[comp.sys.atari.st] Having problems with my Spectre GCR

pavneet@klg.UUCP ( KL Group Inc.) (02/05/91)

Hi,

Ever since I purchased my Spectre cartridge last year, I have had problems
with it reading Mac floppies.  I have run gcrtest a number of times and
I get different read/write failures each time.  Has anyone else had these
types of problems?  (I had sent the cartridge back to GBS to let them
have a look at it.  They returned it saying that it tested fine on their
machine, which is probably true, but doesn't help me any.)

I haven't had any problems with my floppy drive in any other way, but I guess
that Spectre stresses the floppy a little more.

I'd be grateful for suggestions/opinions.

advTHANKSance

Pavneet Arora

e-mail:  ...!utzoo!rom!pavneet   <-- This is different from my news account.

hojo@cbnewsb.cb.att.com (HC Johnson) (02/05/91)

In article <123@klg.UUCP>, pavneet@klg.UUCP ( KL Group Inc.) writes:
> Hi,
> 
> Ever since I purchased my Spectre cartridge last year, I have had problems
> with it reading Mac floppies.  I have run gcrtest a number of times and
> I get different read/write failures each time.  Has anyone else had these

Just a reminder that not all 720K drives used on Atari's will work with 
Spectre GCR (or Translator one).  The effect of MAC encoding is to cause the
Atari to write on the floppy as if it were a 1.44 meg drive.  

Some 720K drives don't work this way because they have a filter to improve
the signal and won't pass 1.44 meg frequencies.  Others don't have the
full bandwidth in their signal path (heads/electronics).

What to do?

1. replace your built-in drive with one known to work with Spectre.
2. Buy a SF314 that you can TEST first with Spectre.
3. Buy a cheap MAC.  The original Magic-SAC had a program to copy discs 
	from a MAC to the Atari.

Howard Johnson
ATT BELL LABS
att!lzsc!hcj
hcj@lzsc.att.com

mjv@brownvm.brown.edu (Marshall Vale) (02/07/91)

In article <123@klg.UUCP> pavneet@klg.UUCP ( KL Group Inc.) writes:
> Ever since I purchased my Spectre cartridge last year, I have had 
problems
> with it reading Mac floppies.  I have run gcrtest a number of times and
> I get different read/write failures each time.  Has anyone else had these
> types of problems?  (I had sent the cartridge back to GBS to let them


 Howard Johnson posted a very good explanation about the problems and I'm
going to add some more ideas.
 
 One thing to check is if your drive is a NEC mechanism. Those have 
known problems reading GCR disks and require a hardware modification
to work properly. If it is a NEC drive, contact GBS for the fix info.

 You also didn't mention whether you are having the problems with an
internal drive (especially a Mega internal). If it is an internal drive
you should try adding extra shielding around the drive and its cables
and then ground the shielding to the motherboard. The ST generates lots
of RF and on some machines (Mega2's particularly) it just drones the
Mac signal out. Although this mod never worked for my Mega2, I know
lots of cases where it has cured the problem. 

 Another idea is move the monitor farther away and even a different angle.
When moving my system around, I placed the monitor on the floor to make
some temp room. This caused my rock solid external drive to stop reading
mac disks. Moving the monitor back to its old spot (which was in fact
closer to the drive but had a shelf between them) cured the problem.

 Also check your drive speed is 300rpm.

 Hope these suggestions help!

Marshall Vale

 *******************************************************************
-> Internet: mjv@brownvm.brown.edu
"He had found the perfect TV mix, on Marvin's Hour of Power.
 (The show that put the FUN back into fundamentalist)."
   -- Neil Gaiman; Good Omens: The Nice and Accurate Prophecies of 
     Agnes Nutter, Witch

sytang@lamar.ColoState.EDU (Shoou-yu tang) (02/07/91)

In article <123@klg.UUCP> pavneet@klg.UUCP ( KL Group Inc.) writes:
>Ever since I purchased my Spectre cartridge last year, I have had problems
>with it reading Mac floppies.  I have run gcrtest a number of times and
( stuffs deleted)
>e-mail:  ...!utzoo!rom!pavneet   <-- This is different from my news account.

 Which version of Spectre? the GCR test come with version 2.3 ( the one before
2.6) has problem with single drive setup. And some system is very sensitive to
the E_M interference generated by the monitor. My old 1040 ST was one of them,
try to move the monitor away from the cable and drive then try again. Also put
a sheild on the drive cable help.

 Tang
 sytang@lamar.colostate.edu

bri@jake.tmc.edu (Brian Holmes) (02/08/91)

In article <123@klg.UUCP> pavneet@klg.UUCP ( KL Group Inc.) writes:
>
>I haven't had any problems with my floppy drive in any other way, but I guess
>that Spectre stresses the floppy a little more.
>
NEC drives, which INDUS uses, need to have a resister soldered in.
This was mentioned in one of the newsletters.  Call Gadgets, as
they have a little sheet explaining what to do.

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