Console Driver Interface,
Continued
line, the console responds to the serial line driver for both input
and output.
The console class driver contains the generic routines that
interface to the console and user application to perform terminal
input and output transactions. The console class driver interfaces
with the port driver depending on the current console device.
If the console port driver does not support PUTCHAR or
GETCHAR functions, it must interface with the appropriate
port driver to perform the needed function.
Shared
Console
Interface Area
The shared console interface area (SCIA) consists of a console
class driver descriptor and three port driver descriptors. The
port driver descriptors can be associated with a DZ port driver, a
graphics output driver, and a network driver.
The SCIA provides an interface to the console terminal that
isolates the implementation specifics of accessing the console
terminal. It is designed so the console drivers can run in both
virtual and physical mode.
The SCIA is set up by the initialization code. After the SCIA is
set up, the software can use this area to interface with the console
class driver routine. The shared console performs the following:
Raw character I/O to console terminal
Higher level of I/O functions that handle XON/XOFF flow
(ASCII bell character and LK401 keyboard translation are
handled by the DZ driver.)
Data structures to allow system software to map all console
code and I/O space references into virtual memory as needed
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