RX50 / RX33 Questions related to PDP-11's

From: Allison J Parent <allisonp_at_world.std.com>
Date: Wed Oct 14 05:36:58 1998

< admit) with a RX50 attached, it will access the floppy drives, this is b
< evidenced by my using a cleaning floppy in the drive (made it easy to he
< the drive being accessed).

RX50s are rather loud. ;)

< When I try using a pair of Teac floppies I've converted to RX33's using
< information I found on Sunsite I'm not really sure it tries to access th
< How do you cable RX33's? I set them to Drive 0 and 1, as the docs said
< and then used a Y-splitter for the power with a standard PC floppy cabl
< (do I need one without the twist?). Can you use RX50 floppies to boot
< system with RX33 drives?

Ok, TEAC FD55GFV (RX33) or TEAC FD55F (RX50). The cable must not have
twist and drive select is 1 for the first, I only use one on the system
as I have 3 RD52s. IF the drive speed select and density select jumpers
are set right it (using RQDX3) will sense what the media is and operate
correctly using the DU boot. None or all of this will be true for the
WQESD controller, I don't know it.

< Will RT-11 boot off of a floppy drive at CSR 17760334? I've tried with
< both the Boot disk from my RX50 distribution set, and a RX50 boot disk t
< I made using PUTR. I've a sinking feeling that having two disk controll
< is confusing RT-11.

17772150 it the default first device and the default bootable. If there
is two the second will be at 17760334. For RQDXs the LUN jumper must
corospond to how many units.

I believe PDP-11 ROM BOOT expects to boot from the default first (*2150)
unless the DU.sys driver has been changed for the second address. RT-11
itself will boot/run on anything you have a driver for. Megan would
know for sure. I've never found it necessary to have two MSCP disk
controllers in a PDP-11 (I was using them in the vax instead!).
 
< Is it possible to create a Bootable TK50 with RT-11 that can be used to
< the install?

That's oblique. It's possible to make a bootable RX50(or RX33) that is
complete enough to be a system! To install from that is trivial as it's
really INITing the target drive (assuming its LL formated) and copying
everything to it then doing a copy/boot operation. Not much majik unless
the version of RT has been really tweeked.

Allison
Received on Wed Oct 14 1998 - 05:36:58 BST