Category : Forth Source Code
Archive   : STREAMIO.ZIP
Filename : LINKS.TXT

\ LINKS.TXT Support for Linked Lists. Also bit access words.

ONLY FORTH ALSO DEFINITIONS

POSTFIX \ Declare assembler syntax.

\ The following words are used to link and unlink elements in a linked list

CODE link- ( adr1,n--adr2) \ result is adr2 = (adr1) and (adr1) = (adr2+n)
DX POP AX POP AX BX MOV
0 [BX] BX MOV BX CX MOV \ a=*rec b=c=rec d=.next
DX BX ADD 0 [BX] DX MOV AX BX XCHG
DX 0 [BX] MOV CX PUSH NEXT END-CODE \ rec:=[rec.next]


CODE link+ ( adr1,adr2,n--) \ result is (adr2) = adr1 and (adr1+n) = (adr2)
DX POP BX POP AX POP 0 [BX] CX MOV AX 0 [BX] MOV
AX BX XCHG DX BX ADD CX 0 [BX] MOV NEXT END-CODE


CODE xlink- ( seg,adr1,n--adr2) \ 880827z
DX POP AX POP DS POP
AX BX MOV 0 [BX] BX MOV BX CX MOV \ a=adr1 b=c=adr2 d=n
DX BX ADD 0 [BX] DX MOV AX BX XCHG
DX 0 [BX] MOV CX PUSH \ (adr1) = (adr2+n)
CS AX MOV AX DS MOV NEXT END-CODE \ (adr1) = (adr2+n)


CODE xlink+ ( seg,adr1,adr2,n--) \ 880827z
DX POP BX POP AX POP CX POP CX DS MOV
0 [BX] CX MOV AX 0 [BX] MOV
AX BX XCHG DX BX ADD CX 0 [BX] MOV
CS AX MOV AX DS MOV NEXT END-CODE


LABEL (bit) ( ptr,bit,adr--)
AX POP BX POP DX POP \ d=ptr b=bit a=return address
BL CL MOV 7 # CL AND
BX SHR BX SHR BX SHR
DX BX ADD AX JMP END-CODE


CODE bit@ ( ptr,bit -- 0/1)
(bit) #) CALL 0 [BX] BL MOV BL CL SHR 1 # BX AND BX PUSH NEXT END-CODE

HEX

CODE bit0! ( ptr,bit --)
(bit) #) CALL 0FE # AL MOV AL CL ROL AL 0 [BX] AND NEXT END-CODE

CODE bit1! ( ptr,bit --)
(bit) #) CALL 01 # AL MOV AL CL ROL AL 0 [BX] OR NEXT END-CODE

DECIMAL