Ethan's Retrocomputing Corner - PET/CBM disks
cbm-hackers: PET/CBM disks
Date: Mon, 9 Aug 1999 00:31:39 -0400 (EDT)
From: William Levak
To: cbm-hackers@dot.tcm.hut.fi
Subject: CBM Drive Mechanisms
I have been attempting to construct a list of drive mechanisms used by
Commodore (manufacturer and model number). After going through all my
documentation and taking apart all my drives, I was able to produce
the list below. As you can see, there are many question marks in it.
If anyone has the missing information, please fill it in.
2031/2040/3040/4040 Shugart 390
8050 Micropolis 1006-II
Micropolis Safari ?
Tandon ?
MPI 101SM
8250 Micropolis 1006-IV
Micropolis Safari ?
Tandon ?
MPI ?
8250LP ? ?
1001 Matsushita JU-570-2
8280 ? ?
1540/1541/1541A/SX64/2031LP Alps FDM2111-B2
Alps DFB111M25A
1541/1541A Newtronics D500
1541B/1541C(PCB ASSY 250448) Newtronics ?
1541-II ? ?
1570 ? ?
1571 Alps ?
Newtronics D502
C128D Newtronics ?
1581 Chinon F-354E
From: Andre Fachat
Subject: Re: CBM Drive Mechanisms
To: cbm-hackers@dot.tcm.hut.fi
Date: Mon, 9 Aug 1999 09:37:37 +0200 (CEST)
William Levak wrote:
> 8250LP ? ?
The 8250LP in my 8296D has Matsushita drive mechanism. Don't know
the number, though.
Andre
Date: Mon, 09 Aug 1999 14:15:42 +0200
From: Nicolas Welte
To: cbm-hackers@dot.tcm.hut.fi
Subject: Re: CBM Drive Mechanisms
William Levak wrote:
> 1541B/1541C(PCB ASSY 250448) Newtronics D500
but I've heard of many that have an Alps mechanism, so add this line:
Alps ?
> 1541-II Newtronics D500
Chinon ?
Digital System Inc DS-50F
See Ville Jouppi's homepage for this, he has pictures of the mech.
http://www.sci.fi/~vjouppi/digsys.html
> 1570 Alps ?
I didn't know there were two versions of the Alps drive, so I'm not sure
which one was used in the 1570. Anyway it was modified with a track0 and
index sensor.
> 1571 Alps ?
> Newtronics D502
> C128D Newtronics D502
C128DCR Newtronics D502
Nicolas
Date: Mon, 9 Aug 1999 17:59:04 -0400 (EDT)
From: William Levak
To: cbm-hackers@dot.tcm.hut.fi
Subject: Re: CBM Drive Mechanisms
On Mon, 9 Aug 1999, Nicolas Welte wrote:
> William Levak wrote:
> > 1541B/1541C(PCB ASSY 250448) Newtronics D500
> but I've heard of many that have an Alps mechanism, so add this line:
> Alps ?
Commodore documentation says specifically that this version uses a
Newtronics mechanism which is not compatible with the older 1541's.
The 1541 drive series has different system boards that can handle only one
or two drive mechanisms. However, the boards may be put in any case, so
it is necessary identify the PCB ASSY number of the board that the drive
is attached to.
> > 1541-II Newtronics D500
> Chinon ?
> Digital System Inc DS-50F
> See Ville Jouppi's homepage for this, he has pictures of the mech.
> http://www.sci.fi/~vjouppi/digsys.html
I have looked at these pictures. I cannot tell from the pictures if
this is the drive mechanism label. Various parts of drive mechanisms
have labels with serial numbers. I also cannot find a Digital Systems
Inc that makes floppy drives.
The Newtronics D500 may be possible for this drive, but not very likely as
there was a newer version by this time. On the other hand, Commodore
frequently used older parts.
Are these model numbers ones that you have seen yourself? I prefer
first-hand identifications.
