Ancient disk controllers

From: Richard Erlacher <edick_at_idcomm.com>
Date: Sun Apr 18 23:49:14 1999

It's like I wrote a few days ago. There was a bit of confusion about what
was what. Several different forces at WD were shuffling for turf,
apparently, and the prize, in this case, was the 1000 designation vs the
1001. They had data sheets about a 1000-08 controller but that never made
the price list. I have several of the OLD (meaning with the 8X300 + WD1100
chipset) tuned for handling ST506 drives, but none for 8", though I tried to
order them through distribution. Western send me several versions of the
small board with the 1010, 1014, and 1015 chips as samples, but I couldn't
get any of their offering for the 8" drives. I didn't need them, so it
didn't really matter.

I don't know how far back you remember, but the 8T31 is what they called an
interface vector, in the 8X300 doc's, and what it really is, essentially, is
a 74373 with built-in decode logic. It can work in either direction so you
can use it in both input and output applications. The part is described in
the OSBORNE series on microprocessors, in case anyone is interested.

The 8X300 is a true RISC. it has 8 instructions and, on the original
version, each one took 300 ns. on the version which was current in 1980, it
was customarily used with an 8MHz clock which meant each instruction took
250 ns, and in 1981 they trimmed it down to 200 ns with their 8X305. These
processors showed up in lots of tape controllers and the like, perhaps an
occasional SMD, and at least one LAN application, though I don't know what
the protocol was.
Received on Sun Apr 18 1999 - 23:49:14 BST