24 May
2020
24 May
'20
5:56 a.m.
-----Original Message-----
From: cctalk <cctalk-bounces at classiccmp.org> On Behalf Of Tony Duell via
cctalk
Sent: 24 May 2020 10:28
To: rob at jarratt.me.uk
Cc: General Discussion: On-Topic and Off-Topic Posts
<cctalk at classiccmp.org>
Subject: Re: Alternative Monitor for VAXmate
On Sun, May 24, 2020 at 9:23 AM Rob Jarratt <robert.jarratt at ntlworld.com>
wrote:
The only think I found was a reference to the IBM 3179G.
Tony, are you aware of any device I could buy or circuit I could build to get a
decent image out of it? It doesn't have to be perfect, but at least usable.
Unfortunately not. That 26kHz horizontal frequency is the problem...
It's not close to any of the PC standards (MDA, CGA, EGA, VGA). Nor
television (I even thought of the French System E 819 line, but that's around
20kHz). And those are the common standards.
I think you options are either to try to modify VGA
monitor to scan a little
slower, to design some kind of standards converter (which is a lot of work!)
If the output is digital, would it be possible to build an FPGA scan converter to go to
VGA?
Is the output always 26Khz?
or to make a new flyback transformer. The last would
be what I would look
into, if only because it keeps the machine original
You would probably have to vacuum-impregnate the windings to prevent
flashover, but the model internal combustion engine crowd make their own
ignition coils and manage to do things like that.
Sounds harder to me than an FPGA scan converter...
-tony
Dave