Driver pl532en works for HP DesignJet 750C+ on Windows 7 (64 bit).
The driver also appears to support:
· HP DesignJet 230 (D/A1) by HP
Hi, Hope this works, I have a HP DesignJet 220 running Windows 8, 64 bit, I install a USB serial card and will assign this to this printer and will connect with a USB cable and a serial to parallel adapter. Any thoughts.