16 Mar
2010
16 Mar
'10
5:23 p.m.
inline..
Peter Coghlan wrote:
Or a scsi baracuda drive in the 1.07gb or smaller range.
Anything less than 200mb is a force fit. 400mb or larger is comfortable
and over 500mb is room rich.
FYI those machines can accept typically 2 and often 3 scsi drives inside
of the 3.5" form factor.
Mine have 1gb for boot drive (dua0) and larger drives for userpace and swap.
Even adding a second 50-200mb drive is useful and can be used for
swpspace and user space.
But
practically, what this means is: No Money. Ergo, I can't afford to
buy any new bits. The reason I got this machine was its extreme
cheapness! (Under a pound - for Colonial types, that's about a buck
sixty.)
With any luck it may be possible to scrounge an RZ26 for a similar
price to the machine.
Well, what
size of disk would I want? I may have some 500MB units
knocking around, possibly bigger. The problem now is finding ones
/small/ enough, not big enough!
I've managed to crowbar a bootable subset of VMS 5.5-2 into 70MB.
It was so long ago I don't remember if this included any Decwindows
functionality. More recent versions with more fluff will probably
need more. 500MB would certainly be worth a try though.
Alternatively, use a disk larger than 1GB and hope for
the best.
You won't have lost anything if it doesn't work. When doing the
install, just install the critical items first, with the hope
of having everything that is accessed by the firmware ROMs for
boot appear below the 1GB mark. Opt not to have a dumpfile. The
biggest problem will probably making sure to get the index file
(which is used to locate all the other files on the disk) below
the 1GB mark. As far as I recall, VMS places the index file in
the middle of the disk by default but this can be overridden when
the disk is initialised. The only question is whether this option
is available when doing an install from scratch.
A lot of the early scsi CD RW drives will do the correct sector size
Toshiba and yamaha, I forget the one that begins with P (plextor?).
Is there any incantation I can type at the
firmware monitor to tell me
if it "sees" a device as a CD-ROM? Or is being seen as a CD no
guarantee?
SHOW DEVICE at the >>> should list the
devices on the SCSI bus. I don't
think it will tell you if the sector size is correct though. The only
way to be sure is to try it.
As far as I know, CDs containing a bootable and usable version of VAX/VMS
were not produced although they were for Alpha/VMS. A VAX would normally
boot the standalone backup program from a CD to do a VMS installation
rather than booting directly into VMS from the CD.
I have multiple 3100s and yes the connectors are weird and
the internal ones are the nominal 50 pin.
I don't wish to question authority, as it
were, but the internal
cables are 104 pin (If I'm counting them correctly) and the external
SCSI port on the back is 72-pin mini-D. That *looks* like wide SCSI to
me! If it's not, then what kind of cabling is it? The ordinary
narrow-SCSI stuff I knew from back in the '80s and '90s was 50-way
ribbon cables with 50-pin IDC connectors internally and either 50-pin
Centronics or D25 connectors externally.
The external SCSI connectors on a 3100 are rather strange. They are a
narrow SCSI bus presented on a male 68pin connector. It is definately not
wide SCSI even though it looks like it. To use it, the first thing you
will need is a cable with a female 68pin connector on one end and a 50 pin
centronics type connector (or something else reasonable) on the other.
Are there connectors for internal SCSI disks? They
should be normal
50pin IDC types.
A drive of 500mB for versions through 7.3 (by my expericnce) is more than enough
room.
Yes, but how do I *tell*, that's the
question!
I just picked up an IBM labelled CD drive off the floor. It has a
jumper at the back labelled "SECTOR SIZE". It's a fair bet that the
two sizes available are 512 and 2048. If you find a drive with a
sector size jumper, it will probably do.
When you say "a small-ish drive", what
counts as "small" for VMS? Or
rather, what sort of drive should I be looking for to /not/ have to
muck around when installing it?
1GB is more than adequate to install VAX/VMS. I remember 3100's used
to often come with an RZ23 which I think was 109MB. This was generally
regarded as too small to install a useful system on. I would have
a go on anything bigger than 200MB.
Not having to muck about probably involves spending a
little to get
an appropriate disk. On the other hand, having to muck about a bit
may will give you the experience you are looking for.
I'd suggest giving it a go with whatever you have.
define slow! ;) Depending on version and other things it may appear
more responsive than many would believe. Do not expect a cpu that is
many times faster than a 1993 486/33 to beat a PIII anything. However
you may find that line oriented text apps to be decent.
Allison
My hope is to get the machine booting into
DECwindows. I don't plan to
use it as a server, more as sort of glorified X-terminal if anything.
Recent versions of Decwindows are disk and memory hogs, especially on
VAX. It is likely that it will be very slow. It may be wiser to
concentrate on terminal based access initially at least.
Regards,
Peter Coghlan.