[comp.sys.atari.st] 70 folder limit?

atwell@utah-cs.UUCP (01/27/87)

Sorry to post one more on the 40 folder dead horse, but I got the
February issue of Byte today.  As part of its review of the 1040ST,
it had a page on the hard disks available for the ST.  Here's a quote
from that page:

	"Although the 1040ST's ROMs allow for only 40 folders on a disk,
	 the SupraDrive's boot software installs a patch that allows 
	 up to 70 folders."

This sounds crazy from what's been posted here.  Is it true?

Bart

	

oyster@uwmacc.UUCP (01/27/87)

In article <4215@utah-cs.UUCP> atwell@utah-cs.UUCP (Bart L. Atwell) writes:
>Sorry to post one more on the 40 folder dead horse, but I got the
>February issue of Byte today.  As part of its review of the 1040ST,
>it had a page on the hard disks available for the ST.  Here's a quote
>from that page:
>
>	"Although the 1040ST's ROMs allow for only 40 folders on a disk,
>	 the SupraDrive's boot software installs a patch that allows 
>	 up to 70 folders."

   There are a couple possible problems with this.  First is the general lack
of accuracy of most BYTE articles I've read concerning the ST(s).  For example,
the same article states that if you're accessing a certain folder, you can't
access any other folders on that disk.  Anybody who's sat in front of an ST for
more than a few minutes knows that's just not true.  Secondly (Alan Pratt
probably won't like this), the word from a BIX developer is that the folder
problem seemed to occur around 80, so they decided that half of that was
a "safe" number.  I stress that this was merely what a knowledgable BIXer
stated he got as second-hand info, and that it isn't the official Atari word.
--

 - Joel ({allegra,ihnp4,seismo}!uwvax!uwmacc!oyster)

Disclaimer:
   The above, unless otherwise labeled, constitutes personal opinion.

grunau@husc4.UUCP (01/28/87)

In article <968@uwmacc.UUCP> oyster@unix.macc.wisc.edu.UUCP (Vicarious Oyster) writes:
>
>   There are a couple possible problems with this.  First is the general lack
>of accuracy of most BYTE articles I've read concerning the ST(s).  For example,
>the same article states that if you're accessing a certain folder, you can't
>access any other folders on that disk.  Anybody who's sat in front of an ST for
>more than a few minutes knows that's just not true.  Secondly (Alan Pratt
>probably won't like this), the word from a BIX developer is that the folder
>problem seemed to occur around 80, so they decided that half of that was
>a "safe" number.  I stress that this was merely what a knowledgable BIXer
>stated he got as second-hand info, and that it isn't the official Atari word.
>--
>
> - Joel ({allegra,ihnp4,seismo}!uwvax!uwmacc!oyster)


This comment about Byte inaccuracy reminds me of one of those nagging questions
that have been itching at me increasingly for a while now.

The major thrust, if I remember properly, of those Byte articles, is that what
made the ST special, compared to the other 68000 machines around, is that, in a
sense, whereas the Mac was built for user-friendliness, and the Amiga for
flashy graphics, the ST was built for _speed_.

In fact, they make a fair point of stressing that the ST disk ports are about
the fastest around.  If you look at the right specs, this seems to be true --
for instance, Byte lists the top speed of data transmission of the DMA port
at about twice the top speed of the Mac Plus's SCSI port (I forget the
figures).  Furthermore, one of the ST articles actually says that most hard
disks for the 512K Mac transmit at a speed barely above the ST's FLOPPY
ports, and that (this is the crucial item) the Mac's (serial) floppy ports
transmit at only a bare fraction of the blindin speed of the ST's (parallel)
floppy ports.

Now, I should say that this was one of the original pieces of information
that attracted me to the ST.  I find working with a floppy-based Mac about
as pleasant as I would imagine having boiling acid dripped into my eyes --
after a while, the room spins along with the incessant whirring of the
floppy drives, which seem to take about 75% of your time.  Furthermore,
my introduction to the Amiga was equally unpleasant -- if anything, judging
by the speed that a Window displayed its icons, Commodore seemed to have
achieved the impossible:  floppy accesses even SLOWER than a Mac's.  So
when Byte happily informed me that the ST's architecture, with its DMA
chips and its glue chip and its high-speed ports and its 8 MHz clock rate,
was a speed-machine, I thought "this is the 68K for me!".

Now, however, I am really beginning to wonder.  Outside of Magic Sac usage,
I hardly ever need to use floppy accesses since I have a HD.  But floppy
accesses do seem to be horrifically slow -- even slower than a PC or XT,
and certainly no great shakes above a Mac or Amiga, if at all above.
In fact, and I don't know if this is a fair test -- I once started up a
Mac and my ST running the Magic Sac -- with IDENTICAL disks, and the Mac
finished its startup procedure about 15% faster than the ST!  Considering
that the ST is running at a faster clock rate, its parallel drives are
supposed to transmit much faster than the 512K Mac's drives, etc., etc.,
I found this a bit of a surprise (oh, and the Magic Sac is supposed to
run things "20% faster" than a real Mac).  Ok, so maybe David Small had
to put some unpleasant overhead in there (though frankly judging by the
sounds coming out of the drives, it seems as though it is spending all
its time on accesses, just like the Mac ..);  but still, you would think
with such hardware advantages the ST would either still come out ahead
or at least tie with the 512K Mac ...

