Andy the TASM is a old cross assembler for 8051,8048,6502,6800,68000.....
(not from Borland)
But i have used the ASM51 from Analog Device WEB-Sites it works good.
Its the same Assembler from Philips WEB-Site.
You must only change the pseudo opcodes.
(Byte=DB Word=DW.....)
Sascha