PDP-8: anyone tried NVRAM simulation of hard drives?

From: Lawrence LeMay <lemay_at_cs.umn.edu>
Date: Mon Jan 27 19:02:31 2003

My thoughts on the subject have always been that if a hard drive replacement
is designed in such a manner that it works on a REAL PDP 8, omnibus or posibus,
I'll be first in line to order some circuit boards.

-Lawrence LeMay


> Has anyone had interfaced nonvolatile RAM to a PDP-8 to simulate an original
> hard drive? The DF32 fully expanded with four disks was only 256k x 12...
> Dallas Semi makes battery-backed NVRAM in a variety of sizes. Two DS1258
> (each 128k x 16) would make for a very simple interface that would fit on a
> single card (or at most a double card). Packing the 12-bit words would
> complicate the interface a little but lower the cost of the NVRAMs.
>
> Using an old 3.5 or 5.25 inch hard drive would be very cheap per meg but
> would also require development of a controller (like the 8051 mentioned
> recently as an interface to an HP computer). I don't think there were any
> original drives greater than 1 Mword available, so larger ones would require
> nonstandard code to support them anyway.
>
> Any thoughts?
> -Charles
Received on Mon Jan 27 2003 - 19:02:31 GMT