Z80 Compile

[Nick Kemp]

I'm
 trying to make a gameboy game using the gas assembler and
was trying to set the target cpu as z80 with the -z80 option but I get 
an "unrecognized option -z80" error when assembling. The command that I 
ran to compile was:

  as -z80 <filename.s> -o <filename.o>

I have looked through the manual and the webpage for how to do this but I
 can't find an answer. Could somebody explain to me if the assembler can
 actually compile a z80 object file and if it can could you tell me how? Or am I just misinterpreting the manual when it says that you can set the target platform?


Thanks
Nick