2955 adapter, a stripped-down variant of the 2701 communications controller. It could connect at 600 bit/s to the RETAIN system to run diagnostics. Mainly, this was to run mostly the same diagnostics that could be run locally by an IBM CE, but in time other specialized applications were developed, such as programs to analyze "logouts" generated by hardware malfunctions, i.e. "machine check" interruptions. In time, the concept of remote support was extended to software as well (about 1973 or 1974). Through a special application, an MVS system could be connected, via RETAIN, to an IBM support center, and memory dumps and other system data could be examined remotely. The application also permitted download of software fixes, or IBM Program temporary fixes. Although the 2955 only supported a 6-bit character code (similar to the 2740 terminal), binary transfer of memory dump and software updates was accomplished through a protocol similar to the base-64 encoding scheme used today on the Internet for email attachments. Over the years, several projects have aimed to supplant RETAIN's functionality, but it has shown lasting presence despite them. External links Database engines IBM software