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Hardware Documentation - Machines DEC - VAX hardware reference

This is an (incomplete) list of Digital Equipment Corporation VAX computers and specifications. Compiled by abs@NetBSD.org with much help from port-vax@NetBSD.org users.

This is very much still a work in progress - many sections are little more than placeholders. Having said that, there should be enough here to prove useful.

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Busses and interfaces

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Type: bus Used in: VAX 700, 6000, 7000, 8000, 9000, and 10000 series
Last updated: 1998-01-24
Type: storage device interface Used in: MicroVAX 3300/3400, VAXft, 4000, 6000, 7000, 10000 series
Last updated: 1998-01-28 Notes: A disk interface superseded by SCSI
Type: storage device interface Used in: VAX 700 series via SBI nexus. Used for attaching disks and tapes
Last updated: 1998-01-24
Type: bus Used in: VAXstation 3520, VAXstation 3540
Last updated: 1998-01-28 Notes: CPU, memory, I/O, graphics and Q-bus-adapter were on M-bus modules. Synchronous
Type: bus Used in: Most MicroVAXes, PDP machines, and some MIPS based DECstations
Last updated: 1998-01-24 Notes: 22 bit
Type: bus Used in: VAX 700 series
Last updated: 1998-02-07
Notes: "Synchronous Backplane Interconnect" to which sixteen NEXI may be connected. A NEXUS (singular for NEXI) may be a processor, UNIBUS Adapter (UBA), memory controller (and memory), or a high speed channel for disks/tapes (MASSBUS Adapter or MBA). Limited in length to three meters or less and is terminated on one end by the processor and on the other end by a terminator board
Type: storage device interface Used in: RA series disks, eg: RA80
Bandwidth: Around 4MB/s Last updated: 1998-02-06
Notes: "Standard Drive Interconnect" Referred to as "A balanced-serial phase-encoded horror", designed to stop charge buildup at either end. Used four lead coaxial cable. Multiple types of cables - one from KDA50 to 4 male SDI plugs mounted in host system, thick black 'liquorice strap' female to female cable between host and drive housing, then thinner white male to female cables between the drive housing and the drive itself. Cables swap pins so you must have an even or odd number of cables dependant on the drive. Cables were allowed to be up to either 15 or 30 meters
Type: storage device interface Used in: Generally VAXstations had SCSI built in or as a daughter card
Last updated: 1998-01-28 Notes: Other machines had SCSI adapters on Q-bus or similar cards
Type: storage device interface Used in: RD series disks, eg: RD54
Last updated: 1998-01-28 Notes: Also referred to as 'MFM' (though that is a drive encoding)
Type: bus Used in: VAXstation 4000, most MIPS based DECstations, and early Alpha machines
Last updated: 1998-01-24
Type: bus Used in: VAX 700 series via SBI nexus, PDP-11
Last updated: 1998-02-08
Type: bus Used in: VAX 6000 and 8000 series
Bandwidth: Around 13.3MB/s Last updated: 2000-02-15
Notes: Maximum bandwidth 13.3MB/s, max. 16 VAXBI nodes, used as main bus on 82xx/83xx.
Type: bus Used in: VAX 6000, 7000, 9000, 10000
Last updated: 1998-01-24

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