Then there's the hard disk;  all the dealers I spoke to insisted the
ST's DMA port was the fastest in the personal computer world -- certainly
Byte insisted it was twice as fast as a Mac+ SCSI;  but the word was that
it was also even faster than an AT's drive.  Why is it, then, that booting
the system with five desk accessories seems to take a million years?  Why
does starting up a program seem to take so long, and MOST importantly,
how can it possibly be that copying files from one directory to another
on the HD seems to take such an amazingly long time?!  If anything,
judging by my experience on XT's, I would be forced to say from copies
that the HD is no faster than an XT HD.  Oops.

Well, these observations are (except for the Mac/Magic test) quite
subjective.  What I am asking for now from the usenet community is any
objective hardware knowledge out there to shed some light on these
things -- is Byte magazine correct in saying the ST is the fastest of
the 68K machines, even in disk-accessing?  What IS the truth about
this?

			thanks much in advance,

									JJMG

P.S.:  I have also heard the opposite about floppy accesses:  one dealer
told me that since the ST uses a Western Digital controller, it has to
store all the pointers in the FATs in Intel format -- low-byte first --
which means the 68000 has to switch them around to read them;  this sounds
fairly ridiculous to me, but has been sounding less so as time has gone
on.


{ seismo | rutgers | decvax!ihnp4 } !husc6!husc4!grunau

dillon@CORY.BERKELEY.EDU.UUCP (01/29/87)

	(Note that the article I'm responding to is included after my responce
so people who are familar with it can abort their text display)

Unfortunetly, relative hardware DMA speeds doesn't really matter when it comes
to disk accesses, just as long as they are in the same ballpark.  You must
also take into account file buffers and the way the DOS optimizes disk space.
A friend of mine has a 20Meg drive (forgot the brand) connected to his Mac's
SCSI port which goes so fast, that it can read a file as fast as the disk
rotates (e.g. one rotation to get a track).  Theoretically, you can't get
any faster than that.

In terms of floppy drives, the original Mac had extremely slow floppies.
The Mac+'s floppy drives are quite fast (quite a bit faster than the Atari's
or the Amiga's).  A 3-1/2 inch floppy spins at 300RPM, and thus you can
theoretically get about 5 tracks a second throughput (Track= a given side,
thus for a double sided drive it would take a rotation to read each side).
The Amiga is about 50% efficient in terms of loading long data files from
floppy (theoretical max @ 11 sectors/track = 28Kbytes/sec, Amiga gets around
15Kbytes/sec).  The test is a simple one... simply start with a blank disk,
write out a very large file, then see how long it takes to read it all in.
(Anybody care to try on an Atari?).  Since your reading large amounts of
contiguous data, this doesn't take into account nominal OS buffering 
optimizations.

The relative slowness of the Amiga's workbench icons popping up is due to 
the fact that the directory structure for an Amiga floppy is optimized for
finding files rather than searching a directory.  C-A made a big mistake
by placing all the icons in separate files, requiring a directory search.
However, this has nothing to do with nominal reading/writing speed for
files.

So, in retrospec, having fast hardware is nice and all, but its advantages
become moot when limited by the physical device (floppy or harddrive) speed.
The floppy drive is going to transfer at 250Kbits/sec no matter how fast
the DMA interface is.

				-Matt

>In fact, they make a fair point of stressing that the ST disk ports are about
>the fastest around.  If you look at the right specs, this seems to be true --
>for instance, Byte lists the top speed of data transmission of the DMA port
>at about twice the top speed of the Mac Plus's SCSI port (I forget the
>figures).  Furthermore, one of the ST articles actually says that most hard
>disks for the 512K Mac transmit at a speed barely above the ST's FLOPPY
>ports, and that (this is the crucial item) the Mac's (serial) floppy ports
>transmit at only a bare fraction of the blindin speed of the ST's (parallel)
>floppy ports.
>
>Now, I should say that this was one of the original pieces of information
>that attracted me to the ST.  I find working with a floppy-based Mac about
>as pleasant as I would imagine having boiling acid dripped into my eyes --
>after a while, the room spins along with the incessant whirring of the
>floppy drives, which seem to take about 75% of your time.  Furthermore,
>my introduction to the Amiga was equally unpleasant -- if anything, judging
>by the speed that a Window displayed its icons, Commodore seemed to have
>achieved the impossible:  floppy accesses even SLOWER than a Mac's.  So
>when Byte happily informed me that the ST's architecture, with its DMA
>chips and its glue chip and its high-speed ports and its 8 MHz clock rate,
>was a speed-machine, I thought "this is the 68K for me!".
>Then there's the hard disk;  all the dealers I spoke to insisted the
>ST's DMA port was the fastest in the personal computer world -- certainly
>Byte insisted it was twice as fast as a Mac+ SCSI;  but the word was that
>it was also even faster than an AT's drive.  Why is it, then, that booting
>the system with five desk accessories seems to take a million years?  Why
>does starting up a program seem to take so long, and MOST importantly,
>how can it possibly be that copying files from one directory to another
>on the HD seems to take such an amazingly long time?!  If anything,
>judging by my experience on XT's, I would be forced to say from copies
>that the HD is no faster than an XT HD.  Oops.
>Well, these observations are (except for the Mac/Magic test) quite
>subjective.  What I am asking for now from the usenet community is any
>objective hardware knowledge out there to shed some light on these
>things -- is Byte magazine correct in saying the ST is the fastest of
>the 68K machines, even in disk-accessing?  What IS the truth about
>this?