3 Nov
2009
3 Nov
'09
1:27 p.m.
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-
bounces at classiccmp.org] On Behalf Of JP Hindin
Sent: Tuesday, November 03, 2009 6:39 AM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Talking to a VAX4000/300; Also RAM
On Mon, 2 Nov 2009, Dave McGuire wrote:
Glad to help, even if it wasn't needed. :-) So what boards are those? The 4000/300
Technical Manual calls out two different memory boards, one 32MB, the other 64MB, and
there are four memory slots. I'd *love* to beef up my 4000 with more than 128MB. --
Ian
On Nov 2, 2009, at 11:14 AM, Ian King wrote:
Much to my embarrassment I discovered the issue was _not_ the speed, or
noisy lines, or corroded batteries or RS232/423 problems. I was a total
nitwit and neglected to notice I had it set to 8E1 instead of 8N1.
Remarkably with this small change, I can now speak to it clearly at
9600bps.
<Hand to forehead repeatedly and with force>
Should I be amazed or not that this 4000/300 has a half-gig of RAM? My
first 4000/300 came with a single 32M board, this one comes with 4x
128M
boards (one of which is flaky). The documentation I can find says the
4000/300 maxes out at 128M, which... clearly isn't so:
http://www.kiwigeek.com/misc/VAX4000_Mem_Count.JPG
Where would the sages suggest I begin in tracking down a fault in one
of
the four boards:
http://www.kiwigeek.com/misc/VAX4000_Mem_Errors.JPG
My thanks to everyone who made very good, but due to my incompetance,
unused suggestions.
What line speed are you running at? I have a
4000/300, too (great
machine - congratulations!), and I haven't had that problem with
either a VT420 or a terminal emulator. I'm using 8N1, so I'm sure
you're right there. But I wonder if the VT240 is just not keeping
up with the VAX, i.e. insufficient speed and buffer space. I've
seen that before, where a terminal *can* talk 9600 but can't do it
for very long. Hm, I think I have a VT240, maybe I should give it
a try.... -- Ian
VT240s, while wonderful in other ways, are very slow terminals.
It wouldn't surprise me if he were simply getting overruns. 
