Emperor4 Beam-Tube?/Early blaster weapons

I remember reading about this piece of equipment in the Essential Guide to Weapons and Technology and that it was one of the first hand-held beam weapons to hit the star wars battlefields roughly 25,000 BBY.

But in what piece of Star Wars literature is this weapon from, and when did the conventional rifle and pisotoshaped models come along because the Emperor4 is a bulky vest mounted contraption and has rate of fire of only I think one shot every 5-10 secondsaith an ammo capacity of only I think 25 shots, I am not sure about those statistics because almost all of my star wars books and stuff is packed away for the trip to Arizona.

 

Beam tubes were first mentioned in the Han Solo Adventures books, possibly Han Solo And the Lost Legacy. The ''Survivors'' living on the mountains of Dellalt had them. They were ancient weapons, relics from the days of Xim the Despot.