On 2/12/25 14:27, Francesco Messineo wrote: > On Wed, Feb 12, 2025 at 2:17 PM <groepaz_at_gmx.net> wrote: >> >> Am Mittwoch, 12. Februar 2025, 14:03:34 Mitteleuropäische Normalzeit schrieb >> Francesco Messineo: >>> Hi all, >>> I've just recapped a Panasonic JU-570-2 with horribly leaking >>> capacitors that ate a few traces on the spindle PCB. Now before >>> assembling back the SDF-1001 I wanted to test and correct the spindle >>> speed if needed. However the drive motor doesn't have the strobo >>> patterns, so an alternate method must be used. Does anyone know if any >>> of the programs on the test/demo disks can help? Images as many of you >>> know are here: >>> https://www.zimmers.net/anonftp/pub/cbm/demodisks/drives/index.html >>> Does anyone know any test point on the spindle PCB? I think pin 6 of >>> the motor controller IC could be a good place to look, but I figured >>> out someone must already know how to do this task. >>> Thanks in advance. >>> Frank IZ8DWF >> >> Perhaps you can adapt one of these programs to the sfd: >> >> https://sourceforge.net/p/vice-emu/code/HEAD/tree/testprogs/drive/rpm/ > > thanks, those could be a good starting point indeed :) > I think the only one that could be suitable is rpm3 (with or without > changing the target track formatted) since the other two need properly > formatted disks that I don't have (yet). > > However (full disclosure), the JU-570 mechanics has the index sensor > and the control board isn't using it, so I can add a little resistor > to Vcc to read the pulses (phototransistor wires are coming to P1 > connector) and use a time interval counter (200 ms is the nominal > pulse interval). I was just hoping there was a faster way. You could make a photo of the strobo pattern from a 1541, print it and glue it onto the spindle of the SFD-1001. Assuming the SFD-1001 also uses 300 rpm, that should work. GerritReceived on 2025-02-12 15:00:39
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