20 Sep
2006
20 Sep
'06
3:57 p.m.
Subject: Re: CompuPro floppy controller differences
From: ard at p850ug1.demon.co.uk (Tony Duell)
Date: Wed, 20 Sep 2006 23:16:24 +0100 (BST)
To: cctalk at classiccmp.org
Pft! If you brought them here you'd find spares from used drives or even
working domestic versions. Non of those floppies are exactly rare and even
the SA4000 is still around.
Allison
On Tuesday 19 September 2006 18:57, Tony Duell wrote:
Actually, I've got one that is set to run on 240V, 60Hz. It's out of a
Needless to say the voltage is not that critical. 220V, 230V, 240V are
all the same :-)
I also
have/had a horrible one, originating from a Philips mini (PTS6000)
which used 115VAC for one of the motors
Most [1] 8" droves had mains-operated spindle motors, often 115V
(although 230V versions did exist). Note that the spindle speed depends (broken and now disassembled) IBM 3274 terminal
controller (for the microcode
floppy, of course).
Oh, I'd be happy to change the pulleys and reset the belt tensions. The
problem is _getting_ the pulleys. Do you want to be the chap who phones
Seagate and says 'Hello, I think you used to be Shugart, do you have the
60Hz conversion kits for the SA801, SA851 and SA4000 in stock' [2] One reason I wouldn't conssider moving my
collection to the States.
Oh come on, The Great Dr. Duell isn't afraid of replacing SMT chips on boards,
but is afraid of having to change a few pulleys? Something sounds fishy
here... 
21 Sep
21 Sep
2:28 p.m.
Oh, I'd be
happy to change the pulleys and reset the belt tensions. The
problem is _getting_ the pulleys. Do you want to be the chap who phones
Seagate and says 'Hello, I think you used to be Shugart, do you have the
60Hz conversion kits for the SA801, SA851 and SA4000 in stock'
Pft! If you brought them here you'd find spares from used drives or even
working domestic versions. Non of those floppies are exactly rare and even
the SA4000 is still around. 
3:28 p.m.
On Thursday 21 September 2006 17:28, Tony Duell wrote:
And those were the easy drives. I guess RK05s
wouldn't be too hard to
find 60Hz pulleys for either. What about RX01s/02s? Do RK07s need
converting? RL's I know don't. But my ASR33 would. And all my audio tape
recorders (some of which may never have had 60Hz varients).
It'd probably be easier (and make more sense) to just get a frequency
converter (like maybe a varible frequency motor drive which can output
50Hz)...
Or, if you prefer, a pair of motors with the shafts connected, and the right
RPM ratings, which will do the frequency conversion for you (certainly at a
much less reasonable efficency).
Pat
--
Purdue University ITAP/RCAC --- http://www.rcac.purdue.edu/
The Computer Refuge --- http://computer-refuge.org
4:26 p.m.
[UK disk drives in the States and vice versa]
Or, if you prefer, a pair of motors with the shafts
connected, and the right
RPM ratings, which will do the frequency conversion for you (certainly at a
much less reasonable efficency).
I did suggest getting a motor-generator set in the first message. It might
be easier to link the motor and generator together with the appropiate
mechanical ratio, say by using a toothed belt or gearing, rather than
trying to find units with the right number of poles to be able to link
them directly
-tony
22 Sep
22 Sep
7:24 a.m.
From: Patrick Finnegan <pat at
computer-refuge.org>
On Thursday 21 September 2006 17:28, Tony Duell wrote:
Hi
Although not recommended, years ago we got some 8 inch drive at surplus
that were 50Hz. The drives were cheap and we didn't want to invest a
lot. We simply ground down the motor pulley with a file. We checked our
progress with a strobe disk on the flywheel. It did require elongating the
mounting holes for the motor.
Today, we'd most likely just use a lathe and turn what we needed.
Dwight
And those were the easy drives. I guess RK05s
wouldn't be too hard to
find 60Hz pulleys for either. What about RX01s/02s? Do RK07s need
converting? RL's I know don't. But my ASR33 would. And all my audio tape
recorders (some of which may never have had 60Hz varients).
It'd probably be easier (and make more sense) to just get a frequency
converter (like maybe a varible frequency motor drive which can output
50Hz)...
Or, if you prefer, a pair of motors with the shafts connected, and the
right
RPM ratings, which will do the frequency conversion for you (certainly at a
much less reasonable efficency).
Pat 
9:11 a.m.
