RT-11 and TCP/IP

From: Jerome Fine <jhfine_at_idirect.com>
Date: Tue Feb 2 11:18:15 1999

>Zane H. Healy wrote:

> I'm embarassed to say I've never learned to use Kermit, and I STILL don't
> have the blasted system talking to the RX-50!

Jerome Fine replies:

Any RQDX1,2,3 controller can support the RX50 dual drive
from DEC. NOTE that the RQDX1 MUST be the last board
in the backplane since it has no bus grant continuation. ONLY
the RQDX3 supports the RX33. In a BA23, the use of just
the RX50 is via the right hand header in the I/O distribution
panel which is just in back of the space for drives. A straight
through cable without any twists is the correct connection.
Likewise for the cable from the RQDX3 to the I/O distribution
panel via the little opening just below for I/O distribution
panel.

> > the PC and the PDP-11. The PDP-11 is running V5.4G
> > of RT-11 which has been patched to be Y2K compliant
> > and the MSCP device driver has even been fixed so that
> > non-zero partitions on the RD53 can also be booted after
> > the initial hardware boot.
> I've a different solution, a WQESD controller with a 150Mb ESDI drive, that
> allows me to boot non-zero partitions, since to the OS, the appear to be
> zero partitions. Cheaper than SCSI, and no *&^% $%## RD53's!

Yes!!! I AGREE!! RD53s drives don't live all that long.
and SCSI is still very expensive since the Qbus host adapters
have not become inexpensive, as has most other PDP-11
hardware. Why don't you just switch to an emulator on your
PC? It is also much faster than the PDP-11!!!! UNLESS
the real fun is running on real PDP-11 hardware and the
software is not the issue. With me, the software is far
more important than the hardware.

I have seen an 11/73 systems with a Sigma RQD11-EC, a quad ESDI
MSCP compatible Qbus controller which allows up to 4 ESDI drives
of any size. The system I saw had 3 * 600 Mbyte Hitachi DK515-78
drives. I was told that the drives set as units 1 and 2 were only for
backup and all 20 partitions on each drive were identical after the
backups had been done. Of the 60 partitions in total, all could be
active simultaneously and all were bootable. The Sigma controller
does allow fixed hard drives to be split into segments or partitions
of various sizes each with its own UNIT number which can then
be booted from a hardware level. But I understand that the drives
were not segmented in any way as the firmware on the Sigma
controller was told that the drives were removable. In fact, a
demonstration was made - VERY CAREFULLY - and one
of the drives was powered off, uncabled, and a different physical
drive substituted while everything else was still running. The
new drive cam back on line and was available without a hitch.

You can do the same thing with an RD53, but you MUST usually
UNLOAD and LOAD the device driver the activate an RD5x drive
after it is powered down. If the system device is also the same
device driver, then a software BOOT is required. If you are running
from a different device driver, then the UNLOAD and LOAD
with re-initialize the RQDXn and bring the RD5x back on-line.

Sincerely yours,

Jerome Fine
RT-11/TSX-PLUS User/Addict
Received on Tue Feb 02 1999 - 11:18:15 GMT