>While I realize that it would not have been possible to make
>their graphics part of the standard OS for a PDP-11, I
>was led to believe that the PR0 350/380 had access to
>their bit mapped screen displays. While doing such
>manipulations was likely discouraged, is that a true
>statement of the situation and in a few lines, how was
>it done? I may have a working PRO 350/380 and
>it would be interesting.
Yes, it is true... in fact, when the PRO was not yet real hardware,
the development group had special Qbus options for their Qbus -11
systems which were very similar to what was eventually made into
the bitmap graphics of the PRO. This way, the software could be
developed before the hardware was ready. I have one of these
proto boards. There is a minor difference between programming it
and the real PRO bitmap -- two registers are swapped...
However, user programs doing direct access is frowned upon since
the display could get really garbled if every application which
wanted to did so... So there were a set of library routines which
were supplied with RT-11 which implemented GIDIS. This is essentially
the same GIDIS which was distributed with P/OS.
Megan Gentry
Former RT-11 Developer
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| Megan Gentry, EMT/B, PP-ASEL | Internet (work): gentry!zk3.dec.com |
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Received on Tue Jan 12 1999 - 09:55:44 GMT