XVS100(8)

NAME
Xvs100 - X window system VS100 implementation notes

DESCRIPTION

The VS100 implementation of X was the first, and is complete. Many of the X output operations are in fact modeled on the interface provided by the VS100 firmware. The VS100 is a monochrome display, 864 bits high and 1088 bits wide. The firmware we are currently using is version #235.

Cursors can be any size up to 64x64. Tiles can only be 16x16 in size. Brushes can be any size, but the current firmware draws wide lines about an order of magnitude slower than 1x1 lines. Off-screen storage is limited to that provided in the VS100 itself; no attempt is made to use DMA access to VAX memory for fonts and such or to dynamically shuffle data back and forth.

The keyboard is controlled by the VS100 firmware. Unfortunately, with the current firmware, the keyboard only gives up transitions for the Control, Shift, Lock, and Meta keys, so chord applications won't work.

At system boot, for some reason the first three attempts to down load the firmware fail. Thus, a VS100 won't become active until about 45 seconds after other terminal lines activate. Power-cycling a VS100 will cause the X server to restart. The down problem doesn't occur in this case, but typically a 3 minute TCP CLOSE_WAIT will occur.

SEE ALSO
X(8c), X(1)
`ddX - Device Dependent X Interface'

AUTHOR
Copyright (c) 1985, by Massachusetts Institute of Technology.