Date: Tue, 10 Aug 1999 14:00:16 +0200
From: Nicolas Welte
To: cbm-hackers@dot.tcm.hut.fi
Subject: Re: CBM Drive Mechanisms
William Levak wrote:
> > > 1541B/1541C(PCB ASSY 250448) Newtronics D500
> > but I've heard of many that have an Alps mechanism, so add this line:
> > Alps ?
>
> Commodore documentation says specifically that this version uses a
> Newtronics mechanism which is not compatible with the older 1541's.
> The 1541 drive series has different system boards that can handle only one
> or two drive mechanisms. However, the boards may be put in any case, so
> it is necessary identify the PCB ASSY number of the board that the drive
> is attached to.
The documentation also says that some board versions (I think 250442)
can be configured with a single jumper to be compatible with either the
Alps or Newtronics drive. I don't own an Alps equipped 1541C myself,
both of mine have a track 0 sensor equipped Newtronics drive. But one of
them has the older board installed (250442, IIRC).
> > > 1541-II Newtronics D500
> > Chinon ?
> > Digital System Inc DS-50F
> > See Ville Jouppi's homepage for this, he has pictures of the mech.
> > http://www.sci.fi/~vjouppi/digsys.html
>
> I have looked at these pictures. I cannot tell from the pictures if
> this is the drive mechanism label. Various parts of drive mechanisms
> have labels with serial numbers. I also cannot find a Digital Systems
> Inc that makes floppy drives.
>
> The Newtronics D500 may be possible for this drive, but not very likely as
> there was a newer version by this time. On the other hand, Commodore
> frequently used older parts.
>
> Are these model numbers ones that you have seen yourself? I prefer
> first-hand identifications.
I have both the Newtronics and the Chinon version of the 1541-II, you
have to ask Ville himself about the Digital Systems version. The D500
used in the 1541-II has different plugs than the D500 used in the 1541
and 1541C. Also some D500 that were used in the 1541C were equipped with
the optical track 0 sensor. But all drives were labeled D500, AFAIR. I
will open up the 1541-II again, just to be sure.
Nicolas
Date: Tue, 10 Aug 1999 12:46:16 -0400 (EDT)
From: William Levak
To: cbm-hackers@dot.tcm.hut.fi
Subject: Re: CBM Drive Mechanisms
On Tue, 10 Aug 1999, Nicolas Welte wrote:
> The documentation also says that some board versions (I think 250442)
> can be configured with a single jumper to be compatible with either the
> Alps or Newtronics drive. I don't own an Alps equipped 1541C myself,
> both of mine have a track 0 sensor equipped Newtronics drive. But one of
> them has the older board installed (250442, IIRC).
Board 250442 is the 1541A. This is why it is necessary to check the board
number and not the model number on the case.
> I have both the Newtronics and the Chinon version of the 1541-II, you
> have to ask Ville himself about the Digital Systems version. The D500
> used in the 1541-II has different plugs than the D500 used in the 1541
> and 1541C. Also some D500 that were used in the 1541C were equipped with
> the optical track 0 sensor. But all drives were labeled D500, AFAIR. I
> will open up the 1541-II again, just to be sure.
The D500 on my 1541 says
D500 R69-0001
Perhaps we need to include that extra information with Newtronics drives.
Could you also look for the model number on the Chinon? Their labels are
usually on the side of the drive and easy to access.
Bill
Date: Tue, 10 Aug 1999 22:23:33 +0200
From: Nicolas Welte
To: cbm-hackers@dot.tcm.hut.fi
Subject: Re: CBM Drive Mechanisms
William Levak wrote:
> The D500 on my 1541 says
>
> D500 R69-0001
>
> Perhaps we need to include that extra information with Newtronics drives.
The one in my 1541-II simply says "D500 S/N70100511". The connectors are
6pin for the stepper, 3 pin for the spindle motor and 4 pin for the WP
sensor. The latter two mount onto the 7 pin header CN4.
The one in my 1541C with 1541A board says: "D500 S/N70150371". It is
equipped with the track 0 sensor and therefore the 15 pin plug carries 9
cables instead of the usual 6 ones. Otherwise it is very similar to the
1541-II one.
