<The floppy disks are 8" RX01 compatible drives. The interesting thing is
<that this device can format the disks, not by some special format command
<procedure... it formats a sector when it writes it...
It happens to use a 1773 floppy controller that can format, there is also
local ram and an 8085 micro to make the disk appear smarter.
<The on-board ROMs know about RT-11 Queue elements, so the RT driver
<simply calls the ROM to handle the I/O, and the ROM returns if there
<was an error, or when the request is complete.
Between the Disk system with it's 8085 and the DL compatable IO that also
has its own 8085 Plus either 3 ot 6 2651 usarts) it's easy to see how the
system is smarter in some places. for a small system that makes it unique
for it's time.
The same basic bard set was used in the PDT-11/110(MOP loaded) and 11/130
(TU58 tape) the main difference was the use of TU58 (unique with a parallel
interface) and some minor rom level code to boot it.
<I don't know of anything else which ever ran on it... (I would be
<interested to know if there ever was).
I head someone had COS running in it. In theory is a vanilla 11/2 with
28KW of ram and a series of DL ports and a mass storage device that is
sorta RX01(two 256k floppies RX01 format). Unless you used DDCMP to another
system storage would be the limiting aspect.
NOTE: expansion is not possible, there is no externally acccessable bus
or expansion port.
I have the PDT11/130 version and several boards for PDt150/130 as spares.
Allison
Received on Sun May 09 1999 - 11:05:41 BST