MicroVAX II

MicroVAX II
A MicroVAX II with an RX50 dual floppy drive
Summary
Announcement date:	14 May 1985
FRS date:	May 1985
Codename:	Mayflower
OS support (VMS):	MicroVMS V4.1M
Enclosure(s):	BA23, BA123, H9642
CPU Details
CPU name (VMS):	KA630
CPU name (console):	KA630
CPU module:	KA630
Module:	M7606 [1]
Number of processors:	1
VMS DCL CPU:	8
VMS DCL XCPU:	1
SID:	08000000
XSID:	01010000
CPU chip:	78032
CPU technology:	ZMOS
CPU cycle time:	200ns [2]
Instruction-buffer:	8 bytes [2]
Translation-buffer:	8 entries [2]
Cache:	None [2]
Compatibility mode:	No
Console processor:	CPU
Console device:	RX50 or TK50
Memory
Minimum memory:	1MB [1]
Maximum memory:	16MB [3]
Memory checking:	Parity
On-board memory:	1MB [1]
I/O
Q-bus:	1 @ 3.3MB/s [3]
LAN support:	optional [3]

The MicroVAX II was a small VAX, with the KA630 CPU‎‎ for its CPU. Its bus between the CPU and main memory was a special bus carried on over the back connectors as well as the CD interconnect of the QBUS backplane; it used the QBUS for its I/O bus.

Operating Systems

The following operating systems can run on the MicroVAX II:

MicroVMS / VMS

In version 4 of the VMS operating system there were two different subversions:

• MicroVMS - for the series of MicroVAX computers
• VMS - for all other VAX computers

Both versions differ in contents and packaging:

• MicroVMS software was distributed as set of numerous RX50 diskettes or on TK50 tape cassettes.
• VMS software was available on standard 9-track magnetic tape or on removable disks, e.g. RL02 or RA60.

From version V5.0 onwards there was no more special version for the series of MicroVAX computers.

MicroVMS Support for MicroVAX II Computers

MicroVMS V4.1 was the first version to support the MicroVAX II computer.

VMS Support for MicroVAX II Computers

Some of the 'full size' VMS V4.x versions include MicroVAX II support, too, see the following table for details:

VMS V4.x Support for MicroVAX computers
Version	Type	Date	MicroVAX Support	Save Set Info
V4.0	Full	23-SEP-1984	NO	---
V4.1	Update	11-JAN-1985	YES	VMS041.A: VMS041 / VMS041.B: VMS only / VMS041.C: MicroVMS only
V4.2	Full	12-JUL-1985	NO	---
V4.3	Update	9-JAN-1986	YES	VMS043.A: Common Files / VMS043.B: VMS only / VMS043.C: MicroVMS only
V4.4	Full	30-MAR-1986	YES	Integral part of all Save Sets
V4.5	Update	26-SEP-1986	YES	Same as with V4.3 (individual Save Sets)
V4.6	Full	15-JUN-1987	YES	Same as with V4.4 (integral part of all Save Sets)
V4.7	Update	29-OCT-1987	YES	Same as with V4.3 (individual Save Sets)

UNIX

Many UNIX variants were available for the MicroVAX II.

Digital Unix

Ultrix

CSRG BSD

• 4.3 BSD
• 4.3 BSD Quasijarus

NetBSD

Version 1.2 and higher of the VAX port of NetBSD can run on a MicroVAX II. I've even built some instructions using SIMH on how to do so, that may be adapted to a real MicroVAX but I don't have one to test with.

OpenBSD

OpenBSD can run on the MicroVAX II as well, later versions are better for timing issues... 4.4 is the current good version.

Emulation

The MicroVAX II is emulated in SIMH.

External links

• VAX 630 - documentation at Bitsavers
  • MicroVAX II 630QB Owner's Manual (AZ-GLCAA-MN)
  • MicroVAX II 630QY, 630QZ Owner's Manual (AZ-GL1AA-MN)
  • MicroVAX II Technical Manual, BA23 Enclosure (AZ-GLFAB-MN)
  • MicroVAX II 630QB Technical Manual (AZ-GLBAA-MN)
• MicroVAX II 630QY, 630QZ Technical Manual (AZ-FE06A-TN)
• SIMH information on the CPU in the MicroVAX II

References

[1] MicroVAX II 630QY, 630QZ Technical Manual. AZ-FE06A-TN

[2] "CVAX-based Systems", Digital Technical Journal, Vol 1 No 7, August 1988.

[3] MicroVAX Systems Handbook 1988. EB-30991-41

[4] VAX Systems Hardware Handbook -- VAXBI Systems. EB-31692-46