My Emax HD keyboard has bit the dust.
Specifically, the hard drive is shot and probably the floppy too.
But everything else should be salvageable.
Would like to donate its vital organs to worthy Emax owners striving to keep their beasts alive.
Don’t want money beyond shipping costs.
Prefer to keep entire boards intact rather than taking off individual chips.
Here’s hoping we can keep the bulk of this beautiful creature out of the landfill.
Did anyone take you up on your offer?
Not yet. I decided to not be such a wimp and try to actually fix this thing. It boots and displays an error message (via LEDs) that indicates there was a disk failure. I know the hard drive is shot but it should still boot from floppy. But it appears shot too. Am currently trying to replace with $10 floppy drives from eBay. No luck so far but another one is coming in this week…
A standard floppy drive will not work because most are hard set to a ID of 1 instead of ID 0. With that said, Depending on your skill set, the original drive might just need a head cleaning and or belt replacement.
If you change your mind, I could use the parts. Let me know.
That’s a good theory, but I don’t think that’s quite it. The Emax was never designed to support two floppy drives: it ties both Motor pins together and leaves the ID pins floating. That way no matter how the drive is wired it will see a motor signal.
The drive spindle motor does come on and the platter spins. The Emax writes a RESTORE command (0x0B) to the WD1772 controller which then waits for 6 Index pulses to occur. The drive never sends these index pulses even though the platter continues to spin. The result is a hang.
The mystery continues…
…10 minutes later:
No, wait! You’re absolutely correct! Thank you!
The pin 12 Drive Select was left floating so it was high (inactive). All I needed to do was ground it (active low). Now the Emax is booting from floppy, loads a bank!
Now I have to put it all back together and see if it makes sound…
…Success! The Emax is now functional.
For posterity: anyone looking to make a “new” floppy drive work with an E-mu Emax: connect pin 12 of the 34-pin floppy connector to ground, which is conveniently located next door at pin 13. I made my mod on the underside of the Emax digital board.
Thank you @blackelk001 for pointing me in the right direction.
Now I have to try to resurrect the Miniscribe 8425 20MB SCSI hard drive: it makes a head re-seeking sound every 7 seconds, but I don’t know if it’s the drive’s fault or Emax’s…
When I had the internal drive die on me years ago, I swapped it out with a 80mb quantum hard drive instead of trying to repair the miniscribe. it was smaller and quieter then the miniscribe.
Nice work on the floppy mod.
It would be nice to have a quieter drive. Being in the same room with the Miniscribe is akin to being on a tarmac with an idling Boeing 737.
I don’t see any mechanism for formatting a new hard drive on the Emax - how is that done?
My, you’re just a font of information.
Master 7 is Wes Swift’s epic Birdrun program - you meant Master 0 (Special) then 7.
So, it turns out my hard drive isn’t completely horked - if I load SW (v1.1) from floppy, I am then able to access banks on the hard drive. However, the lower banks (01-09) don’t work - either outright disk errors or data errors in bank load. And the sector that holds the SW is apparently bad too so I can’t boot from HD. Even after reformatting I get the same errors on the lower banks. The HD Scan diagnostic shows “no errors found”, oh well.
So I think I’ll be able to limp along with booting from floppy and only using HD banks 10-36. That should get me by for another decade.
Thanks for all your help!