clark@ssc-vax.uucp (Roger Clark Swann) (06/06/91)
I have a custom data collection system that is based on a VME system,
off the shelf CPU, off the shelf SCSI card. The system this currently
operated with an Archive DC600 type 1/4 inch tape unit for storing data
via the SCSI bus. I would like to replace the 1/4 inch tape unit with a
DAT unit that could be placed in a 3-1/2 inch drive bay.
- Does any vendor make a DAT that will fits in a 3-1/2 inch bay ??
All I really want/need is the bare drive in a 3-1/2 inch form
factor. If I have to, I can go with a 5-1/4 inch unit in an
external case ( the 1/4 inch tape unit is that way now ).
- What is involved in converting to DAT from the 1/4 inch tape device ??
Any changes in software, etc. The system runs on its own
custom operating system.
- I am having trouble getting specs and such on DAT devices. I have
found that Archive sells them, but can't get info from my local
dist. and can't find a phone number for Archive. I know Sony makes
DAT. How about a contact for them? Other vendors for DAT? I think
there must be several. I DON'T need a system that is packaged with
a bunch of S/W and such, since the S/W would be useless to me. The
exception would C source code and linkable modules.
- And a last question; How about the write speed/time of the DAT
compared with the 1/4 inch tape unit? For my application, total
time required to store a 4 Meg file must be as short as possible,
since data collection is stopped during a tape write.
----------------------------------------------------------------------
Roger Swann | uucp: uw-beaver!ssc-vax!clark
@ | fax: 206-773-1249
The Boeing Company | voice: 206-773-5491kev@hpcpbla.HP.COM (Kevin Jones) (06/07/91)
> Does any vendor make a DAT that will fits in a 3-1/2 inch bay ?? HP Archive corp I assume you mean 3.5" "form factor" which in the real world measures 4 inches wide x 1.6" high x 6" deep (all measurements approximate - I'm sitting here with a worn ruler). > What is involved in converting to DAT from the 1/4 inch tape device ?? Its entirely dependant on what sort of SCSI commands your system is sending to the tape device. You might get lucky and not have to change any of your system software but don't count on it. > I am having trouble getting specs and such on DAT devices. I have > found that Archive ........ (uugh..... he's used the A-word - but I would say that :-) HP also manufactures DAT drives. HP/SONY pioneered the DDS format on which HP, SONY, ARCHIVE, WANGDAT, WANGTEK drives are based. HP has 3 products: HP35450 5.25" full-heigh DAT drive. HP35470A 3.5" half-height DAT drive. HP35480A 3.5" half-height DAT drive with built in data compression. (the 3.5" products are very new. You might well encounter blank expressions when you ask about them). > I DON'T need a system that is packaged with a bunch of S/W and such > since the S/W would be useless to me. In which case you will have to go to a distributor. Unless you pay premium for a boxed drive with power-supply, fan software, pledges of support etc (more $$$) then "one off" sales just ain't worth it for the manufacturers. > And a last question; How about the write speed/time of the DAT > compared with the 1/4 inch tape unit? HP35450, HP35470A = 183Kbytes/Sec. Approx 11 Mbytes/min. For a 4 meg file, a ball-park figure of about 30 seconds sounds about right. The HP35450 supports only 60 meter DAT tapes and can store approx 1.3Gbytes per tape. HP35470A supports 60 and 90 meter tapes and can put 2.0Gbytes on the 90 meter tape. HP35480A (ie. a '470A with data compression) will "go faster" if your data is "compressible" (ie. if there is a lot of redundancy in the data). With VERY redundant data it can easily get up to 1 Mbyte/Sec. Most computer data is nowhere near this redundant but a "custom data collection system" might/might-not produce exiting/dissapointing results. ----------------------------------------------------------------- Kevin Jones. | Hewlett Packard Ltd, | Computer Peripherals Bristol, kev%hpcpbla@hplb.hpl.hp.com | Filton Road, | Stoke Gifford, Tel: 011 44 272 799910 (ext 22351) | Bristol. BS12 6QZ. | ENGLAND. ----------------------------------------------------------------- This response does not represent the official position of, or statement by, the Hewlett-Packard Company. The above data is provided for informational purposes only. It is supplied without warranty of any kind.