I was staring at a Seagate "fiber channel" drive today and trying to
figure out what the most economical method of attaching a few to a box
would be. Seagate made a line of STxxxxFC drives with a small
D-connector (like a narrow SCA connector) that presumably has power,
unit ID lines, and, of course, the drive's part of the FC loop for
data in/out. I know there are a number of Sun boxes (3500? 5500?)
that have compatible connectors right there in the CPU box - you just
drop the drives into bays in the front of the machine and off you go.
Presuming you have something older, with PCI or Sbus, say, what
options are there for using these drives?
I know there are PCI (PCI-X?) FC-AL-over-copper SCSI controllers.
What has me puzzled is what the options are for the interconnects -
drive bays, external connections (copper vs fiber) for said bays,
copper-to-fiber converters, etc. If one wants to hang a wad of drives
off of a server, it seems that an 8-drive bay or whatever, with a
fiber attachment to an Sbus or PCI fiber card makes sense. If one
has, say, a PCI SCSI controller with an FC-over-copper external
connector, or just wants to hook up one or two drives, are there any
inexpensive interconnect options, like, say, the SCA-to-68-pin adapter
boards that are an inexpensive way to use an SCA drives in an non-SCA
environment?
Of course the answer might just be, "no... the drives are the cheap
part of an FC-based storage scheme", but given how cheap FC drives
seem to be these days (plus the added bonus of fiber-attached drives
being allowed to be a couple of kilometers from your server via
single-mode fiber ;-) it seems like an option worth exploring.
My direct FC-AL experience is a bit old - I used to run SPARCserver
1000 with three pre-FC-AL disk boxes with 3 drawers each of up to
seven 2GB SCA-connector drives. I think one or two members on the
list might have one of these. It was nice in its day (10+ years ago),
but a lot of juice and a lot of heat for your 42GB (you _might_ have
been able to install 4GB drives, but no larger due to firmware
limitations in the box). I did get to fiddle with what I think might
have been an early proper FC-AL box with a stack of 9GB drives, but I
didn't get to play with it long enough to have many details stick in
my mind about it.
For now, though, my best Sun box just has a couple of 18GB
SCA-connector drives. Effective, but boring.
Thanks for any info on FC-over-copper interconnects and adapters.
-ethan
A bit of a different post here, but I thought folks on this list might
get a kick out of the tattoo I had inked this week, branding me for
all eternity as one with retro computing in my blood (and on my skin).
A sort of crude petroglyph from the walls of the cave of computing history.
http://www.bytecellar.com/archives/000105.php
bp
--
Heisenberg may have slept here.
> If you have any comments I would like to hear them.
Do you have any other Memorex system documents?
I have a fair bit on the MRX 70 under http://bitsavers.org/pdf/memorex/7x00
but I didn't have the RPG design document.
All:
I?ve done a bit of searching for this but can?t locate it. Does anyone
have a scannable copy of the schematic for the Mockingboard sound board for
the Apple II?
Thanks.
Rich
--
Rich Cini
Collector of Classic Computers
Build Master and lead engineer, Altair32 Emulator
http://www.altair32.comhttp://highgate.comm.sfu.ca/~rcini/classiccmp
Hi guys,
I think I might be on something of a roll here - I spent the train ride
to/from work (and a good chunk of my lunch break) playing about with state
machine designs for the write side of the floppy disc writer. What I've come
up with is a nifty little finite state machine that interprets instructions
>from the acquisition RAM, then executes them and writes them to disc. The way
I've done it, there are five instructions:
0nnn nnnn: Write Timer. Writes the 7-bit timer value 'n' to the timer, then
outputs a pulse on the WRDATA line when the counter reaches zero
1111 1111: STOP. Sets the STOP flag and halts the state machine until it is
reset.
1011 xxx0: Close Write Gate. Deactivates WRGATE, preventing the head from
writing to the disc.
1011 xxx1: Open Write Gate. Activates WRGATE, allowing the drive head to
write to the disc.
110n nnnn: Wait for 'n' INDEX pulses before continuing execution of SM
instructions.
1100 0000: Wait for a hard-sector track index (sector zero marker) signal
before continuing execution of SM instructions.
As far as I can tell, this is the minimum instruction set required to allow
both soft and hard sectored discs to be duplicated reliably. There is one
'spare' instruction -- 1110 xxxx -- if anyone can come up with a good use for
it, I'm open to suggestions.
The write hardware currently clocks in at 19 macrocells, read hardware is
another 26, the track-index pulse detector (which allows hard-sectored discs
to be read and written) is 18, and the MFM synchronisation detector (including
the neat little state-machine data separator) is another 29. So that's a total
of 92, which leaves 52 for the acquisition control circuitry and registers.
Assuming I don't run out of any other chip resources first, that is.
The disc interface is going to be a standard 34-pin "PC" floppy connector.
