Asynchronous Serial Communications Programmer's Reference Manual (32022-90052)

Appendix A 293
Comparing MPE/iX Systems to MPE V Systems
Software Characteristics
Software Characteristics
The following are differences between the ASC software and the
software that controls the ATP/ADCC:
• Changed functions. These are functions that have been implemented
differently in the ASC software (and/or the DTC) from the way they
are implemented for ATP/ADCC.
• Programming considerations. These are more functions that have
been implemented differently. However, these functions apply only
to programs written to control asynchronous devices.
• Functions no longer supported. These are functions that are
supported with the ATP/ADCC software which are not supported
with the ASC software.
• Related operating system changes. These are functions that are
supported on MPE V computers but are not supported on MPE/iX
computers.
NOTE The following pages document all known differences between the
functionality of ATP/ADCC software and the functionality of ASC
software. Some of the following differences are very detailed, but are
not likely to impact the migration of most customer sites.
Changed Functions
The following functions have been modified. See also “Programming
Considerations” later is this Appendix for features that have changed.
Echo Facility
Pressing [Esc] is no longer necessary to turn the echo facility on or off.
The MPE/iX :SET command is used now. The syntax used to turn echo
on or off is as follows:
• :SET ECHO = ON
• :SET ECHO = OFF
XON/XOFF Protocol
With MPE V, the XON/XOFF protocol is used, but certain cases exist
when the XON (DC1) and XOFF (DC3) characters are ignored.
Therefore, it is difficult to determine when these characters will be
acted on. With ASC software, these characters are always acted on
when the XON/XOFF protocol is enabled.