gay%elde.epfl.ch@cunyvm.cuny.edu (David Gay) (01/06/89)
I ordered a harddisk system from Spirit Technology at the LA AmiExpo, and
received it at the start of December. I payed 879$ for a 63meg harddisk
(This was a special(?) offer, you usually get a 40meg for that price). You
can also buy the interface alone (I can't remember the price offhand).
Introduction
------------
This is a "Wedge" style interface for the A500 or A1000, it allows you to
connect an IBM ST506 controller. Currently, it supports the OMTI 5520, 5527
and Western Digital WD1002A-WX1 or 27X (respectively MFM or RLL
controllers). They recommend the OMTI interfaces for speed. You can
have one or two drives connected. There is an optional Autoboot facility
(I haven't got it).
Hardware
--------
The actual interface fits inside a 20(h) x 8(w) x 15(d) cm (sorry, no
inches :-)) box and sits vertically with the IBM interface piggybacked on
it, and a hole for the cables at the back. There is a passthru. Power is
drawn from the power supply for the harddisk.
With their prepackaged systems, you get the harddisk itself, the power
supply and the fan already mounted, but you must install the interface in
the box. And here is the time to give out some Kudos: ST installed a 220V
transformer and fan in my system, even though I hadn't asked for it, hadn't
made any particular comments about this when ordering (in LA don't forget)!
And me who had been wondering where I was going to plug it in (I have a
220V->110V transformer, but it's in use ...).
I haven't had any problems with it, except when I let it overheat by
putting my external drive on the harddisk case. Since I've moved it off,
the problems have stopped (What happened was that the HD simply "stopped"
working, any reference to it brought up a R/W error requester w/o the disk
light coming on).
Documentation
-------------
The system came with a disk, the OMTI 5520/7 reference manual and a small
"instruction manual". Missing however, was any description of the HD, all I
know is that it is made by Miniscribe (and that by looking in the case)
:-(. Luckily, this didn't cause too many problems (see Software).
The "Instruction Manual" explains reasonably well how to assemble and
install the whole thing, create a mountlist, copy WB to the HD ... It
assumes you know at least how to use the CLI, and I feel that somebody who
doesn't know the Amiga well would need soome help to actually get
everything properly setup(eg having a floppy simply to boot, maybe setting
up RAD: ...).
Software
--------
There is a very "intuitionised" low-level format program, with one very
nice feature: it "pulls out of its hat" your drives parameters. This is
where I found out that I had an RLL drive with 820 cylinders, 6 heads, and
26 sectors/cyl (standard for RLL). Can anybody tell me what drive this is ?
(Made by Miniscribe, remember) and for that matter, were the program finds
this data ? (It seems to read them from somewhere: you see some default
values, eg 615 cyls ..., the HD light flashes, and there the parameters are
... I've just checked something: the last track (819) is unreadable. Future
enhancements ? (see further on)). After you've done the low-level format,
you can "verify" the harddisk for hard errors for all the good that it'll
do you. Nothing is done with this information :-( :-( :-(.
After this is done, and you've made a mountlist, you can proceed to format
the drive. Of course, this fails if you have any bad blocks, as there is no
bad block mapping. This happened to me. The documentation says to use the
QUICK option to format(I must say I missed this, and did something else).
Question: will this cause any problems (with all those un-AmigaDos
formatted tracks) ?
Finally, you can run a program called MapBAD which checks for bad sectors
and marks them as unavailable in the bitmap. All very well, but every time
your disk revalidates (this happens every few days, after all), a new
bitmap is created and the bad sectors are again available :-(. After a few
goes at this, I was quite fed up (It takes some time to scan 820
cylinders). What's even worse is that the documentation doesn't breathe a
word about this, and poor Joe Average would never guess till he got a R/W
error. This is *really* dumb.
Not being Joe Average (at least, I hope so :-)) I wrote myself two little
programs to deal with this problem: one called mapout checks a partition
for bad blocks, and allocates a replacement. Cylinder 0 is used for this.
mapbad SetFunction's the BeginIO vector of the device and checks for
requests containing bad blocks. It has worked well upto now. Maybe I
should send it to Spirit Technology ? :-)
Diskperf results
----------------
FFS OFS
File creations (files/sec) 31 14
File deletions (files/sec) 62 30
Directory scan (entries/sec) 96 43
Seek+read (seek+read/sec) 86 57
Read speed, 512 buffer (byte/sec) 28493 20805
Read speed, 4096 buffer (byte/sec) 145635 24966
Read speed, 8192 buffer (byte/sec) 201649 26214
Read speed, 32768 buffer (byte/sec) 291271 25450
Write speed, 512 buffer (byte/sec) 54613 27594
Write speed, 4096 buffer (byte/sec) 131072 34044
Write speed, 8192 buffer (byte/sec) 187245 35424
Write speed, 32768 buffer (byte/sec) 218453 34952
This with the disk half full (I got ~320'000 with the disk empty). Also,
the OFS partition had several bad blocks, necessitating seeks to track 0,
and back.
Question: why is a write faster than a read with a 512 byte buffer ???
I'm not sure what to think of these figures as I haven't got any comparable
ones (eg for the Wedge).
Conclusion
----------
In the present state of the software, I don't feel I can recommend this
system (Does anybody else sell a HD system which doesn't map out bad
blocks ?). Apart from that I'm satisfied (it's much better than floppies !
There's quite a lot of change between 512K, 2 floppies (one flakey) and
1.5Mb, 63Mb hard disk...).
Disclaimer: I have no connection with Spirit Technology, except as a
satisfied customer of their A1000 internal memory expansion board, and
mildly satisfied with their hard disk.
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David Gay Another mad amigan
GAY@ELDE.EPFL.CH, or GAY%ELDE.EPFL.CH@CEARN.bitnet
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