On 07/28/2017 12:21 PM, Rob Jarratt via cctalk wrote:
So the vertical range of the signal is about 0-5V (about 2V per division) ,
I can't remember the timebase though, but I think it was about 0.1us per
division. I will do it again (later) with more info. The signal was found on
a data pin of the
> -Original Message-
> From: Phil Blundell [mailto:p...@pbcl.net]
> Sent: 28 July 2017 18:27
> To: r...@jarratt.me.uk; Rob Jarratt ; General
> Discussion: On-Topic and Off-Topic Posts
> Subject: Re: DECstation 220 Impasse Reached
>
> On Fri, 2017-07-28 at 18:0
On Fri, 2017-07-28 at 18:04 +0100, Rob Jarratt via cctalk wrote:
> Anyone have any thoughts on whether those data signals look right?
It doesn't look obviously wrong. If the vertical scale is 2V per box
then the amplitude is probably about right for 74LS logic. I think you
said this was on a sha
Message-
> From: Paul Koning [mailto:paulkon...@comcast.net]
> Sent: 28 July 2017 18:17
> To: r...@jarratt.me.uk; Robert Jarratt ;
General
> Discussion: On-Topic and Off-Topic Posts
> Subject: Re: DECstation 220 Impasse Reached
>
>
> > On Jul 28, 2017, at 1:04
> On Jul 28, 2017, at 1:04 PM, Rob Jarratt via cctalk
> wrote:
>
> Anyone have any thoughts on whether those data signals look right?
It's hard to guess at signals when the horizontal and vertical scales are not
stated, nor where in the circuit the signal was found.
paul
Anyone have any thoughts on whether those data signals look right?
Thanks
Rob
From: Rob Jarratt [mailto:robert.jarr...@ntlworld.com]
Sent: 27 July 2017 21:18
To: General Discussion: On-Topic and Off-Topic Posts (cctalk@classiccmp.org)
Subject: DECstation 220 Impasse Reached
Hello
Hello Everyone,
As I have mentioned before I have made some progress on a DECstation 220,
but I have reached an impasse. I get some signals on the data bus which I am
not sure about. They look odd, but they could be normal, I just don't know.
I took a picture of the scope trace, which is here:
