Re: Micropolis 1525 stuck heads
On 22.09.21 13:46, Jules Richardson via cctalk wrote: On 9/20/21 1:13 AM, Chris Zach via cctalk wrote: Running it through the MFM tool got all but 200 or so sectors on the first pass, most errors were on head 3 but tapered off after cyl 500. Seems like a normal copy of Accent, no special information so it might not be worth taking the world apart to get it working. What's this "MFM tool" of which you speak? Something specific to the PERQ world? I've got various ST506/412-type drives formatted against various controllers in various systems that might benefit from a snapshot. David Gesswein's MFM-reader : https://www.pdp8online.com/mfm/mfm.shtml
Re: Micropolis 1525 stuck heads
On 9/20/21 1:13 AM, Chris Zach via cctalk wrote: Running it through the MFM tool got all but 200 or so sectors on the first pass, most errors were on head 3 but tapered off after cyl 500. Seems like a normal copy of Accent, no special information so it might not be worth taking the world apart to get it working. What's this "MFM tool" of which you speak? Something specific to the PERQ world? I've got various ST506/412-type drives formatted against various controllers in various systems that might benefit from a snapshot. cheers Jules
Re: Micropolis 1525 stuck heads
I have about a dozen or so 1325,1335, and 1355 drives here, also some earlier ones (some have the DEC label) RD50, 51,52, and even a few 54s. If anyone is interested, please contact me off list. Thanks, Paul On Mon, Sep 20, 2021 at 1:14 AM Chris Zach via cctalk wrote: > That is what fixed it, hair dryer blowing around the unit. I stayed away > from the circuit boards and just kept moving to different places. I > thought a head was sticking, but it finally started to move a bit so it > might have been a really gummed bearing. Or #3 head was stuck and > loosened, most of the errors are on that head. > > Running it through the MFM tool got all but 200 or so sectors on the > first pass, most errors were on head 3 but tapered off after cyl 500. > Seems like a normal copy of Accent, no special information so it might > not be worth taking the world apart to get it working. > > Thanks everyone. Back to > > > On 9/20/2021 12:17 AM, Jonathan Stone via cctalk wrote: > > I had suggested a hair-dryer, as recommended circa 20 years ago for > drive "stiction" after disuse. It seems that worked. > > On Sunday, September 19, 2021, 08:58:57 PM PDT, Bill Degnan via > cctalk wrote: > > > > I have simply opened and physically moved the disk counter clockwise a > > turn, in a clean dust-free place. Or try putting in an oven on warm for > 3 > > minutes a side, all four sides to loosen the grease. Might sound crazy > but > > these have worked for me before > > Bill > > > > On Sun, Sep 19, 2021, 10:18 PM Zane Healy via cctalk < > cctalk@classiccmp.org> > > wrote: > > > >> 20+ years ago, I remember people talking about disassembling these to > fix > >> the issue. I’ve never tried. Though I have one or two that might > benefit > >> from is. If the CLASSICCMP archives from ’97-2000 are online, I’d > >> recommend running a search against them. > >> > >> Zane > >> > >> > >> > >> > >>> On Sep 19, 2021, at 3:58 PM, Chris Zach via cctalk < > >> cctalk@classiccmp.org> wrote: > >>> Ok, so out of the basement came a Micrapolis 1325 (the old Dec RD53 > >> disk) with what appears to be stuck heads. Rotor tries to move under > power > >> but can only take out slack. Will move backwards a bit. > >>> Is this stuck head, and what would be the best way to free it? The > >> reason I'm asking is this disk had a SA1000 adapter mounted under it so > I > >> am pretty sure it was a PERQ disk. Which means data may be priceless. > And > >> of course it's stuck. > >>> Thoughts? > >>> > >>> CZ > >>> > >> > > >
Re: Micropolis 1525 stuck heads
That is what fixed it, hair dryer blowing around the unit. I stayed away from the circuit boards and just kept moving to different places. I thought a head was sticking, but it finally started to move a bit so it might have been a really gummed bearing. Or #3 head was stuck and loosened, most of the errors are on that head. Running it through the MFM tool got all but 200 or so sectors on the first pass, most errors were on head 3 but tapered off after cyl 500. Seems like a normal copy of Accent, no special information so it might not be worth taking the world apart to get it working. Thanks everyone. Back to On 9/20/2021 12:17 AM, Jonathan Stone via cctalk wrote: I had suggested a hair-dryer, as recommended circa 20 years ago for drive "stiction" after disuse. It seems that worked. On Sunday, September 19, 2021, 08:58:57 PM PDT, Bill Degnan via cctalk wrote: I have simply opened and physically moved the disk counter clockwise a turn, in a clean dust-free place. Or try putting in an oven on warm for 3 minutes a side, all four sides