crassi@kodak.UUCP (charlie crassi) (05/11/88)
I need some help in answering a question about the RLL controllers !!
I recently added a harddisk to a PC 8000 clone by Franklin. I was given
a 10MB ST412 full height Seagate drive but the controller card was bad.
One of the guys I work with had an Everex 392 RLL controller which
works just super and gives me a little over 16MB Formatted.
My question is this:
I was told that the RLL controller will work fo about a month and then
will destroy the media which is not coated thick enough. Is there any
truth to the matter. I have talked to Everex in Freemont, Ca. and they
will not give me any answers one way or the other. They will not comment
past the standard retorek "we support the ST238, if it works on a ST412
we know nothing". Seagate has no comment at all.
--
thanks in advance ......... charlie
rutgers!rochester!kodak!crassi
\
ureka!charliepjh@mccc.UUCP (Pete Holsberg) (05/11/88)
In article <1255@kodak.UUCP> crassi@kodak.UUCP (charlie crassi) writes:
...I need some help in answering a question about the RLL controllers !!
...
...I recently added a harddisk to a PC 8000 clone by Franklin. I was given
...a 10MB ST412 full height Seagate drive but the controller card was bad.
...
...One of the guys I work with had an Everex 392 RLL controller which
...works just super and gives me a little over 16MB Formatted.
...
...My question is this:
...
...I was told that the RLL controller will work fo about a month and then
...will destroy the media which is not coated thick enough. Is there any
...truth to the matter. I have talked to Everex in Freemont, Ca. and they
...will not give me any answers one way or the other. They will not comment
...past the standard retorek "we support the ST238, if it works on a ST412
...we know nothing". Seagate has no comment at all.
Your data is living on borrowed time! Any medium which is not certified
for RLL will eventually fail (unless you are VERY lucky!) because of the
demands an RLL controller makes on it. The horror stories told on
CompuServe were enough to convince me to stop using my Adaptec
controller with an ST-225. People have reported that they were not able
to reformat their disks with their MFM controllers after abandoning
RLL!! This is not to castigate RLL, but an RLL controller needs a drive
that can handle the storage density and waveform requirements.Paul_L_Schauble@cup.portal.com (05/12/88)
RLL controllers require a disk drive that has tighter specifications for
bit timing than the regular controllers do. This is effectively a requirement
for better signal to noise ratio in the disk head, analog electronics, and
clock circuitry. Many modern disks meet the requirements and work fine
even though they are not certified by the manufacturer.
As I recall, your disk is one of the older ones. It may appear to work, but
you will be operating with no margin for error. One day the room temperature
may be different or the line voltage a bit low, and you'll start getting
data errors. If you don't have important data on the machine, keep your
backups current and try it.
NOTE that there is now way to damage the disk drive or the media by using
an RLL controller. If it doesn't work, just go back to the regular one.
Paulchasm@killer.UUCP (Charles Marslett) (05/14/88)
In article <638@mccc.UUCP>, pjh@mccc.UUCP (Pete Holsberg) writes: > In article <1255@kodak.UUCP> crassi@kodak.UUCP (charlie crassi) writes: > ...I need some help in answering a question about the RLL controllers !! > ... > ...I was told that the RLL controller will work fo about a month and then > ...will destroy the media which is not coated thick enough. Is there any > ...truth to the matter. . . > Your data is living on borrowed time! Any medium which is not certified > for RLL will eventually fail (unless you are VERY lucky!) because of the > demands an RLL controller makes on it. The horror stories told on > CompuServe were enough to convince me to stop using my Adaptec > controller with an ST-225. People have reported that they were not able > to reformat their disks with their MFM controllers after abandoning > RLL!! . . . The real problem is the first one mentioned here -- if the media and electronics of the drive are not certified for RLL they might work (I have a drive that I used as an RLL drive for over a year with no problems and it will probably work fine for as long as my RLL certified ST-238 (several diagnostics report no defects and the MFM defect list was empty so I think the ST-225 is a bit better surfaced than most, though). On the other hand, the drive may work for a week or two then start showing up soft errors (that just slow you down) or an occasional hard error -- that goes away when you rewrite the data. Both of these conditions can lead you to think that it's working when it's not! And one day you discover that you can't boot, can't read any of your data files, AND 2 MBYTES OF STUFF YOU PUT TOGATHER LAST MONTH ISN'T BACKED UP!!??!! Not worth the risk. As far as damaging the drive, so far as I know the only way a controller can damage a disk drive is by driving the stepper too hard, and a new MFM card has all the same options to step at all those funny rates as the new RLL cards -- that is to say, had the guy who couldn't format his drive after using an RLL card been using a new WD controller with that same drive (and run a similar "fast" interleave and step rate) he would have found his drive died running the MFM controller. Sigh, you have to be careful of overrunning ALL the specs of old hardware and that's why you ought to put some weight to even silly certifications if the data is important. Talk to me about getting software upgrades from Microsoft that aren't readable on 4 out of 5 machines! Their duplicators or diskettes are substandard, I think. [All to reiterate my subject line -- just losing data is bad enough!] Charles Marslett chasm@killer.UUCP