I have toshiba HX-F101 (japan) external floppy drive unit, that is missing the cartridge part. Does anybody have this unit and could take good photos from both sides of the PCB? But even with pictures, there would be some signals hidden under the ICs still.
Based on the other topic in here, https://www.msx.org/forum/msx-talk/hardware/toshiba-hx-f101-... , the HX34 diskrom was used successfully in HX-F101 cartridge. And it was mentioned that same addressing is used in both HX34 and HX-F101 cartridge.
So I tried to check the implementation between toshiba HX34 mainboard floppy circuit and the external unit circuit that I have, and then the one picture from that cartridge component side:
http://www.retrocomputacion.com/e107_files/public/1404066639...
I tried to draw schematics, but there are missing pieces.
the connector cable between cartridge and unit has 34 pins (marked in schema as PB1-PB34, odd pins are ground)
I traced backwards the signals from these PPB2-PB34 signals, and almost same was found from mainboard, but the 74LS133 input signal logic (for ENABLE signal) was not exactly same. Would this be working same way if the PB16 input would be generated via different logic in HX34 and HX-F101 cases? I assumed same logic to generate PB16, but it cannot be true as all the same signals in mainboard case are not available in slot interface. So what would be logic for this PB16 signal, i.e. 74LS133 input signals?
And in that cartridge component side picture, it can be seen that OR output (U4C) output is connected to NAND input (U8A), but I did not find that kind of connection in HX34 mainboard.
Does anybody have clues how to complete this schematics?