Asunto: Re: VAX-11/730

spedraja at spedraja at
Tue Apr 19 06:38:47 CDT 2005

Thanks, Ethan. This information is helpful by now.


>-- Mensaje original --
>Date: Tue, 19 Apr 2005 05:14:06 -0400
>From: Ethan Dicks <ethan.dicks at>
>To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at>
>Subject: Re: VAX-11/730
>Reply-To: Ethan Dicks <ethan.dicks at>,
>        "General Discussion: On-Topic and Off-Topic Posts"
>	<cctalk at>
>On 4/19/05, spedraja at <spedraja at> wrote: 
>> Hello everybody. I'm in the process to obtain one VAX-11/730. In appeareance
>> in working condition. I'm only waiting to know if it comes in "tower"
>> with a couple of RL02 units or not. Having this last in mind, I would
>> comments about the possible expansion of the system with other options:
>> (9-track unit(s) or Disks in SMD or SCSI format), memory, connectivity
>> and network ports, signal control ports), etc. If I remember well this
>> only had Unibus and not Massbus.
>There were two styles of 11/730, one with the CPU in the middle of a
>42" cabinet in its own 10.5"-tall drawer, and disks above and below
>(the most common configuration was an RL02 on top and an RB80 (121MB
>pseudo-SMD drive) underneath), and one with, IIRC, a BA-11-type drawer
>at the top of a 42" cabinet, and cable management space below (and no
>disks in the CPU cabinet).   I used to have one of the first type, and
>have never seen the second type except in pictures.
>The 11/730-Z (first type) has a backplane limited to 5MB of RAM, with
>room for a couple of other internal peripherals.  A common add-on was
>a DMF-32 (8 async, 1 sync, 1 printer).  The RL02 and RB80 were run
>from a special disk card in slot 1, and appear to VMS as DQA0: and
>DQA1:.  The machine is Unibus-only, and it _is_ possible to run a
>Unibus cable out and to an ordinary BA-11 with DD11-DK backplanes and
>the like.
>Being Unibus, one can attach 3rd party ESDI, SMD, and SCSI
>controllers, but I dare say you'll have quite a time locating an
>inexpensive Unibus SCSI controller.  It can talk to a DEUNA or DELUA
>Ethernet interface, but either of those might draw too much power to
>mount internally.  Same goes for a UDA-50.  The only compatibilty
>issue is power draw. If you have an external BA-11, you are good to go
>for these power hogs.
>You'll need a boot cartridge with this - just like the VAX-11/780
>powers up stupid, the 11/730 does as well.  Where the 780 has a PDP-11
>processor that loads up microcode and boot images and whatnot from an
>RX01 floppy, the 730 has an 8085 that loads things up from TU-58 tape.
> Check your tape drives for gooey capstans.  If the rubber seems like
>it's melting or turning into something that resembles a black
>jellybean, do *not* mount tapes.  You will have to refurb the drive
>first.  Tygon aquarium hose from the hardware store (.500"?) works
>well for this.  Your boot tape has to match the OS you'll be running -
>there were tapes for VMS and tapes for Ultrix.  I presume there were
>also tapes for BSD, but I only ever ran BSD on 11/750s, not 11/730s.
>The 11/730 (and 11/725) CPU rivals the MicroVAX-I for slowness (one is
>30% as fast as a 780, one is 40% as fast), but is a solid machine.  We
>used to use ours at work first for an office machine (MASS-11 and VMS
>MAIL) for a satellite operation, and later for a VMS 5.0 link machine
>for software development.  It would run for months at a time without
>problem.  The max memory is a bit limiting; I would be surprised if
>you could run VMS 6.x on it, but I know VMS 5.0 runs.  It was
>developed in the days where 2MB-3MB would suffice for a system with a
>small number of users, and was more-or-less rendered obsolete with the
>coming of the MicroVAX-II about 4 years later, with up to 16MB of RAM,
>a faster processor, 5.25" disks, and a much smaller box (but not a
>much smaller price tag, only slightly smaller).
>Good luck with it.  If you want to play with a Unibus VAX, it's the
>second smallest one, and not bad for a single-user VMS 4 or VMS 5
>Hope some of this helps,

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