Hi Alan,
welcome back to the group :)
I resonate with you about the quality of the last HP manuals....
You might find some consolation by downloading and reading the good ol' 48G series manual
(as far as programming RPL programming is concerned):
http://www.hpcalc.org/hp48/docs/misc/hp48gaur.zip
or the 49G user guide as far as getting to know how the 50G can be (almost fully) exploited:
http://www.hpcalc.org/hp49/docs/misc/hp49gpugb.zip
Please consider that 99% of what you can learn about the 49G+ hold trus for the 50G as well - and the manual is better....
Turning to your specific issue, you might find helpful to read this (long) thread on comp.sys.hp48
(which is, by the way and IMHO, a better place to find help about the 50G than HP Museum forum):
http://groups.google.com/group/comp.sys.hp48/browse_frm/thread/fea856d8f18cab28/5325118f3c1de62b?lnk=gst&q=50g+CONNECTION+TO+PC&rnum=9#5325118f3c1de62b
Last but not least, as far as transferring files between a PC and a 50G is concerned,
I'd strongly advise to use a SD card instead of the ConnKit (which I myself struggled a bit to get to work).
Hope this helps.
Best regards.
Giancarlo