Don’t put the monitor on top of Timex FDD 3000, like in the pictures above. CRT generates electromagnetic field that interferes with this drive and generates significantly more read errors.
This transformer was giving 20V AC at the output.
Floppy Disk Drive
This is single-side Hitachi HFD305SXA.
It should be also possible to connect the double-side version of the drive, Hitachi HFD305D. I got it as a replacement for one of the drives that was broken, but I have not yet tried to install it.
In order to create physical 3″ floppies, connect the drive to a vintage PC. The correct drive selection jumper has to be selected on the drive. The jumper position closest to the center of the drive board is drive 0. The others are drive 1, 2 and 3. If the drive is in a chain before another drive, remember to remove the terminator from the 3″ drive – the light-blue chip closest to the edge connector. The BIOS settings that worked for me was to choose 5.25″ 360KB drive. I suppose the other settings will work too, as the raw drive write program will ignore the BIOS settings.
The boot procedure that worked for me was the following:
- Power on FDD with floppy inserted – it should do some drive activity as it reads data from it
- Power on Timex – it should reset the FDD, which should read only the first sector. Timex should print TIMEX – TOS V A.2 (or other text in case of other TOS version)
At this stage it is possible to enter floppy commands, for example CAT * to display the directory.
This interface looks like a home-made version. It has EINTMX v1 markings on the PCB. It is also missing the reset button. I saved the ROM content and it is available in the documents section. If you know anything about this interface please let me know.
Here is the original Timex interface
Here is another version of add-on PCB with visible part numbers.