5 Apr
2005
5 Apr
'05
4:21 p.m.
Subject: Re: rx01 w/o controller board
From: Pete Turnbull <pete at dunnington.u-net.com>
Your host adapter is little more than a parallel
interface; it talks
over a 40-way ribbon cable (but less than half the pins are used) to
one of the boards on the RX02 unit which has a state machine to execute
various commands, and that board in turn connects via another ribbon
cable to the lower board, which has the amplifiers and so forth on it.
The head cables plug into this lower board.
The state machine is a simple but programable non-von cpu that can do
the needed tasks to execute complex command to seek, read or write
a sector. The RX02 is a 2901based bitslice that does more as it
has to do the needed tricks for DD format.
An aside for CPU hackers, the core cpu of the RX01 processor is remarably
simple and can execute 5 distinct microinstructions with a few variations.
A varient of the same logical core was used to build the LA34 printer and
LA120 and a similar design is in the LP26 DAFU. It was a fun project
years ago building one and tweeking it to do a simple 8bit cpu.
AFAIK the drive mechanisms for an RX01 and RX02 are the
same; only the
boards differ.
Correct. The drive and power suppies are interchangable, The two
boards are different for the 01/02 though mechanically interchangable.
Allison