to loosen the grease. Might sound crazy but these have worked for me before Bill On Sun, Sep 19, 2021, 10:18 PM Zane Healy via cctalk wrote: 20+ years ago, I remember people talking about disassembling these to fix the issue. I’ve never tried. Though I have one or two that might benefit from is. If the CLASSICCMP archives from ’97-2000 are online, I’d recommend running a search against them. Zane On Sep 19, 2021, at 3:58 PM, Chris Zach via cctalk < cctalk@classiccmp.org> wrote: Ok, so out of the basement came a Micrapolis 1325 (the old Dec RD53 disk) with what appears to be stuck heads. Rotor tries to move under power but can only take out slack. Will move backwards a bit. Is this stuck head, and what would be the best way to free it? The reason I'm asking is this disk had a SA1000 adapter mounted under it so I am pretty sure it was a PERQ disk. Which means data may be priceless. And of course it's stuck. Thoughts? CZ
Re: Micropolis 1525 stuck heads
I had suggested a hair-dryer, as recommended circa 20 years ago for drive "stiction" after disuse. It seems that worked. On Sunday, September 19, 2021, 08:58:57 PM PDT, Bill Degnan via cctalk wrote: I have simply opened and physically moved the disk counter clockwise a turn, in a clean dust-free place. Or try putting in an oven on warm for 3 minutes a side, all four sides to loosen the grease. Might sound crazy but these have worked for me before Bill On Sun, Sep 19, 2021, 10:18 PM Zane Healy via cctalk wrote: > 20+ years ago, I remember people talking about disassembling these to fix > the issue. I’ve never tried. Though I have one or two that might benefit > from is. If the CLASSICCMP archives from ’97-2000 are online, I’d > recommend running a search against them. > > Zane > > > > > > On Sep 19, 2021, at 3:58 PM, Chris Zach via cctalk < > cctalk@classiccmp.org> wrote: > > > > Ok, so out of the basement came a Micrapolis 1325 (the old Dec RD53 > disk) with what appears to be stuck heads. Rotor tries to move under power > but can only take out slack. Will move backwards a bit. > > > > Is this stuck head, and what would be the best way to free it? The > reason I'm asking is this disk had a SA1000 adapter mounted under it so I > am pretty sure it was a PERQ disk. Which means data may be priceless. And > of course it's stuck. > > > > Thoughts? > > > > CZ > > > >
Re: Micropolis 1525 stuck heads
I have simply opened and physically moved the disk counter clockwise a turn, in a clean dust-free place. Or try putting in an oven on warm for 3 minutes a side, all four sides to loosen the grease. Might sound crazy but these have worked for me before Bill On Sun, Sep 19, 2021, 10:18 PM Zane Healy via cctalk wrote: > 20+ years ago, I remember people talking about disassembling these to fix > the issue. I’ve never tried. Though I have one or two that might benefit > from is. If the CLASSICCMP archives from ’97-2000 are online, I’d > recommend running a search against them. > > Zane > > > > > > On Sep 19, 2021, at 3:58 PM, Chris Zach via cctalk < > cctalk@classiccmp.org> wrote: > > > > Ok, so out of the basement came a Micrapolis 1325 (the old Dec RD53 > disk) with what appears to be stuck heads. Rotor tries to move under power > but can only take out slack. Will move backwards a bit. > > > > Is this stuck head, and what would be the best way to free it? The > reason I'm asking is this disk had a SA1000 adapter mounted under it so I > am pretty sure it was a PERQ disk. Which means data may be priceless. And > of course it's stuck. > > > > Thoughts? > > > > CZ > > > >
Re: Micropolis 1525 stuck heads
20+ years ago, I remember people talking about disassembling these to fix the issue. I’ve never tried. Though I have one or two that might benefit from is. If the CLASSICCMP archives from ’97-2000 are online, I’d recommend running a search against them. Zane > On Sep 19, 2021, at 3:58 PM, Chris Zach via cctalk > wrote: > > Ok, so out of the basement came a Micrapolis 1325 (the old Dec RD53 disk) > with what appears to be stuck heads. Rotor tries to move under power but can > only take out slack. Will move backwards a bit. > > Is this stuck head, and what would be the best way to free it? The reason I'm > asking is this disk had a SA1000 adapter mounted under it so I am pretty sure > it was a PERQ disk. Which means data may be priceless. And of course it's > stuck. > > Thoughts? > > CZ >
Micropolis 1525 stuck heads
Ok, so out of the basement came a Micrapolis 1325 (the old Dec RD53 disk) with what appears to be stuck heads. Rotor tries to move under power but can only take out slack. Will move backwards a bit. Is this stuck head, and what would be the best way to free it? The reason I'm asking is this disk had a SA1000 adapter mounted under it so I am pretty sure it was a PERQ disk. Which means data may be priceless. And of course it's stuck. Thoughts? CZ
