VolksForth/msdos/asm.fb

\ 8086 Assembler                                     cas 10nov05This 8086 Assembler was written by Klaus Schleisiek.            Assembler Definitions are created with the definig word         CODE and closed with the word END-CODE.                                                                                         The 8086 Registers naming and usage in volksFORTH                                                                               Intel vForth  Used for                   8bit-Register          AX      A     free                           A+ A-              DX      D     topmost Stackitem              D+ D-              CX      C     free                           C+ C-              BX      R     Returnstack Pointer            R+ R-              BP      U     User Pointer                                      SP      S     Stack Pointer                                     SI      I     Instruction Pointer                               DI      W     Word Pointer, mostly free                         \ 8086 Assembler   loadscreen                        cas 10nov05  Onlyforth                                                                                                                     | : u2/ ( 16b -- 15b )   2/ $7FFF and ;                         | : 8*  ( 15b -- 16b )   2* 2* 2* ;                             | : 8/  ( 16b -- 13b )   u2/ 2/ 2/ ;                                                                                              Vocabulary Assembler                                            Assembler also definitions                                                                                                      3 &21 thru clear  .( Assembler loaded ) cr                                                                                                                                                                                                                                                                                                                                                    \ conditional Assembler compiler                     cas 10nov05  here                                                                                                                            : temp-assembler  ( addr -- )  hide  last off  dp !                " ASSEMBLER"  find nip ?exit   here $1800 + sp@ u>              IF  display cr ." Assembler won't fit" abort  THEN              here   sp@ $1800 - dp !  1 load   dp ! ;                                                                                     temp-assembler   \\                                                                                                             : blocks   ( n -- addr / ff )                                      first @ >r   dup 0 ?DO  freebuffer  LOOP                        [ b/blk negate ] Literal * first @ +   r@ u> r> and ;                                                                                                                                                                                                      \ Code generating primitives                         cas 10nov05                                                                  Variable >codes  \ points at table of execution vectors                                                                       | Create nrc  ] c, , here ! c! [                                                                                                  : nonrelocate  nrc >codes ! ;  nonrelocate                                                                                    | : >exec ( n -- n+2 )   Create dup c, 2+                           Does> c@  >codes @ + perform ;                                                                                              0 | >exec >c,       | >exec >,       | >exec >here                | >exec >!        | >exec >c!   drop