I was not able to find much info on Diamondbacks. I bought an Apex of unknown vintage and wanted to know the same thing. I ended up looking at the Shimano date codes. They were all late '92 so I figure I have a 1993 Apex. The components description on bikepedia is a match for that year as well. Mine says "Diamond Back" with two words on the downtube. I understand later it changed to one word like on your bike. That should help get you closer anyway.
Date of Manufacture of Bicycle Components can be used to date a bike: component dating
Internet Forums. Making simple tasks complicated since 1995.
Looks post BioPace if that is the original crank set. Mid/Late 90's if it is. I just bought an late 80's/Early 90's Diamondback with BioPace rings and speckle green paint job.
Anyone know how to decipher the Diamondback serial number?
"Whenever I see an adult riding a bicycle, I know there is hope for mankind." (H. G. Wells)
A little more help on the brand and model of the components may help. Because of the parallax hubs and what loks like an Exage ES RD I a,m going to say '94ish may be a Topanga maybe a Sorrento
Bikepedia should get you close.
Bianchis '87 Sport SX, '90 Proto, '90 Campione del Fausto Giamondi Specialisma Italiano Mundo, '91 Boarala 'cross, '93 Project 3, '86 Volpe, '97 Ti Megatube, , '90 something Vento 603,
Others but still loved,; '80 RIGI, '80 Batavus Professional, '87 Cornelo, '09 Motobecane SOLD, '?? Jane Doe (still on the drawing board), '90ish Haro Escape