigly 
> fast 3600.  Though 1800 is the more common.
> 
> Also most used "fast tracks"  that had more than one head per track
> radially so that a partial rotataion was needed.

Indeed - the museum's pair of HP 1016C drums are 512 tracks and something like 
32 segments (I'm going by memory on the latter). My brain's telling me that 
drum speed was 4800RPM.

Head-load is done by a big solenoid on the top of the drum - when powered it 
pulls on a large arm which, through a ring assembly, pivots all the columns of 
heads in toward the drum surface.

Quite an impressive bit of engineering...

cheers

Jules