What is the difference between MicroVMS and VMS?
MicroVMS is a special "downsized" version of VMS V4.x for the (at that time) new MicroVAX/VAXstation models. There were no other MicroVMS versions, neither before nor after VMS V4.x. The very first version of MicroVMS for the MicroVAX I was named MicroVMS V1.0, which sometimes leads to confusion. MicroVMS V1.0 is probably a kind of pre-release MicroVMS V4.0. All other MicroVMS versions were numbered exactly like their "big brothers".
Reasons that led to the fork of MicroVMS:
- Cookbook-Style Documentation
- Simplification of System Management
- Hardware restrictions
Reasons that made MicroVMS unnessary from VMS V5 onwards
- V4.0: 32 RX50 (without Mandatory Updates)
- V4.1: 3 RX50
- V4.2: n RX50 / 1 TK50
- V4.2MUP: 1 RX50 / 1 TK50
- V4.5: 16(Base)+25 RX50 / 1 TK50
- V4.6: 16(Base)+26 RX50 / 1 TK50
|Version||Type||Date written||MicroVAX support|
|4.1||Update||11-JAN-1985||YES: VMS041.A-VMS041 / VMS041.B-VMSONLY / VMS041.C-UVMSONLY|
|4.3||Update||9-JAN-1986||YES: VMS043.A-COMMON FILES / VMS043.B-VMS ONLY / VMS043.C-UVMS ONLY|
|4.4||Full||30-MAR-1986||YES (integral part of all Savesets)|
|4.5||Update||26-SEP-1986||YES: same as with V4.3 (individual Savesets)|
|4.6||Full||15-JUN-1987||YES: same as with V4.4 (integral part of all Savesets)|
|4.7||Update||29-OCT-1987||YES: same as with V4.3 (individual Savesets)|
DEC called MicroVMS "retired" from VMS 5.0 onwards
Wikipedia: MicroVMS was a distribution of VAX/VMS designed for MicroVAX and VAXstation hardware, which had less memory and disk space than larger VAX systems of the time. MicroVMS split up VAX/VMS into multiple kits, which a customer could use to install a subset of VAX/VMS tailored to their specific requirements. MicroVMS releases were produced for each of the V4.x releases of VAX/VMS and was discontinued when VAX/VMS V5.0 was released.