Technical data

Device Support on OpenVMS Systems
7.8 New Values for Length Parameter in System Routines (Alpha Only)
IOC$K_BYTE (hex 100) Right-Aligned Byte
The byte is always in the right-most lane:
+---+---+---+---+
| | | | X | bits <1:0> = 0,1,2,3
+---+---+---+---+
Note that the high-order byte contains unpredictable data and must be masked to
operate correctly.
IOC$K_WORD (hex 200) Right-Aligned Word
The word is always in the right-most lane:
+---+---+---+---+
| | | XXXXX | bits <1:0> = 0,1,2
+---+---+---+---+
Note that the high-order word contains unpredictable data and must be masked
to operate correctly.
By using the new values for the length parameter, programmers who write device
drivers no longer have to put data into the correct lanes before writes and after
reads.
7.9 ISA_CONFIG.DAT Unsupported in Future Release (Alpha Only)
V7.1
Support for using the SYS$MANAGER:ISA_CONFIG.DAT file to configure ISA
devices will be discontinued in a future release of OpenVMS Alpha. If you
use this file, you should convert both to using the ISACFG utility from the
console and to using the new file-based autoconfiguration method for loading
device drivers (as described in OpenVMS System Manager’s Manual, Volume 1:
Essentials).
7.10 Required Change in ISA_CONFIG.DAT on AlphaStation
200/400
V7.1
Customers configuring ISA devices on AlphaStation 200/400 Family systems
must change their SYS$MANAGER:ISA_CONFIG.DAT file, so that the node
information for each device appears at the end of each device description block.
Warning
For upgrades from OpenVMS Version 6.2 or 7.0 systems, this change
must be made before starting the upgrade procedure.
7–6 Device Support on OpenVMS Systems