Owner`s manual
Page 6-10 Chapter 6
After the computer is up and running, the SYSTEM command performs a new function
as a user command telling you what programs are in system memory and the total size
(in decimal bytes) of the monitor.
6.9.1Including Device Drivers in System Memory
All SCSI drivers for non-DSK devices, and all AM-219 device drivers, must be loaded in
system memory.
There is one other situation in which you MUST include device drivers in system
memory: If users on the computer will be accessing a device that is not the System
Device from within AlphaBASIC or AlphaVUE, you must preload the driver for that
device into system or user memory before using AlphaBASIC or AlphaVUE, or the
device access will fail.
The reason for this is that to perform their special functions, AlphaBASIC and AlphaVUE
have to handle their own memory setup—however, because of this, once AlphaBASIC
or AlphaVUE is run, there is no room in memory to load a device driver.
For example, users often access the generalized terminal driver, TRM.DVR, within
AlphaBASIC or AlphaVUE using statements similar to these:
OPEN #100,"TRM:TRM6",OUTPUT
or
> Unyank TRM:TRM6
If this is true on your computer, remember to keep TRM.DVR in system memory or
preload it into user memory before using BASIC or VUE.
You may want to load the driver programs for all the devices you use on your computer
into system memory, so they will always be available.
6.9.1.1Setting Up Write Buffering
Write buffering can increase system performance by making the process of writing data
to the disk more efficient. When write buffering is on, the system stores data to be
written in a buffer in memory and writes it to disk in larger segments rather than one
block at a time. It waits to write until the disk is not busy, or until a time limit you set.
You can use write buffering on any AMOS system which uses an "enhanced" SCSI
dispatcher (SCSI dispatchers are discussed earlier in this chapter). You set up write
buffering by adding the /N option to the SYSTEM statement loading your disk device
driver in system memory. The format is:
SYSTEM DVR:dev/N buffer-size flush-time
System Operator’s Guide to the System Initialization Command File, Rev. 03