qd(4)qd(4)Nameqd - VCB02 (QDSS) video subsystem
Syntax
device qd0 at uba0 csr 0177400 flags 0x0f vector qddint qdaint qdiint
Description
A VCB02 provides a half-page or full-page user-accessible bit map dis‐
play for graphics applications. The device consists of a 256kb Q22 bus
memory array, a 15-inch or 19-inch video monitor, and a VX10X-EA mouse.
The subsystem device driver supports a hybrid terminal with three minor
devices. The first device emulates a glass tty with a screen that
appears as a 120-column by 80-row page that scrolls from the bottom.
This device is capable of being configured as the system console.
The second minor device is opened in the raw mode by default. Opening
the second device makes the driver function like a pseudoterminal in
that the output destined for the first minor device is channeled to the
second instead. Input and output on the first two minor device numbers
are processed by the standard line disciplines.
The third minor device number is reserved for the mouse. This device
is a source of mouse state changes. (A state change is defined as an
X/Y axis mouse movement or button change.) When opened, the driver
couples movements of the mouse with the cursor. Mouse position changes
are filtered and translated into cursor position changes in an exponen‐
tial manner. Rapid movements result in large cursor position changes.
All cursor positions are range checked to ensure that the cursor
remains on the display.
If there is a VCB02 module at the standard address, the system will use
it as the system console. All input/output destined for will use the
VCB02 instead. (This is done by overwriting the device switch tables.)
There is a second set of device switch entries configured for the con‐
sole that can be used as an additional terminal or printer port by mak‐
ing a special device file using major number 38 and minor number 0 and
making the appropriate entry in
FilesSee Alsotty(4), ttys(5), MAKEDEV(8)
VAX qd(4)
