While the 1541 Ultimate 2 tape extender has a good length for the C64 and C128, it’s not long enough for the C128D, nor does it fit in the tape slot. Here’s a small hack that I’ve made to fix that.
I only had SIL headers available when I made this, so I soldered 2 x 2×5 pins together creating a 10p male-male IDC header. I had to custom make the cable as it didn’t make a 1:1 connection from the original extender cable to the tape header.
If you’re creating one like this, make note that a standard 10p IDC cable doesn’t work here as the extender cable isn’t standard connected to the header. All odd numbers on the extender cable is connected to even numbers on the IDC header, though the direction is corret. See table below for reference.
|Extender pin||IDC Cable pin|
The tape header on the extender is too wide to be plugged into the C128D. I was lazy and only connected 6 wires here, but recommended is connecting all 10 to prevent noise/stray signals (Thanks e5frog).