My program  http://www.merlyn.demon.co.uk/programs/fsincos.pas works  in
BP7 DOS & DPMI modes, crashes in BPW, and is, I am told, rejected by
Delphi 2.0 -

"Unfortunately the compiler complains with "Invalid registercombination"
(roughly translated from my german Delphi-version).
Here is the code I used:
procedure FSinCos(var S, C : extended ; A : extended) ; assembler ;
asm  fld [A] ; db $CD,$35,$FB { >287: => fsincos; fpatan is CD35F3 } ;
  les di,[C] ; fstp es:tbyte ptr[di] ;
(**********************************^ stops here **********)"

The full source of the subroutines is

procedure FSinCos(var S, C : extended ; A : extended) ; assembler ;
asm  fld [A] ; db $CD,$35,$FB { >287: => fsincos; fpatan is CD35F3 } ;
  les di,[C] ; fstp es:tbyte ptr[di] ;
  les di,[S] ; fstp es:tbyte ptr[di] ;
  end {FSinCos} ;

function FTan(A : extended) : extended ; assembler ;
asm  fld [A] ; db $CD,$35,$FB { >287: => fsincos; fpatan is CD35F3 } ;
  FDIV  end {FTan} ;  (* OK? *)

function FCot(A : extended) : extended ; assembler ;
asm  fld [A] ; db $CD,$35,$FB { >287: => fsincos; fpatan is CD35F3 } ;
  FDIVR  end {FCot} ;  (* OK? *)

Comments?   Corrections?

BTW, has anyone got a way for a BP7 DOS/DPMI program to switch between
25- and 43/50- line modes without "uses Crt;" ?

        CD 35 FB  use   D9 FB

You may use the regular opcode in a DOS or DPMI program, too, because
the procedure can't run without FPU anyway, as the emulator doesn't
support fsincos.