dr.zeissler wrote on 2025-07-02, 17:41:

Can these IBM-Drives technically be used with the LPT or serial port and not on FDC ?

Probably not. Connector pinout from a later Sunix SUN-4310 internal/external floppy controller manual:

So normal 34 pin floppy pinout with added 12 and 5 volt power lines for the external drive. Yeah 5V is misprinted as 15V.

Manual avalable at Minuszerodegrees https://minuszerodegrees.net/manuals.htm#Sunix
archived from the good Vintage Computer people https://forum.vcfed.org/index.php?threads/jcc … ntroller.40600/

Too bad IBM PS/2 machines cannot be fitted with two MCA FDD controllers for two external 5,25" drives (1,2/360).