Since TI-8* calculators all uses Z80 CPU for processing. Is it possible that SDCC can output the same format that the TI-8* assembly language calls for?
Yes it is possible.
Change the z80 crt0.s file to suport whatever system you desire. Then re-assemble it with
as-z80 -glo crt0.o crt0.s
I'd imagine that you'd also have to change the output file format. Or does crt0.s also control the header data and output format of one of the output files?
Say I were to rewrite crt0.s to target Texas Instruments calculators, would you be interested in having it? Or has it already been done by someone?