Today while hunting for vintage camera gear at a local flea market I ran across a very nice looking SOLIGOR 30D flash unit (for canon A1, AE-1...) it's packed with spiffy features and for $5 I had to have it. Now I searched the internet high and low but no info or instructions are to be found. It's a nice flash and appears to be working fine. It does have some nonstandard controls I'd like to know what they're about. any insight?