BIW109@URIMVS.BITNET (02/28/89)
Over the past weekend I baught the new SpartaDOS X cart. and have
a question about it. It is supposed to support the 1050 drive with
the UD Doubler (among other drives). Naturally, I wanted to see how
much faster the us doubler was (up to now, I have only used the doubler
double density with MYDOS). I formatted a disk with the high speed
sector skew (in SpartaDOS format). I couldn't use the copy command to
move files onto the disk (it doesn't support disk swapping) so I had
to use the menu command (actually I have two drives, but one is at home
on a make-shift computer and the other one is at school on the 'real'
computer). I put a machine language program onto the disk, and it did
seem to write it real (put that in itallics) quick. Great, I thought,
and tried to run it. Well, it loaded and then just sat there (great,
the worlds most advanced paperweight). I thought I must have done
something wrong, because the program runs just fine off of the atari
dos disk. I reformatted the disk, only this time I used the atari
format instead of the Sparta format (but I still used the high speed
sector skew). It worked, but I didn't get the high speed loading...
Also, in both cases the file was shortened when it was copied. I know
it is probably because the file was appended, the only problem is that
when I tried to copy it onto the Sparta format disk, it was shortened
MORE than when I copied it to the atari format disk.(?) I would greatly
appriciate any help on this problem. One of the main reasons I wanted
the cart. is for the high speed data transfer, aside from all of the
goodies in it. Now might be a good time to bring up an old plea, if
anyone has a schematic for the 1200xl (ACK!) I would be willing to trade
some dead presidents for a copy of it....
Many thanks
Raymond Courtois
Bitnet: Biw109@URIMVSgil@limbic.UUCP (Gil Kloepfer Jr.) (03/03/89)
In article <8902280051.AA03433@ucbvax.Berkeley.EDU> BIW109@URIMVS.BITNET writes: >I formatted a disk with the high speed sector skew (in SpartaDOS format). >[...] [The program] seemed to write it real quick, [...] tried to run it. >Well, it loaded and then just sat there [...] Some programs (as you found out) just don't work when used with SpartaDOS. The ones that don't are programs which attempt to call DOS routines directly instead of calling them through Atari's standard I/O mechanism. Granted, their software runs faster, but it is less than DOS-independent. >I reformatted the disk, only this time I used the atari format instead >of the Sparta format (but I still used the high speed sector skew). It >worked, but I didn't get the high speed loading... This is because the high speed I/O is dependent on 2 factors: 1. the disk is written with an optimal sector skew which allows the tracks to be read "faster". Unfortunately, as you may have noticed, some unmodified drives barf on this sector arrangement and will go up to 1/4 as slow as without the skew. 2. When SpartaDOS detects that it has a drive using the US Doubler (see the SpartaDOS manual, SIO calls), it will use its own SIO handler instead of the internal one. For any drives with the US Doubler, when SIO is performed to that drive, it sets the serial line speed according to an index number returned by the US Doubler. Atari DOS loads its own SIO driver (I believe it's for burst I/O), but it has no provision to modify the serial line speed when accessing a drive with a US Doubler. So, unfortunately, when you use the high-speed anything with Atari DOS, you will get less than high-speed results. I did notice, though, that the double density using the US Doubler on a 1050 disk drive is actually FASTER than double density on other disk drives. These observations were made about 5 years ago, so things may have changed now... >One of the main reasons I wanted the cart. is for the high speed data >transfer, aside from all of the goodies in it. Now might be a good >time to bring up an old plea, if anyone has a schematic for the 1200xl (ACK!) >I would be willing to trade some dead presidents for a copy of it.... > Many thanks > Raymond Courtois >Bitnet: Biw109@URIMVS The schematics to the computer won't help you with your quest. What will help are two things: 1. "Inside Atari DOS" (forget the author) which contains the source listing for DOS .. or the DOS that was posted here a while ago. 2. Disassemble the SIO handler for SpartaDOS and examine how the new SIO transfers are performed. You may, then, be able to modify DOS so that it initiates high-speed I/O on US Doubler-modified drives. What's neat about this problem is that it's entirely software-related. You need software to activate the hardware... -------- Gil Kloepfer, Jr. U-Net: {decuac,boulder,talcott,sbcs}!icus!limbic!gil ICUS Software Systems Voice: (516) 968-6860 [H] (516) 746-2350 x219 [W] P.O. Box 1 Internet: gil@icus.islp.ny.us Islip Terrace, NY 11752 "Life's a ... well, you know..."