Maintenance Operations Protocol

The Maintenance Operation Protocol (MOP) is used for utility services such as uploading and downloading system software, remote testing and problem diagnosis. It was a proprietary protocol of Digital Equipment Corporation. MOP frames can be one of the following commands:^[1]

Command	Description
[memory load data]	Contains memory load data.
[mem load request]	Request for memory load segment.
[mem load w/addr]	Memory load with transfer address.
[par load w/addr]	Parameter load with transfer address.
[dump service req]	Request for assistance with dump operation.
[mem dump request]	Request for next memory dump segment.
[memory dump data]	Contains memory dump data.
[dump completed]	Acknowledgment of dump completion.
[volunteer assist]	Offer of dump/load/loop assistance.
[request program]	Request for system or loader program.
[rem boot request]	Request for boot program.
[remote ID reqst]	Request for remote console identification.
[remote system ID]	Remote console identification information.
[counters request]	Request for communication information counters.
[counters reply]	Communication information counters.
[reserve console]	Remote console in reserved state.
[release console]	Release of remote console from reserved state.
[rem console poll]	Poll of remote console for status.
[rem console rply]	Response to remote console poll.
[loopback request]	Request to loopback enclosed data.
[loopback reply]	Response to loopback request with data.

References

^ http://www.protocols.com/pbook/pdf/decnet.pdf ^{[bare URL PDF]}

Digital Equipment Corporation

Key people

Ken Olsen (founder and CEO, 1957–1992)
Harlan Anderson (co-founder)
Gordon Bell (VP of engineering)
Robert Palmer (CEO, 1992–1998)

Instruction set
architectures,
processors

PDP-11	LSI-11 F-11 T-11 J-11
VAX	V-11 MicroVAX 78032 CVAX SOC Rigel Mariah NVAX
Alpha	Alpha 21064 21066 21068 Alpha 21164 (21164PC) Alpha 21264 Alpha 21364 Alpha 21464
Other	MicroPRISM StrongARM