[HECnet] SSD for Vax

[Michael Young]

Back when I had RSX 11M+ on a 11/44 with massbus, I looked and looked for a ML-11 to try out. Never did find one. The application was electron-beam lithography, we were trying to write holograms, and under certain conditions the hardware was always waiting around for the pattern data from the disk. We also ended up doing on-the-fly data decompression to reduce the size of the pattern on the disk, which made the throughput situation *worse*. (That's when I discovered "fast-mapping" under M+, which is by the way very cool.)   The ML-11, had I been able to find one, might have helped significantly.

--Mike

On Oct 11, 2013, at 10:27 AM, Cory Smelosky <b4 at gewt.net> wrote:

On Fri, 11 Oct 2013, Johnny Billquist wrote:

On 2013-10-10 18:39, Hans Vlems wrote:
DEC had solid state disks, all das iirc

DEC had solid state disks already in the 70s. It was called the ML-11. Massbus interface even...


Now THAT is neat.

	Johnny

On 2013-10-10 09:46, Mark Wickens wrote:
On 10/10/2013 08:17, Daniel Soderstrom wrote:
Has anyone tries this? Running my Vaxstation non-stop reminds me how
much noise these old drives make.

Has anyone tried SSD drives? Must be good for the PSU it terms of heat
and current draw.

Daniel

There has been very little success with IDE to SCSI converters on this
age of machine.
Hmm. bad IDE to SCSI converters?

Remember also that even 4000/90 vintage VAXstations generally have an
upper limit of 18GB.
Uh? That got to be a limit in VMS in that case. I can't see how the
hardware would have that limit.

I don't recall anyone even getting an IDE drive to work, let alone an
SSD.
IDE and SSD are two completely unrelated things as such. However, if the
SSD have an IDE interface, then you obviously need the IDE to SCSI
converter.

Would love to be proved wrong however! I'm surprised someone hasn't
written a software based SCSI drive emulator the same way that you get
floppy emulators.
Probably mostly because of speed issues. You have some very tight timing
requirements, and a SCSI interface runs way faster than a floppy.

Consider running the machine diskless, booted off the network with
off-node disks.
That definitely also works.
Johnny
--


Cory Smelosky

Michael Young
young at ecn.purdue.edu