Alternative Monitor for VAXmate

[Rob Jarratt]

> -----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
> 
> 
> 
> > -----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:
> >
> > >
> > > 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.
> >
> 
> The only think I found was a reference to the IBM 3179G.
> 
> > 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?


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.

> 
> > 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