Console Driver Interface
Overview
The Model 90 console code is split into a class/port driver scheme.
The class driver contains the main console functions, such as
PUTCHAR and GETCHAR. The port drivers contain the device
specific code required to support these functions. Figure 2–10
shows the division of the console function.
Figure 2–10 Model 90 Console Structure
LJ-01821-TI0
Console Class Driver
DZ Console
Port Driver
LCSPX Console
Port Driver
NI Console
Port Driver
Serial Line
Controller
LCSPX
Controller
Lance
Device
Input
I
O
O
I
O
Performing I/O
The console device can require either one channel or two channels
to perform I/O to the console device. If the console device is a
graphics terminal with a LK401 keyboard, the console program
must interface with the serial line device driver for console input
and interface with the graphics device driver for output from the
console. If the console device is a terminal connected to a serial
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