sm(4)
NAME
sm − small vax monochrome display subsystem
SYNTAX
device sm0 at uba0 csr 0x200f0000 flags 0x0f vector smvint
DESCRIPTION
A small vax monochrome display subsystem provides a half page or full page user accessible bit map display for graphics applications. The device consists of a 128kb block of dual port RAM, a VSXXX-AA mouse or VSXXX-AB tablet, and a 19 inch video monitor.
The model supported by the driver is a hybrid terminal with three minor devices. The first minor 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 reserved for the mouse. This device is a source of mouse state changes. (a state change 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 exponential manner. Rapid movements result in large cursor position changes. All cursor positions are range checked to insure that the cursor remains on the display.
The third minor device provides an access path for console output that does not disturb the graphics display. The caller can open the device /dev/smscreen. When this device is open, the small vax monochrome driver redirects console device output to the input buffer of this device. This mechanism disables console output on the small vax monochrome screen and saves the output for later display. This preserves the graphic display integrity.
Input and output on the first and third minor devices are processed by the standard line disciplines.
If there is not a special cable (BCC08) on serial port #3 (printer port), and the optional video board is not present (or failed the selftest), the system will then use the monochrome video as the system console. All input/output destined for /dev/console uses the monochrome video instead. (This is done by overwriting the device switch tables.) There is a second set of device switch entries configured which may be be used as an additional terminal, TIP/UUCP (hardwire, modem, or auto-dialer) connection, or user dialup access. For further information, see ss(4). The Hold Screen key is supported. The small vax monochrome driver treats this key as if ^S or ^Q is typed. Pressing this key suspends the output if it is not already suspended. The output will be resumed by pressing this key again (if the output was suspended).
FILES
/dev/console
/dev/mouse
/dev/smscreen