Marching to Zion by Larry Pile is a very helpful book on the early history of GCx, starting with the early "Blitz" days. Right now it is only available in paper format from the author.
Larry said it is OK to post his address. Send check to
Larry Pile
32438 McGinnis Rd.
Albany, OH 45710
His email is
cltexprt511@yahoo.comTell him your snail-mail address (for the book) and e-mail address (in case there are questions).