19 Jun
2005
19 Jun
'05
5:18 p.m.
Subject: booting and 11/44 via tu58 sim?
From: Brad Parker <brad at heeltoe.com>
Date: Sun, 19 Jun 2005 17:05:14 -0400
To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at
classiccmp.org>
Hi,
On a whim (hey, it's father's day :-) I decided to try and boot my
dormant 11/44 from the TU58 using the tu58 simulator.
Has anyone done this?
Functionally it should. last time I did it I used a real tu58
in a lab back at DEC on a reabygosh(tm) 11/44. had to run the
DL port slow.
I'm being totally lazy and didn't look at the
M7090 schematics (yet) and
assumed the TU58 20pin header is the same as the console 20pin header.
I also assumed it's RS-232 and not TTL. Further, I assumed it was
running at 38400 baud.
Both do RS423 (6wire version of RS232, sorta), you will need to
verify hookup but it works.
Naturally it didn't work right off the bat... :-)
I know my serial port and tu58 simulator are working since they boot my
11/730 just fine.
I'll look at the schematics but I thought I'd ask for any sage advice.
(luckily my spare UBI board had a DD boot rom on it)
-brad
Run slower, the 11/44 the DL port used typically for TU58 is down the
interrupt priority and it can loose data if too fast (overrun).
I'd start at 4800 (known good) and then try 9600 or faster.
Allison