24 May
2020
24 May
'20
3:46 a.m.
-----Original Message-----
From: cctalk <cctalk-bounces at classiccmp.org> On Behalf Of Dave Wade via
cctalk
Sent: 24 May 2020 10:57
To: 'Tony Duell' <ard.p850ug1 at gmail.com>; 'General Discussion:
On-Topic and
Off-Topic Posts' <cctalk at classiccmp.org>
Subject: RE: Alternative Monitor for VAXmate
The horizontal sync is 26KHz, yes. Maybe an FPGA could do it.... I would definitely prefer
a replacement flyback, but really no idea how to go about building one.
-----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