On 9/22/2006 at 7:24 AM dwight elvey wrote:
Although not recommended, years ago we got some 8 inch
drive at surplus
that were 50Hz. The drives were cheap and we didn't want to invest a
lot. We simply ground down the motor pulley with a file. We checked our
progress with a strobe disk on the flywheel. It did require elongating the
mounting holes for the motor.
When I wanted to use a 50Hz 8" drive on 60Hz, I worked out the size of the
new pulley, went to Halted and dug around their parts bins. I came up with
something of the right diameter and shaft size, but made for a toothed
timing belt. Not "crowned", but it had flanges to keep the belt in place.
I used it for almost a decade, running the spindle motor from 240v 60Hz,
courtesy of a linear P/S with 2 primary windings hooked in series as an
autotransformer. I didn't have a lathe back then; if I had to do the same
thing today, it'd be a simple matter to turn a new one.
Cheers,
Chuck
9:26 a.m.
New subject: Few Q's about a PET & Expandapet
I have been playing around with the PET and the Expandapet card I
aquired recently.
As there was no documentation with the expandapet, I connected the
floppy cable to the drive and powered first the machine up, and then
the drive.
Floppy lights come on, but the motor does not spin, even for a short
moment.
When I repeat it, but this time reversing the flatcable connector,
the motors do spin constantly.
In both cases, the system reports 8K memory, and the sys(45056) command
freezes the machine completely, only a reset helps.
Oh, the powercable is connected....
On the expandapet board, there are 4 card slots, the last slot (back of
the machine, has the floppy controller, and the slot before that has
the little card with 2 eproms. The remaining 2 slots are empty.
Quetions which comes to mind are
- does the machine report 32K i.s.o 8k when the board is mounted and
connected, or does it always need the SYS command to detect the
extra memory?
- Anyone have the schematics?
Thanks,
Ed
9:33 a.m.
New subject: Few Q's about a PET & Expandapet
- does the machine report 32K i.s.o 8k when the board
is mounted and
connected, or does it always need the SYS command to detect the
extra memory?
It should report all the memory installed, not 8K. You can use the memory
without the SYS command. The SYS command only "hooks in" the disk operating
system commands into the command interpreter - has nothing to do with RAM
usage.
- Bob
23 Sep
23 Sep
10:31 a.m.
From: "Chuck Guzis" <cclist at
sydex.com>
On 9/22/2006 at 7:24 AM dwight elvey wrote:
Hi Chuck
We did similar but used a file to reduce the pully size with the motor
spinning. We also used the input leads of a transformer as an
autotransformer
to reduce the voltage. Using cogged belts for drives can cause
jitter that makes it hard to write and read data. It is true that
most are more forgiving of the motors pulley but I've had cases
where small corrosion on the flywheel surface where the belt
rode was enough to cause problems.
Halted is a local ( Sunnyvale,Ca, USA) surplus shop, for those not
Although not recommended, years ago we got some 8
inch drive at surplus
that were 50Hz. The drives were cheap and we didn't want to invest a
lot. We simply ground down the motor pulley with a file. We checked our
progress with a strobe disk on the flywheel. It did require elongating
the
mounting holes for the motor.
When I wanted to use a 50Hz 8" drive on 60Hz, I worked out the size of the
new pulley, went to Halted and dug around their parts bins. I came up with
something of the right diameter and shaft size, but made for a toothed
timing belt. Not "crowned", but it had flanges to keep the belt in place.
I used it for almost a decade, running the spindle motor from 240v 60Hz,
courtesy of a linear P/S with 2 primary windings hooked in series as an
autotransformer. I didn't have a lathe back then; if I had to do the same
thing today, it'd be a simple matter to turn a new one.
Cheers,
Chuck
from this area.
Dwight
12:13 p.m.
On 9/23/2006 at 10:31 AM dwight elvey wrote:
Halted is a local ( Sunnyvale,Ca, USA) surplus shop,
for those not
from this area.
...and the one-time home of a lot of very strange stuff. Even stranger
than Weird Stuff. Nowadays, it's fairly tame, but it used to be a haunt of
many Silicon Valley engineers.
Cheers,
Chuck
6665
days inactive
6668
days old
9 comments
7 participants
participants (7)
-
ajp166＠bellatlantic.net -
ard＠p850ug1.demon.co.uk -
bob_lafleur＠technologist.com -
cclist＠sydex.com -
dkelvey＠hotmail.com -
pat＠computer-refuge.org -
quapla＠xs4all.nl