You can developp very freely, even the RST vectors are free usable. Also the second register set of the Z80 is freely usable.
=== * '''Z80 Assembler ===:''' You can use an assembler for AmsDOS or for CP/M. Switching between AmsDOS and FutureOS is fast and using |FDESK allows to come back to AmsDOS with the first 48 KB or RAM remaining untouched.
=== * '''Programming in C for FutureOS ===It :''' With [[FIOLIB]] it also possible to use C as a programming language. There is a CP/M version of Small-C and also Windows-based cross-compilers of the C language. You have to use [[FIOLIB]].C instead of IOLIB.C. becase [[FIOLIB]].C contains all C functions to use FutureOS system-calls. You can use a normal C program compile it, assemble it, link the object-code with [[FIOLIB]] (an all other needed libraries) and add a header to the *.COM file with COMFU.COM. To start such an C-program under FutureOS you have to start the RUNC-environment. RUNC expands the features of [[FIOLIB]]. With RUNC it is possible to store functions in E-RAM, leaving more main memory free for applications.
== Applications ==