\ SEDCODE.SEQ   The Assembly code needed for SED        by Tom Zimmer

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code tb:        ( a1 -- tsegb a1 )      \ add text segment base to stack
                pop ax                  \ under a1 in prep for long operation
                mov dx, tsegb
                2push
                end-code

code tl:        ( a1 -- lseg a1 )       \ add list segment base to stack
                pop ax                  \ under a1 in prep for long operation
                mov dx, lseg
                2push
                end-code

code tl+        ( a1 --- a2 )   \ a2 = a1 + 2, the list entry size in bytes
                pop ax          add ax, # 2
                1push           end-code

code tl-        ( a1 --- a2 )   \ a2 = a1 - 2, the list entry size in bytes
                pop ax          sub ax, # 2
                1push           end-code

code tl*        ( n1 -- n2 )    \ n2 = n1 * 2, the list entry size in bytes
                pop ax          shl ax, # 1
                1push           end-code

code ?exit      ( f1 -- )  \ exit from definition on boolean f1.
                pop ax
                or ax, ax
        0<> if
                jmp ' exit
        then
                next
                end-code

code getdiskfree        \ return free space from disk
                ( dv --- avail.clusters bytes/sec secs/cluster )
                mov ah, # 54
                pop dx
                int 33
                push bx
                push cx
                1push
                end-code

code >lineptr   ( n1 --- a1 )
                pop ax
                shl ax, # 1
                1push
                end-code

code lineptr   ( --- a1 )
                mov ax, ' curline >body
                shl ax, # 1             \ shift left by 2, for word size
                1push                   \ of list pointer table.
                end-code

code tl:@       ( a1 -- n1 )
                pop bx          mov ds, lseg
                mov ax, 0 [bx]
                mov bx, cs      mov ds, bx
                1push           end-code

code tl:!       ( n adr -- )
                pop bx          mov ds, lseg
                pop ax          mov 0 [bx], ax
                mov bx, cs      mov ds, bx
                NEXT            END-CODE

code #linedata  ( n1 --- a1 n2 )        \ n1 = line, a1,n2 = addr & len
                pop bx                  \ get line number
                shl bx, # 1             \ convert to word offset
                mov ds, lseg            \ set DS to Linelist segment
                mov ax, 0 [bx]          \ get line address
                push ax                 \ push it
                mov dx, ax              \ save to subtract later
                mov ax, 2 [bx]          \ get next list address
                sub ax, dx              \ subtract to get line length
                mov bx, cs
                mov ds, bx              \ restore DS
                1push           end-code

code clipline ( a1 n1 --- a2 n3 )
                mov bx, ' screenchar >body      \ get the value of screenchar
                pop cx
                pop dx
                mov ax, # 40
        begin
                cmp bx, # 79
        > while
                sub bx, ax
                sub cx, ax
                add dx, ax
        repeat
                push dx
                push cx
                next
                end-code


code qmod       ( n1 n1 -- Remainder )          \ a quick modulus operator
                pop bx          mov dx, # 0
                pop ax
                div bx          push dx
                next
                end-code

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