RFC 190 (rfc190) - Page 2 of 16
DEC PDP-10-IMLAC communications system
Alternative Format: Original Text Document
RFC 190 DEC PDP-10 -- IMLAC COMMUNICATION SYSTEM 13 July 1971
However, the IMLAC is barely able to keep up with the PDP-10
without this feature, so we were able to persuade the manufacturer
to implement it.
While no special hardware is required for the software described
here, the character interrupt and the SRI-ARC "mouse" and "keyset"
are highly recommended, and the software is oriented towards their
use.
(II) Facilities.
Each display console in the system may be in "display mode" or
"teletype simulation mode".
In display mode, the information displayed consists of text
strings at arbitrary positions on the display face.
In teletype simulation mode, the display shows the last 20-30
lines which would appear on a teletype listing.
A given console may switch between these modes, under program
control, without losing any information.
Regardless of mode, each display has a cursor string which follows
the position of the available pointing device,
The implemented system uses a "mouse" generally, but one console
uses a tablet.
The cursor string may be set by a program, for example to indicate
at what sort of object the user is expected to point.
In display mode, the screen of a given console is allocated to users
in rectangular blocks called "display areas".
This allows users to communicate via a single display split into
multiple areas.
When a user (program) requests a display area, he specifies how many
text strings he will want to display in it.
Each string has its own X-Y location, character size, font
(italic, underline, ...), and an arbitrary number of characters.
Each of these components is settable without disturbing the
others.
Each string may be manipulated without affecting the others.
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