Well, I don't seem to be making any progress.
I've tried to flush under the 82C711 with vinegar and water to try to neutralise any gunk under there.
I've reworked the repairs I did to broken traces just to make sure they're good.
All to no avail. Indeed things seem to have got worse as I can't get the Floppy Drive recognised at all now and if there is any activity it is movement of the head towards the spindle. Sometimes it even has a fit with the head rattling around.
I'm still confused by the datasheet which seems ambiguous.
It says that TRK0 is active low (which I'm reading as it goes low when you get to track 0)
And DIR low means step in (towards the spindle?) and high means step out.
All well and good but the Recalibrate command, which I'm assuming happens at startup, says
It all seems like the 82C711 isn't awake. I've checked PWRGD as if this is low the chip is inactive, but its fine.
Although all of the connections seem to have continuity I have noticed that the corrosion on some may have narrowed the trace (after scraping away the corrupted solder resist. Could this affect the operation? Is it worth running some solder along the damaged areas just in case?
I've tried to flush under the 82C711 with vinegar and water to try to neutralise any gunk under there.
I've reworked the repairs I did to broken traces just to make sure they're good.
All to no avail. Indeed things seem to have got worse as I can't get the Floppy Drive recognised at all now and if there is any activity it is movement of the head towards the spindle. Sometimes it even has a fit with the head rattling around.
I'm still confused by the datasheet which seems ambiguous.
It says that TRK0 is active low (which I'm reading as it goes low when you get to track 0)
And DIR low means step in (towards the spindle?) and high means step out.
All well and good but the Recalibrate command, which I'm assuming happens at startup, says
Which implies that TRK0 goes high when it reaches track 0 and the direction of movement is towards the spindle which seems to be wrong. Anyone able to explain this for me?As long as the Track 0 signal is low, the Direction signal remains 0 (low) and Step Pulses are issued. When the Track 0 signal goes high, the SE (SEEKEND) flag in Status Register 0 is set to a 1 (high) and the command is terminated
It all seems like the 82C711 isn't awake. I've checked PWRGD as if this is low the chip is inactive, but its fine.
Although all of the connections seem to have continuity I have noticed that the corrosion on some may have narrowed the trace (after scraping away the corrupted solder resist. Could this affect the operation? Is it worth running some solder along the damaged areas just in case?
Statistics: Posted by rodders — Wed Feb 28, 2024 11:43 am