Want to borrow a known good card? Not the prototype though I consider it to fragile. If a wire broke off would have a hell of a time trying to figure out where it went. Let me know by PM. I realize your are in the UK. I think.
A couple of our NFL teams played in London yesterday. Miami and Oakland and Miami won. So being from Florida you can guess who I was routing for!
I know folks way off topic...Sorry to deviate. Let me know how it goes with the replacement part.
I'm using an 8gb CF card with an adapter. It turns out that I have to supply power directly to the adapter. The power coming through on pin 20 is not enough. I don't want to modify the adapter, so I ordered the power connector (the ones I had here had wires too short) and I'll solder in the cable to the Lo-Tech card. Hopefully, that will solve my problem.
DaneElec 512 CF
SanDisk Ultra II CF
Kingston 16GB CF
I did previously try with a real hard drive too (independently powered).
I've tested the power lines on the CF card socket, they are showing voltage (see my earlier posts), and I have also checked as many signal lines as possible (again, see my earlier posts). The card adapter 's 4 pin power plug is connected to the screw terminals.
I'm wondering if it is the way I'm powering it. Connected to a USB port on my PC. Maybe it's not getting enough current. Surely it doesn't need more than 50mA.
IDE works by commands being provided by writing to device registers (i.e. ports), then waiting for the drive to set a ready flag (in which time the status register is polled, i.e. read from repeatedly), and then data read (or writing) by reading from (or writing to) the data port. It's possible that test.com is simply sitting there waiting for the ready flag to be set forever, *however* the device should assert /DASP (and so turn on the activity LED) until the command has been completed. That the LED is not lit implies that the command was never received.
Might be worth checking continuity between U3 pin 5 (/OUT) and the TRS-80 end of the cable (pin 35).
I just looked at my Model 4 and the 50 Pin connector has 2 thru 50 (GND) facing towards the back of the Model 4.
That makes Pin 1 facing the Front of the computer and Pin 1 is the one further away from the Power Cord.
Another thing you should verify is that Pin 1 is the same on the 50 Conductor cable, because some of the
Connectors are made different and if you used two different brands of Connectors for the ends of the cable
that can switch the signals. So, verify at least four pins on both ends of the cable are correct.
The Model 4 Schematic has RP3 shown as being used for a PULLUP resistor, but my Board does not have RP3 installed
for that 50 Pin connector.
I've had problems where a PULLUP resistor did not PULLUP the Line because of a bad Solder connection.
The other PULLUP resistors you might want to check are: