DRL DIO (octal 1) - do I/O on user's file.

Usage:

drl    dio
<seek command>
zero   l(fileid),l(dcw1)
<read/write command>
zero   l(fileid),l(dcw2)
zero   l(stat),0

Where:

fileid

is two words containing the file name in lower case ASCII, one to eight characters with trailing blanks.

dcw1

is defined by "IOTD l(rbn),1".

rbn: contains the relative block number set by the user (for random files). This word is always altered by I/O routines. The block size for random files is 64 words. Blocks within the file are numbered consecutively from zero.

dcw2

is defined by "IOTD l(data),n".

data: contains the starting address at which data is to be read/written.
n: is the number of words to be transferred. The maximum is 4096 words.

stat

is the status return location (two words long). Refer to the I/O Programming manual for status codes.

<I/O commands>

The user need not be concerned about giving commands for a specific device type because the seek (34), write (31), and read (25) commands are accepted for all devices. The actual commands used will be acquired for the particular device. The respective GMAP mnemonics SDIA, WDIC, and RDIC may be used for these commands.

Description:

DRL DIO is provided for files that appear in a user's list of files (AFT). It is the equivalent of the MME GEINOS and performs the indicated seek, read, or write using the master-mode routines. The subsystem is not eligible for execution until the I/O is complete. Time Sharing disk I/O issued on behalf of a user is considered roadblocked until all I/O completes.

For further information, see the Time Sharing System Reference Manual.