I don't want to open up my 1541 with Newtronics drive and 1541A board,
but that one has the upper WP sensor mounted on a plastic mount that
extends from the front bezel. The above mentioned 1541C and 1541-II
drives use a little PCB that is installed to the drive mech itself. So
there are many variants of the D500 drive, but I don't see how to
distinguish them just by the model number or the label information.
> Could you also look for the model number on the Chinon? Their labels are
> usually on the side of the drive and easy to access.
The label on the back says: "Model FZ-501M REV A", "Serial No.
10216572". The connectors are 6 pin for the stepper and 5 pin for the
spindle motor and WP sensor. This leaves pin 1 and 2 of CN4 empty, they
aren't even installed in this drive.
Nicolas
Date: Wed, 11 Aug 1999 02:32:31 -0400 (EDT)
From: William Levak
To: cbm-hackers@dot.tcm.hut.fi
Subject: Re: CBM Drive Mechanisms
Nicholas
I took my 1541A completely apart and traced the lines on CN6. The results
are in the first column below.
1451A 1541B/C 1541-II
WP LED
1 GND 1 GND 1 GND
2 150 OHM to 5V 2 150 OHM to 5V 2 150 OHM to 5V
MOTOR LED
8 5V 6 5V 6 12V
9 MTR 9 MTR 7 MTR
WP SENSOR
12 WP 12 WP 3 WP
13 GND 13 GND 4 GND
4 150 OHM to 5V
5 GND 5 GND
8 150 OHM to 5V
The other two columns are derived from the lines on the circuit board
schematics and are guesses as to what lines are on the connectors. The
connectors may not actually have lines in all positions.
No connection on pins 1 and 2 would indicate a mechanical WP switch
instead of a LED-photocell combination.
The fact that your 1541C has 9 lines on the connector indicates that it
may actually be a 1541C drive and only the circuit board has been changed.
It may be helpful to know if all these lines are actually on the
connectors and what the extra 3 lines on the 1541C are connected to.
On examining the photos in the SAMS PHOTOFACT folder for the 1541 drive, I
can see that the Model number of that drive mechanism says D500 R69-0001,
just as mine does. It appears therefore that the Newtronics drive
mechanism for the 1541/1541A is D500 R69-0001 and the latter drives are
D500s.
You also mentioned that some of the drives had "AFAIR" on them. I don't
quite understand which ons that referres to.
Bill
Date: Wed, 11 Aug 1999 11:00:53 +0200
From: Nicolas Welte
To: cbm-hackers@dot.tcm.hut.fi
Subject: Re: CBM Drive Mechanisms
William Levak wrote:
> No connection on pins 1 and 2 would indicate a mechanical WP switch
> instead of a LED-photocell combination.
It's somewhat different. For the Chinon drive the WP LED is mounted on
the direct drive spindle motor PCB and gets its power from there. So the
supply from pins 1 and 2 of CN4 is not needed.
The term "MOTOR LED" is not quite correct. In the case of the 1541A and
B/C, it is the "ACTIVE LED". The spindle motor is controlled by an extra
three pin connector on these drives. In the 1541-II, the active and
power LEDs are connected directly via cables to the main PCB, there is
no connector. Pins 5,6,7 on CN4 go to the spindle motor control PCB.
In my 1541A/C drive (the one with the white case but 250442 board) pins
4,5,6 of CN6 are connected to the track 0 sensor. This is an integrated
light barrier with LED and sensor in one case. One is GND, one is the
LED supply and the other one is the sensor input. On most 250448 this is
tied to GND with a jumper, to make the use of sensor-less drives
possible.
> The fact that your 1541C has 9 lines on the connector indicates that it
> may actually be a 1541C drive and only the circuit board has been changed.
I can't be sure of that, I got it second hand. But since the original
owner had a parallel cable installed and also told me that he fried the
VIA while installing it, I don't think he ever had it in a repair shop
to get the complete board replaced.