It seemed like the best plan - wiring to 3.5 and 5.25" drives can be done with
a standard cable, and 8" drives can probably be connected with a fairly simple
adapter cable.
I do need one thing confirming though - I've read that on hard-sectored
discs, each sector is marked with an index pulse:
---+ +------------+ +----
| | | |
+--+ +--+
And the start of the track (sector 1) looks like this - note the index pulse
half-way between two other index pulses:
---+ +----+ +----+ +----
| | | | | |
+--+ +--+ +--+
1 2 3
My question is, does sector 1 start at 1, 2 or 3? I'm guessing 3, and that's
what the sync detector's set up for at the moment. Basically, it has a timing
window - if a second index pulse arrives within 0.75T (where T = time between
two normal index pulses) of the last one, it is assumed to be a track index
sequence. The threshold value is adjustable in software, so drive speed isn't
an issue.
Thanks.
--
Phil. | (\_/) This is Bunny. Copy and paste Bunny
classiccmp at philpem.me.uk | (='.'=) into your signature to help him gain
http://www.philpem.me.uk/ | (")_(") world domination.
How common were drives which could read these? I suspect the answer is "not
very"! If anyone has one, how reliable was/is the media?
I've got a couple of such Sony cartridges here dating from 1991; one does call
itself a data cartridge (QG-112M) - the other one is a PAL/SECAM 90-minute
Video8 tape (P5-90MP).
Going from the labels, both have backups from some UNIX system on them - but
(helpfully!) no clue as to what that system was or what backup program wrote
them. From the huge box of floppies that I found them in though, I suspect
that they might be from an Olivetti 3B2 - in which case they're possibly just
tar dumps.
I'm not sure what my chances are of finding a drive to read them are though
(and worse still, such a drive might not be SCSI and so require a proprietary
interface card and drivers). The packrat in me wants to try reading them
rather than just tossing them out though :-)
cheers
Jules
>There is a large pile of VAX and other documentation waiting for
>disposal on the 7th floor of Disque Hall at Drexel University in
>Philadelphia.
>Disque hall is located on the former 32nd street between market and
>chestnut streets, its the tall(~10 floors)) brick building.
>Pretty much everything paper, and a working Phaser 370? printer (missing
>its paper tray and missing the centronics->microcentronics adapter but
>otherwise working) is free for the taking.
>This documentation originally went along with the VAX machine which
>someone from the list rescued from there about 2 years ago when it was
>being disposed.
This is all still there. I found the VAX installation manual and license PAK buried in a seperate pile behind some fuzzy wall panels (I have it cached at home now), so there's also some networking manuals and other stuff behind there in grey binders in additional to the 22 orange binders of VAX stuff. This stuff IS going to be disposed of eventually, so I suggest anyone who wants it to get it QUICK. Theres also a bunch of printouts, schematics, software manuals, and source code listings for some old CERN-associated neutrino experiment which was run years ago, if anyone is interested in that.
Jonathan Gevaryahu
We are probably going to be drastically curtailing our museum efforts and perhaps shifting to a new
affiliation if I can pull it off. As a start to lightening the load we are scanning as many of the
manuals as we can. (We have a pretty nice scanner and some office assistants who occasionally have
extra time that they need to look busy in.) I will be placing the scanned manuals on our web site,
but for the time being there will be no link to the directory. You may feel free to download any of
them you like. If you want to download everything that will be OK, but try to do it in the early
morning hours U.S. Central Standard time. The university has a pretty good connection, but we don't
want to swamp it during the day.
If you seen anything that you would like to have in hard copy I will be happy to mail it to you.
Payment of the postage and some token payment for the manual would be appreciated. You can contact
me via email to arrange such a payment.
If you see anything here that you think should not be available because of copyright limitations
please let me know. I assume that since these manuals are all nearly 30 years old that nobody will
care. Of course something may slip through the cracks and some large vendors still exist and might
care for legal reasons, but I don't have time to sort that all out right now.
Here is the link:
http://www.cse.uta.edu/TheMuseum at CSE/Manuals%20Scanned/
If you have any comments I would like to hear them.
Gil
--
A. G. (Gil) Carrick, Director
The Museum at CSE
University of Texas at Arlington
Department of Computer Science & Engineering
Box 19015, 471 S Cooper Street
Arlington, TX 76019
817-272-3620
http://www.cse.uta.edu/TheMuseum at CSE/
> I've never seen an audio cart used in a data drive,
> and we had a lot of customers using them..
Audio DATs don't have the media recognition burst, and will
be rejected by DDS drives.
DDS tapes used as audio DAT tapes overwrite the DDS data, and
are unusable as data tapes after doing that.
Early audio DAT recorders (TEAC DA-30) will accept 90M data tapes,
later TEAC drives will reject them. At one point we had about 6
DA-30's at KFJC, which have all developed transport problems after
using a lot of 90M data tapes in them.
We're slowly migrating 100's of DATs to optical or IDE disc media
because of the problems preserving data recorded to DAT.
