Talking to a VAX4000/300; Also RAM

[Ian King]

> -----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:
> > On Nov 2, 2009, at 11:14 AM, 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
> >
> >    VT240s, while wonderful in other ways, are very slow terminals.
> > It wouldn't surprise me if he were simply getting overruns.
> 
> 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.
> 

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