Nicolas
Date: Wed, 11 Aug 1999 20:41:52 +0200
From: Frank Kontros
Organization: Home HQ
To: Nicolas Welte
Subject: Re: CBM Drive Mechanisms
Hello,
>> 1541-II Newtronics D500
Nicolas> Chinon ?
Nicolas> Digital System Inc DS-50F
I've something else:
1541-II On the Mech. label: Safronic Corp. DS-50F Made in Japan
Nicolas> See Ville Jouppi's homepage for this, he has pictures of the mech.
Nicolas> http://www.sci.fi/~vjouppi/digsys.html
The drive mechanism on pictures is same that I've.
Best regards,
Frank
Date: Wed, 11 Aug 1999 14:51:57 -0400 (EDT)
From: William Levak
To: cbm-hackers@dot.tcm.hut.fi
Subject: Re: CBM Drive Mechanisms
I think this is beginning to make sense.
1451A CN6 1541B/C CN3 1541-II CN4
------------------ --------------- ----------------
WP LED POWER(optional)
1 GND 1 GND 1 GND
2 150 OHM to 5V 2 150 OHM to 5V 2 150 OHM to 5V
MOTOR ACTIVITY LED
8 5V 6 5V 6 12V
9 MTR 9 MTR 7 MTR
WP SENSOR
12 WP 12 WP 3 WP
13 GND 13 GND 4 GND
TRACK 0 SENSOR POWER
4 150 OHM to 5V
5 GND
8 150 OHM to 5V
Probably Not Used
5 GND
For the benefit of those who do not have a 1541 drive to look at:
There is a small circuit board mounted on the Newtronics drive mechanism.
The stepper motor is connected to the Commodore system board through this
circuit board.
On my 1541 Newtronics drive, there is a mounting for a track 0 sensor and
there is a tab on the head assembly that would trigger the sensor if it
were there.
Nicholas reports that on his 1541C drive there is a track 0 sensor that
gets it's power from the Commodore system board, but connects the output
signal to the stepper motor board.
This makes sense because none of the 1541 ROMs and none of the Commodore
system boards provide support for a track 0 signal. If the track 0 signal
is connected to the stepper motor board, then it can turn off the stepper
motor at track zero without any active support from the Commodore System.
It only needs a power supply, which the 250442 (1541A) and 250446 (1541A2)
system boards supply. On the other 1541s, just removeing the track 0 sensor
and disconnecting it from the stepper moter board should convert it to a
drive without track 0 sensing.
To summarize:
1541/1541A drive without track 0 sensor and CN6 connector
1541B/1541C drive with track 0 sensor and CN3 connector
1541-II drive without track 0 sensor and CN4 connector
It appears then that the same Newtronics D500 drive mechanism is used on
all 1541 drives, only with different connectors and the track 0 sensor
removed on some.
This would also mean that the drive mechanisms should be compatible
across all the 1541s if you change the connector.
Date: Wed, 11 Aug 1999 22:57:07 +0200
From: Nicolas Welte
To: cbm-hackers@dot.tcm.hut.fi
Subject: Re: CBM Drive Mechanisms
William Levak wrote:
> The stepper motor is connected to the Commodore system board through this
> circuit board.
No, Bill, it's the spindle motor. The stepper motor is always connected
directly to the drive's main board.
> Nicholas reports that on his 1541C drive there is a track 0 sensor that
> gets it's power from the Commodore system board, but connects the output
> signal to the stepper motor board.
I didn't say this. I said that the WP LED is connected to the spindle
motor control PCB, and it was on the Chinon drive.
> This makes sense because none of the 1541 ROMs and none of the Commodore
> system boards provide support for a track 0 signal.
250448 has an input for the track 0 sensor, it's mostly disabled by a
short to GND (It was via J3, I think), but otherwise connected to PA0 of
the bus VIA. The ROMs 251968-01 and 251968-02 have support for this
signal. The 1541-II has the GND connection to PA0 left to enable this
board to work with the two above mentioned ROMs. But the drive was only
shipped with 251968-03 which had the sensor support removed.
> If the track 0 signal
> is connected to the stepper motor board, then it can turn off the stepper
> motor at track zero without any active support from the Commodore System.
