Dear friends, I need your help!
Yesterday I connected the floppy drive to my Opus clone, but I had some malfunction.
I' using a Mitshubishi MF535 720K drive (I used with my original Opus too)
For now I have connected only one drive and therefore I have only one data cable and one power supply cable connected.
When I turn it on I get the regular QuickDos icon but as I try to give a simple CAT 1 command the response from Opus is unpredictable, and almost always ends with a reset.
Sometimes drive spi-up, sometimes no. The drive led might be on forever or (like it should be9<only when drive spin-up. Sometimes the drive led never shut down...
Some info about my setup.
- I'm using a 27C64 Eprom with QuickDos taken from the original Opus I have.
- I have set the two jumpers for ROM selection, all to GND connection (is it right?).
- I tried different combinations of the AB / BA jumper; it seems to me that one or the other must be closed (pin 2 of MC6821 to pin 1 of U15 or pin 3 of MC6821 to pin 5 of U15).
- My board have a WD 1770, thaken from the original Opus, instead a WD1772.
- I use the 128K (grey) power supply of the Spectrum at 9v.
- Drive is set as DS0 (I tried also DS1 but also impredictable response appened).
Something is wrong, but how can I test and what check to solve the problem?
Can you give me a safe setup of AB/BA pins and ROM selection, and alo for DS0/1 of the drive?
Maybe let me know if there are any measurements I can take to test the individual sections of the circuit.
Thank you, I await your comments
Claudio