Re: BAT 42

I've found that BAT43, BAT48 and BAT85 all worked fine in my ICSP.

I don't know anything about the programmer you mention but I guess they're simply specifying a small signal, fast, Schottky diode.

If you don't mind a fatter diode then a 1N5818 will probably do.

I've never tried a 'normal' signal diode, it may work, but no doubt you will messages of doom about them.