DEC hardware questions

From: Eric Smith <>
Date: Wed Apr 5 15:03:12 2000

Ethan Dicks <> wrote:
> 16-bit machines (PDP-11) use 12 sector cartridges. 12-bit machines (PDP-8)
> use 16-sector cartridges. The difference is in how many saw cuts are made
> in the aluminum rim on the bottom. While it is *theoretically* possible
> to plug the wrong cuts and make new ones in the correct place, I am not
> aware of anyone attempting this, let alone succeeding.

Better yet, how about a hardware hack that drops the hard sector pulses
entirely, and uses a PLL to derive the desired number of sector pulses
from the index pulse?

Should be possible to implement with a software digital PLL in a Scenix
microcontroller, or maybe even a PIC.

Then you could mount a switch on the front panel to select 12 or 16 sector
operation, regardless of the pack.
Received on Wed Apr 05 2000 - 15:03:12 BST

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