2 Nov
2009
2 Nov
'09
8:33 a.m.
If that doesn't work, another thing that occurs to me is that you might want to take a
scope to the serial line. Typically, RS232 requires a voltage that's not used by much
else, and if that rail is noisy (from a filter capacitor that's not capaciting, for
instance), that might give you this behavior, too, without mucking up anything else. --
Ian
________________________________________
From: cctalk-bounces at classiccmp.org [cctalk-bounces at classiccmp.org] On Behalf Of JP
Hindin [jplist2008 at kiwigeek.com]
Sent: Monday, November 02, 2009 8:27 AM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: RE: Talking to a VAX4000/300
On Mon, 2 Nov 2009, Ian King wrote:
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
I have it set to 9600 on both sides. I know I used this term to talk to my
-other- VAX4000 at 9600, so it really shouldn't be an issue.
I'll try dialling down the speeds.
It occurred to me that I should see if it still works on the -other- VAX,
which I know I used to work with on this term. I thought I'd pop the good
PSU out of the new VAX, stick it in the old, and fire it up with the same
settings (9600 8N1) and see if it's clear or gibberish, just to exclude
some kind of fault in the new VAX. That might be why they dumped it ;)
Thank you, Ian. If the old VAX gives the same problem, I'll click the
speed back to 1200bps.
- JP
________________________________________
From: cctalk-bounces at classiccmp.org [cctalk-bounces at classiccmp.org] On Behalf Of JP
Hindin [jplist2008 at kiwigeek.com]
Sent: Monday, November 02, 2009 7:39 AM
To: cctalk at classiccmp.org
Subject: Talking to a VAX4000/300
Greetings all;
I picked up a VAX4000 last week and have been trying to get talking with
it. I found a general VAX4000 series guide which says the terminal
settings should be 8N1 and I've got the speed right between the dial on
the front of the VAX module and the VT240 I'm using.
I get partial data, with ?s scattered all over the place. Frequently it
loses carriage returns and things get stuck scrolling off the side of the
screen.
What am I missing here? Is it not 8N1? I've tried flipping it around to
7N1, 7E1, etc, but usually that just results in absolute gibberish, the
8N1 provides the best signal-to-noise ratio.
I'd appreciate any thoughts given.
Elsewise, I'm pretty pumped. I have another 4000/300, but it has a bad
PSU. I figured I'd put the two together to get the nicest working machine,
store the spare PCBs and dump the chassis (anyone want an empty
4000/300?). The unit is complaining about some memory errors (came with
four memory boards), but with all the crap coming up on the screen, I'm
not entirely positive what it's complaining about since I can only read a
partial output...
Thanks again;
- JP