I'd really love to see this solution in any Commodore drive. But I never
did. BTW, my SFD1001 also has a track 0 sensor, but doesn't make use of
it. Neither in hardware or software.
> It appears then that the same Newtronics D500 drive mechanism is used on
> all 1541 drives, only with different connectors and the track 0 sensor
> removed on some.
I agree with you here, but the sensor probably doesn't have to be
removed. Like on my 250442 board, where there's simply nothing useful
connected to the track 0 sensor pins.
> This would also mean that the drive mechanisms should be compatible
> across all the 1541s if you change the connector.
This is true.
Nicolas
Date: Wed, 11 Aug 1999 19:36:06 -0400 (EDT)
From: William Levak
To: cbm-hackers@dot.tcm.hut.fi
Subject: Re: CBM Drive Mechanisms
On Wed, 11 Aug 1999, Nicolas Welte wrote:
> No, Bill, it's the spindle motor. The stepper motor is always connected
> directly to the drive's main board.
I checked again. You're right
> I didn't say this. I said that the WP LED is connected to the spindle
> motor control PCB, and it was on the Chinon drive.
OK, but this causes further problems.
> 250448 has an input for the track 0 sensor, it's mostly disabled by a
> short to GND (It was via J3, I think), but otherwise connected to PA0 of
> the bus VIA. The ROMs 251968-01 and 251968-02 have support for this
> signal. The 1541-II has the GND connection to PA0 left to enable this
> board to work with the two above mentioned ROMs. But the drive was only
> shipped with 251968-03 which had the sensor support removed.
It's 250442 and 250446 (1541A) that have the input and it is jumpered out
by J3 and it was shipped with the drive without the sensor.
250448 (1541B) has the power for the track 0 sensor, but where does the
output signal go??
> > It appears then that the same Newtronics D500 drive mechanism is used on
> > all 1541 drives, only with different connectors and the track 0 sensor
> > removed on some.
>
> I agree with you here, but the sensor probably doesn't have to be
> removed. Like on my 250442 board, where there's simply nothing useful
> connected to the track 0 sensor pins.
So why connect power to the sensor (on the 1541B) if the output goes
nowhere??
Date: Wed, 11 Aug 1999 19:58:13 -0400 (EDT)
From: William Levak
To: Nicolas Welte
Subject: Re: CBM Drive Mechanisms
On Wed, 11 Aug 1999, Frank Kontros wrote:
> Hello,
>
> >> 1541-II Newtronics D500
> Nicolas> Chinon ?
> Nicolas> Digital System Inc DS-50F
>
> I've something else:
>
> 1541-II On the Mech. label: Safronic Corp. DS-50F Made in
Japan
> Nicolas> See Ville Jouppi's homepage for this, he has pictures of the mech.
> Nicolas> http://www.sci.fi/~vjouppi/digsys.html
>
The Digital System drive is made in Japan also. Those model numbers are
suspiciously alike. It's probably the same drive with a different label.
Ville Jouppi confirms that it is the mechanism label located on the drive
body.
Bill
Date: Thu, 12 Aug 1999 13:21:20 +0200
From: Nicolas Welte
To: cbm-hackers@dot.tcm.hut.fi
Subject: Re: CBM Drive Mechanisms
William Levak wrote:
> > I didn't say this. I said that the WP LED is connected to the spindle
> > motor control PCB, and it was on the Chinon drive.
>
> OK, but this causes further problems.
Why? Pins 1 and 2 are just the power supply of the WP LED, what problems
arise if the power is supplied through the spindle motor PCB?
> It's 250442 and 250446 (1541A) that have the input and it is jumpered out
> by J3 and it was shipped with the drive without the sensor.
Aha, I had a look at the schematic for those drives and you probably
mean the input at pin 14 of CN6 or P6. You're right, this input is
somewhat connected to an optional circuit, but this is not related to a
track 0 sensor. As I understand that circuit, it will activate the
spindle motor for some seconds each time it is triggered by a disk
change signal. This disk change signal can either be generated by the
write protect sensor (J3 closed) or by an extra disk change sensor at
pin 14 of CN6 (J4 closed), but I've never seen a drive with that extra
sensor or the optional circuit.
