VolksForth/8086/msdos/serial.fb

\ Serial interface for IBM-PC using 8250 chip        cas 11nov05                                                                 INCLUDE SERIAL.FB  will load code for COM1,                     2 LOADFROM SERIAL.FB  for COM2                                                                                                 Bytes recieved will be buffered in a 128 Byte deep Queue        by an interrupt Routine.                                                                                                        The DTR Line will be used to signal that new bytes can be       recieved.                                                       The Sender will recognize CTS, a full Handshake is implemented                                                                  Xon/Xoff Protocoll using ^S/^Q is _not_ implemented.                                                                            Sender:     TX? ( -- f )      TX ( -- char )                    Empf„nger:  RX? ( -- f )      RX ( char -- )                    \ Driver for IBM-PC Serial card using 8250           cas 11nov05  Onlyforth   \needs Assembler  2 loadfrom asm.fb                                                                               cr .( COM1: )                                                                                                                   | $C 4 * Constant SINT@  \ absolute loc. of serial interrupt                                                                      $3F8 >label Portadr                                                                                                           | $10 Constant I_level   \ 8259 priority                                                                                          2 7 +thru                                                                                                                                                                                                                                                                                                                     \ Driver for IBM-PC Serial card using 8250           cas 11nov05  Onlyforth   \needs Assembler  2 loadfrom asm.fb                                                                               cr .( COM2: )                                                                                                                   | $B 4 * Constant SINT@  \ absolute loc. of serial interrupt                                                                      $2F8 >label Portadr                                                                                                           |   8 Constant I_level   \ 8259 priority                                                                                          1 6 +thru                                                                                                                                                                                                                                                                                                                     \ Driver for IBM-PC Serial card using 8250        ks 11 mai 88  \   3 .( 38.4 kbaud )                                           \  &6 .( 19.2 kbaud )                                             &12 .( 9.6 kbaud )                                            \ &24 .( 4.8 kbaud )                                            \ &96 .( 1200 baud )                                              >label baud                                                                                                                     $20 >label I_ctrl      $21 >label I_mask   \ 8259 addresses                                                                     Create Queue  0 , $80 allot                                   \  0     1     2                      130  byte address         \ | len | out |<-- 128 byte Queue -->|                          \ len ::= number of characters queued                           \ out ::= relativ address of next output character              \ (len+out)mod(128) ::= relative address of first empty byte    \ transmit to 8250                                ks 11 dez 87                                                                    Code tx?  ( -- f )   D push   Portadr 5 + # D mov                  D in   D D xor   $1020 # A and   $1020 # A cmp                  0= ?[  D dec  ]?   Next   end-code                                                                                           Code tx   ( c -- )   D- A- xchg   Portadr # D mov                  D byte out   D pop   Next   end-code                                                                                         Code -dtr    D push   Portadr 4 + # D mov                          D byte in   $1E # A- and   D byte out   D pop   Next         end-code                                                                                                                        Code +dtr    D push   Portadr 4 + # D mov                          D byte in   1 # A- or   D byte out   D pop   Next            end-code                                                      \ receive queue and interrupt service routine     ks 11 dez 87                                                                    Label S_INT     D push   I push   A push                           Portadr # D mov   D byte in   A- D+ mov                         Queue # I mov   C: seg I ) A mov   A- D- mov   D- inc           C: seg D- I ) mov   A+ A- add   $7F # A and   A I add           C: seg D+ 2 I D) mov   $68 # D- cmp  CS not                     ?[  Portadr 4 + # D mov                                             D byte in   $1E # A- and   D byte out  ]?  \ -DTR           $20 # A- mov   I_ctrl #) byte out          \ EOI for 8259       A pop   I pop   D pop   iret                                 end-code                                                                                                                                                                                                                                                                                                                      \ rx?  rx                                         ks 30 dez 87                                                                    Code rx?  ( -- f )   D push   D D xor                              Queue #) D- mov   D- D- or  0=                                  ?[  [[  D push   Portadr 4 + # D mov   \ +DTR                           D byte in   9 # A- or   D byte out   D pop         swap ]?  Next   end-code                                                                                                          Code rx   ( -- 8b )  I W mov   Queue # I mov                       D push   D D xor   cli   lods   A- A- or  0= not                ?[  A+ C- mov   A- dec   A+ inc   $7F # A+ and                      A -2 I D) mov   D- C+ mov   C I add   I ) D- mov            ]?  sti   W I mov   $18 # A- cmp  CS not ?]   Next           end-code                                                                                                                                                                                      \ Serial initialization                           ks 25 apr 86                                                                  | Code S_init  D push   D: push   A A xor   A D: mov   C: A mov      SINT@ # W mov   S_INT # W ) mov   A 2 W D) mov   D: pop         Portadr 3 + # D mov   $80 # A- mov   D byte out \ DLAB = 1      2 # D sub   baud # A mov   A- A+ xchg   D byte out              D dec   A- A+ xchg   D byte out                 \ baudrate      3 # D add   $A07 # A mov   D out     \ 8bit, noP, +RTS +OUT     2 # D sub   1 # A- mov   D byte out             \ +rxINT        I_mask #) byte in   I_level Forth not Assembler # A- and        I_mask #) byte out   D pop   Next                            end-code                                                                                                                                                                                                                                                                                                                      \ init  bye                                       ks 11 dez 87    \needs init   : init ;                                                                                                          : init   init   Queue off  S_init ;  init                                                                                       : bye    0 [ Portadr 1+ ] Literal  pc!  \ -rxINT                         0 [ Portadr 4 + ] Literal pc!  \ -dtr/-rts/-out2                I_mask pc@ I_level or I_mask pc! bye ;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               \ dumb terminal via 8250                          ks 11 dez 87                                                                    Variable Fkeys   Fkeys on                                                                                                     | : ?rx   ( -- )   pause rx? 0=exit rx                               Fkeys @ 0= IF  emit ?cr exit  THEN                              #LF case? IF  cr       exit    THEN                             #CR case? IF  Row 0 at exit    THEN                             #BS case? IF  del exit  THEN   emit ;                                                                                      | : ?tx   ( c -- )   BEGIN ?rx tx? UNTIL tx ;                                                                                     : dumb   BEGIN BEGIN  ?rx key?  UNTIL  key                                     $1B case? IF -dtr exit THEN ?tx REPEAT ;