I am not sure if anyone is interested, but I've scanned the manual for the Trend HSR500 and HSR500P optical paper tape readers. If I've got the permissions right, then you can get it from my google drive on : https://drive.google.com/open?id=0B5uNCTLB4VsqRU9TWDIzWnZYaU0 It's a large file, I don't think the scanner software has heard of compression!. If anyone can make it a more reasonable size, feel free... This is a proper manual with schematics, parts lists, adjustment info, etc. I've also scanned the circuit diagrams for the Trend Paper Tape Station, here https://drive.google.com/open?id=0B5uNCTLB4VsqemRFMnVNb0l5WU0 The Paper Tape Station is a rack unit containing an HSR500 reader, power supply, GNT34 punch and a driver card for the punch. Those diagrams are for the punch driver and power supply, you need the HSR500 manual as well. Let me know if it all works... -tony