The functionality of this circuit has been delivered by software in the
later 1541C drives, if they were equipped with the 1541B board and the
proper firmware.
> 250448 (1541B) has the power for the track 0 sensor, but where does the
> output signal go??
Pin 6 of connector P5 carries the TR0 input to the PA0 input of VIA UC1,
via two inverters of UC6. The signal can be disabled by J3, which
enables a permanent connection to GND.
The 1541-II board has a permanent connection to GND at PA0, while
earlier drives have this pin not connected.
> So why connect power to the sensor (on the 1541B) if the output goes
> nowhere??
It does go somewhere, it's visible in the schematics. And it works, a
real 1541B/C drive with J3 open makes use of the sensor and doesn't
rattle the head on a disk format or error anymore.
Nicolas
Date: Thu, 12 Aug 1999 15:19:57 -0400 (EDT)
From: William Levak
To: cbm-hackers@dot.tcm.hut.fi
Subject: Re: CBM Drive Mechanisms
On Thu, 12 Aug 1999, Nicolas Welte wrote:
> Aha, I had a look at the schematic for those drives and you probably
> mean the input at pin 14 of CN6 or P6. You're right, this input is
> somewhat connected to an optional circuit, but this is not related to a
> track 0 sensor. As I understand that circuit, it will activate the
> spindle motor for some seconds each time it is triggered by a disk
> change signal. This disk change signal can either be generated by the
> write protect sensor (J3 closed) or by an extra disk change sensor at
> pin 14 of CN6 (J4 closed), but I've never seen a drive with that extra
> sensor or the optional circuit.
Not to mention that J4 is open so that it won't work anyway.
> Pin 6 of connector P5 carries the TR0 input to the PA0 input of VIA UC1,
> via two inverters of UC6. The signal can be disabled by J3, which
> enables a permanent connection to GND.
> It does go somewhere, it's visible in the schematics. And it works, a
> real 1541B/C drive with J3 open makes use of the sensor and doesn't
> rattle the head on a disk format or error anymore.
I missed that circuit.
So, the 1541B/1541C can use a drive with track 0 sensor.
But this does not make the drive electrically incompatible as Commodore
claimed. If your drive doesn't have a track 0 sensor, you just close J3.
If you use a drive with a track 0 sensor on a board that doesn' support
it, it doesn't matter as it isn't connected to anything.
Date: Sun, 15 Aug 1999 00:43:53 -0400 (EDT)
From: William Levak
To: cbm-hackers@dot.tcm.hut.fi
Subject: Re: CBM Drive Mechanisms
> From SAMS Computerfacts for the 1571
DRIVE MOTOR NOT WORKING
(A) Check connector CN7 for good connections.
(B) Check for 12V at pin 2 of Connector CN7, if 12V is missing check power
supply.
(C) if 12V is present, connect a jumper from pin 3 of CN7 to ground. The
should start running. If motor does not start running, check Motor
Control Board. If motor does start running, check the main board.
In addition you should clean off all corrosion, and clean off any dirt on
the circuit boards and drive mechanism with isopropyl alcohol. Check that
the spindle motor spins freely with the power off.
On Sat, 14 Aug 1999, Geoff Oltmans wrote:
> Since we're on the subject of drive mechs, let me throw this problem on
> the list...
>
> I've got a sick 1571 mech. It's a newtronics mech, and SOMETIMES (not all
> the times) the spindle motor won't start up... on top of that, reading is
> very sporadic (probably I feel due to slightly varying spindle motor
> speeds). Anyone experience this problem before and know a fix for it?
>
> One thing I've noticed: This mech actually came out of a 128DCR. Around
> the floppy bay there is noticeable corrosion on the case. It's not
> horrible, but the floppy mech has some corrosion/rust on the metal bits. I
> suppose it could be that the electrolytic caps on the spindle motor board
> are contaminated or something.
>
> Later,
>
> *Geoff!*
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