I missed it when I was making the video but the name of the control board is there, it says "power computing high density floppy" on the PCB. And a quick google of that shows someone had one here www.amibay.com/threads/power-computing-xl-amiga-external-1-76mb-high-density-floppy-drive.2441788/ This "high density" thing probably also explains why the control board is so complex (that high pin count chip in the middle) as this drive is designed to be able to read and write much higher density disks that was normal during the Amiga's life time.
Get some contact cleaner into the switch (I saw you did that) on the back and try it in both positions again - beyond that I would look at that 1 x 74 series soldered onto the board. Reseat the PLCC chip - take it out and put it back in. The GAL may have died though, or the PLCC chip. Happy New Year btw =D
Potentially, maybe just maybe, the contents of the programmable chip can br hashed for its checksum via something like the TL866II_Plus_USB such that investigating on various sites might lead to the same checksum being _"almost unique enough"_ to show what it is _(by means of what is in it, or at least the result of the signal applied to what is in it),_ whether or not a backup of its contents are also accomplished in similar ways with gadgets. The other benefit is that, upon solving the problem, anybody else who likewise, in future, uses the checksum to get info at sites matching it can thereby be helped. Rainbow-tables of checksums like that could be used to narrow down what makes a device tick whether or not it too has its FCC_ID which is of course also handy, if a device even has one. A gander on the Amiga hardware database could also be a far shot but a shot nonetheless. Technically, a signal path of a known quantity generated function _(perhaps polynomial)_ sent through the programmable chip from a signal generator (function generator) to be read by logic analyser could reverse engineer, by discovery, the logic gates within it. A lookup_table with checksums, yet again, in accordance with that, could help solve problems and help other people in future trying to fathom what is up with such a device, or with other devices using a Phase-Locked-Loop perhaps with FPGA as a way to read it. Checking for a dead GAL could be done via something of the aforementioned routes.
Maybe it was just made very late in the Amiga's life span, but they used an old stock of drives. I hadn't considered getting a modern replacement board for the electronics and stuffing it in the enclosure.
The metallic bags have a very thin conductive layer sandwiched between two plastic layers that act like a faraday cage. If two chip legs puncture the outer plastic layer you could get a short circuit it seems.
@@retronoby Just got home, I checked a bag and the conductivity (inside, outside and spiked), is poor (Mohms) . Enough to disperse static e but not enough to be classed as a common conductor. I'm surprised at this result. I assumed all my life that these coated mylar bags were conductive. Can someone else test to see if this is normal?
@@Vanders456 I know it's crazy. Seems like everyone today is using GoTek or other drive emulators (or WHDLoad), yet the price of even a broken drive is getting really high. I saw some going for quite high prices at auction, so it's not just sellers that are to blame.
I missed it when I was making the video but the name of the control board is there, it says "power computing high density floppy" on the PCB. And a quick google of that shows someone had one here www.amibay.com/threads/power-computing-xl-amiga-external-1-76mb-high-density-floppy-drive.2441788/
This "high density" thing probably also explains why the control board is so complex (that high pin count chip in the middle) as this drive is designed to be able to read and write much higher density disks that was normal during the Amiga's life time.
Get some contact cleaner into the switch (I saw you did that) on the back and try it in both positions again - beyond that I would look at that 1 x 74 series soldered onto the board. Reseat the PLCC chip - take it out and put it back in. The GAL may have died though, or the PLCC chip. Happy New Year btw =D
@@GadgetUK164 Happy new year! Thanks for the tips. Off camera I did try both switch positions, but no joy.
Very interesting problem 🤔
Potentially, maybe just maybe, the contents of the programmable chip can br hashed for its checksum via something like the TL866II_Plus_USB such that investigating on various sites might lead to the same checksum being _"almost unique enough"_ to show what it is _(by means of what is in it, or at least the result of the signal applied to what is in it),_ whether or not a backup of its contents are also accomplished in similar ways with gadgets. The other benefit is that, upon solving the problem, anybody else who likewise, in future, uses the checksum to get info at sites matching it can thereby be helped. Rainbow-tables of checksums like that could be used to narrow down what makes a device tick whether or not it too has its FCC_ID which is of course also handy, if a device even has one. A gander on the Amiga hardware database could also be a far shot but a shot nonetheless.
Technically, a signal path of a known quantity generated function _(perhaps polynomial)_ sent through the programmable chip from a signal generator (function generator) to be read by logic analyser could reverse engineer, by discovery, the logic gates within it. A lookup_table with checksums, yet again, in accordance with that, could help solve problems and help other people in future trying to fathom what is up with such a device, or with other devices using a Phase-Locked-Loop perhaps with FPGA as a way to read it. Checking for a dead GAL could be done via something of the aforementioned routes.
That looks like a modern board in a classic case, well more modern than original hardware. PCB way do an external amiga board
Maybe it was just made very late in the Amiga's life span, but they used an old stock of drives. I hadn't considered getting a modern replacement board for the electronics and stuffing it in the enclosure.
I took another look at the board, see my pinned comment.
@@DavePoo2 i had that PowerComputing drive back on my original 1200. HD was useful 1.7mb.
It could even be the cable that connects the drive to the Amiga?
@@paszTube it's possible but seems the least likely problem as the cable looks very sturdy and has no signs of damage.
Do you have a eprom burner? You can pull out the gal and read it in a eprom burner and see if its ok.
@@TheMcflyster I do
HNY Dave. Could the GAL have lost it's firmware or gotten corrupted?
Maybe, I've seen them go bad before (when I was making one the GAL PLA for the C64)
[Personal Prissy Moment]... 2:28 ... What? Protecting a circuit board from shorting out using an electrically conductive bag? [And Relax]
@@marjon1703 it doesn't conduct (I checked it). It probably does conduct, but not enough for my meter to measure.
th-cam.com/users/shortsBAFi63JhVr4 - Here is what got edited out of the video
The metallic bags have a very thin conductive layer sandwiched between two plastic layers that act like a faraday cage. If two chip legs puncture the outer plastic layer you could get a short circuit it seems.
@@retronoby Look out for a follow up video.
@@retronoby Just got home, I checked a bag and the conductivity (inside, outside and spiked), is poor (Mohms) . Enough to disperse static e but not enough to be classed as a common conductor. I'm surprised at this result. I assumed all my life that these coated mylar bags were conductive. Can someone else test to see if this is normal?
There is no data, only Zool.
Very good!
Sellers asking thee figures for a 3rd party external floppy drive will never not make me laugh.
@@Vanders456 I know it's crazy. Seems like everyone today is using GoTek or other drive emulators (or WHDLoad), yet the price of even a broken drive is getting really high. I saw some going for quite high prices at auction, so it's not just sellers that are to blame.