inline(

{;}

{; Check if any characters in input comm buffer}

{;}

$A1/>ASYNC_BUFFER_TAIL/ { MOV AX,[>Async_Buffer_Tail]}

$3B/$06/>ASYNC_BUFFER_HEAD/ { CMP AX,[>Async_Buffer_Head]}

$75/$0B/ { JNE Rec1}

{;}

{; Buffer is empty -- return NUL character}

{;}

$C4/$7E/<C/ { LES DI,[BP+<C] ;Get character address}

$31/$C0/ { XOR AX,AX ;Clear out unused bits}

$26/$88/$05/ { ES: MOV [DI],AL ;NUL character}

$E9/$3F/$00/ { JMP Return}

{;}

{; Buffer not empty -- pick up next character.}

{;}

$C4/$3E/>ASYNC_BUFFER_PTR/ {Rec1: LES DI,[>Async_Buffer_Ptr] ;Pick up buffer address}

$01/$C7/ { ADD DI,AX ;Add character offset}

$26/$8A/$1D/ { ES: MOV BL,[DI] ;Get character from buffer}

$C4/$7E/<C/ { LES DI,[BP+<C] ;Get result address}

$26/$88/$1D/ { ES: MOV [DI],BL ;Store character from buffer}

$40/ { INC AX ;Increment tail pointer}

$3B/$06/>ASYNC_BUFFER_SIZE/ { CMP AX,[>Async_Buffer_Size] ;Past end of buffer?}

$7E/$02/ { JLE Rec2 ;No -- skip wrapping}

$31/$C0/ { XOR AX,AX ;Yes -- point to start of buffer}

$A3/>ASYNC_BUFFER_TAIL/ {Rec2: MOV [>Async_Buffer_Tail],AX ;Update tail pointer}

$FF/$0E/>ASYNC_BUFFER_USED/ { DEC Word [>Async_Buffer_Used] ;Update buffer use count}

{;}

{; If XOFF previously sent because buffer was too full, and}

{; now buffer is reasonably empty, send XON to get things rolling again.}

{;}

$90/$90/$90/$90/$90/ { NOP NOP NOP NOP NOP }

$EB/$16/ { JMP Rec3 ;Skip.}

(* $F6/$06/>ASYNC_XOFF_SENT/$01/ { TEST BYTE [<Async_XOff_Sent],1 ;Check if Xoff sent}*)

(* $74/$16/ { JZ Rec3 ;No -- skip.}*)

{;}

$A1/>ASYNC_BUFFER_USED/ { MOV AX,[>Async_Buffer_Used] ;Pick up amount of buffer used}

$3B/$06/>ASYNC_BUFFER_LOW/ { CMP AX,[>Async_Buffer_Low] ;Check if low enough}

$7F/$0D/ { JG Rec3 ;Still too full, skip}

{;}

$B8/>XON/ { MOV AX,>XON ;Else push XON onto stack}

$50/ { PUSH AX}

$FF/$1E/>ASYNC_SEND_ADDR/ { CALL FAR [>Async_Send_Addr] ;Call output routine}

{;}

$C6/$06/>ASYNC_XOFF_SENT/$00/ { MOV BYTE [>Async_XOff_Sent],0 ;Clear Xoff flag}

{;}

{; Indicate character found}

{;}

$B8/$01/$00/ {Rec3: MOV AX,1}

{;}

$80/$26/>ASYNC_LINE_STATUS/$FD/ {Return: AND Byte [>Async_Line_Status],$FD ;Remove overflow flag}

$09/$C0/ { OR AX,AX ;Set zero flag to indicate return status}

$89/$EC/ { MOV SP,BP}

$5D/ { POP BP}

$CA/$04/$00); { RETF 4}