MicroVAX 3100 series

A MicroVAX 3100-80

The MicroVAX 3100 series was a line of entry-level desktop VAX minicomputer systems, all using a microprocessor VAX on a motherboard. (Several different VAX microprocessor implementations were used, over the life of the series.) Although they all had some I/O peripheral upgrades available, the list is limited; the 3100 was not built around a standard bus.

The CPU used was the KA41 CPU, KA45 CPU, KA47 CPU, KA50 CPU, KA51 CPU, KA55 CPU, KA56 CPU or KA59 CPU, depending on the model. Additional main memory was carried on daughter-boards in initial models; later SIMMs were used.

All models of the series supported SCSI for mass storage, as well as Ethernet and several asynchronous serial lines. Additional main memory, asynchronous serial lines, and synchronous serial lines, were available as options.

A desktop mounting box was used across most of the 3100 line; the Models 88 and 98 used mini-tower packaging. All models could run either VMS or ULTRIX-32.

The models in the series were:

• MicroVAX 3100 Model 10
• MicroVAX 3100 Model 10e
• MicroVAX 3100 Model 20
• MicroVAX 3100 Model 20e
• MicroVAX 3100 Model 30
• MicroVAX 3100 Model 40
• MicroVAX 3100 Model 80
• MicroVAX 3100 Model 85
• MicroVAX 3100 Model 88
• MicroVAX 3100 Model 90
• MicroVAX 3100 Model 90A
• MicroVAX 3100 Model 95
• MicroVAX 3100 Model 96
• MicroVAX 3100 Model 98

The Model 10 and Model 20 were very similar; the latter had a slightly larger mounting box.

The 3100's shared their motherboard and mounting box with the VAXserver 3100 series and VAXstation 3100 series.

Further reading

• The Design of the VAX 4000 Model 100 and MicroVAX 3100 Model 90 Desktop Systems, DTJ, Vol. 4, No. 3, Summer 1992 (pp. 75-83 of the PDF; a system block diagram on pg. 78 of the PDF)

External links

• VAX 3100 - documentation at Bitsavers
  • MicroVAX 3100 and VAXserver 3100 Owner's Manual (EK-A0371-OM-002) - covers Models 10 and 20
• EK- - contains a considerable number of rare (online) 3100 manuals
  • MicroVAX 3100 Model 85, 90, 95, 96 KA50/51/55/56 CPU System Maintenance (EK-M3100-SM.B01) - has a system block diagram on pg. 18 of the PDF (technical documentation on the 3100's is very scarce)
  • MicroVAX 3100 Platform KA45 CPU System Maintenance (EK-A0513-MG.001) - has a system block diagram on pg. 18 of the PDF
  • MicroVAX 3100 Platform KA47 CPU System Maintenance (EK-A0514-MG.001) - has a system block diagram on pg. 16 of the PDF
  • MicroVAX 3100/VAXserver 3100 Illustrated Parts Breakdown (EK-A0372-IP-003)
  • MicroVAX 3100 Platform Options (EK-A0519-MG.001)
  • MicroVAX 3100 Model 85/95 Installation Information (EK–A0716–IN.B01)
• MicroVAX 3100 Platform CPU Reference Information (EK-A0574-HR.001)
• MicroVAX 3100 Platform Options Supplement (EK-A0519-UD.D01)
• MicroVAX 3100 and VAXserver 3100 Options Installation Guide (EK-424AA-TS-001)
• MicroVAX 3100 Model 85/95/96 Operator Information (EK–A0717–OP.C01)
• MicroVAX 3100 Model 40 and Model 80 Customer Technical Information (EK-A0525-TD.001)
• MicroVAX 3100 Model 85/95 Customer Technical Information (EK-A0718-TI.B01)
• MicroVAX 3100 Model 85/95/96 Customer Technical Information (EK–A0718–TI.C01)
• MicroVAX 3100 Models 30/40/80 Supplement (EK–M3148–SI.A0)
• MicroVAX 3100 Model 40/80 to Model 85 CPU Upgrade Guide (EK–M3185–UP. A01)
• MicroVAX 3100 Model 40 to Model 90 Upgrade Guide (EK-A0612-UP.001)
• MicroVAX 3100 - covers the Models 88 and 98, in the mini-tower packaging
• MicroVAX 3100 and VAX 4000 Desktop Servers - marketing brochure
• DEC MicroVAX 3100 Model 20 - includes images of the cards