Exploring early GUIs

Eric Smith spacewar at gmail.com
Mon Sep 21 15:11:23 CDT 2020

On Sun, Sep 20, 2020 at 3:24 PM Mike Begley via cctalk <
cctalk at classiccmp.org> wrote:

> There's also the windowing system used on the AT&T 3B1 (AKA Unix PC, AK
> PC7300), which I think was called MGR.  It may have also been ported to
> other systems as well.  When I had one of these machines it was adequate,
> although terribly slow on a 512K system.

MGR was not the Unix PC's native GUI environment; I'm not sure what that
was named. MGR was an open source environment that could be installed on
the Unix PC. For best performance, it was necessary to replace a PAL chip
on the motherboard ("VIDPAL") to allow user-space access to the frame
buffer. The native GUI environment did not require or benefit from that.

The linked photos are of the native GUI environment.

Since the Unix PC was developed by Convergent, and the SVR2 it runs is
derived from Convergent CTIX, I suspect that the native GUI environment was
from Convergent as well. It might be derived from Convergent WGS/Desktop,
but I've never seen that.

More information about the cctech mailing list