Move EMIT out of the kernel, saving 12 bytes

README.md

@@ -4,7 +4,7 @@
 The following standard words are available:
 
 ```
-- ! @ c! c@ dup swap emit u. >r r> : ; load
+- ! @ c! c@ dup swap u. >r r> : ; load
 ```
 
 Additionally, there are two non-standard words.
@@ -181,8 +181,8 @@ Git or GitHub's web interface. This disparity is handled by two Python scripts:
 
 ## Free bytes
 
-At this moment, not counting the `55 AA` signature at the end, **462** bytes are used,
-leaving 48 bytes for any potential improvements.
+At this moment, not counting the `55 AA` signature at the end, **450** bytes are used,
+leaving 60 bytes for any potential improvements.
 
 Byte saving leaderboard:
  - Ilya Kurdyukov saved 24 bytes. Thanks!
@@ -191,8 +191,6 @@ Byte saving leaderboard:
 
 If a feature is strongly desirable, potential tradeoffs include:
 
- - 12 bytes: Remove the `emit` word - we need loops to make good use of it, and
-   by that point we can assemble it ourselves.
  - 7 bytes: Don't push the addresses of variables kept by self-modifying code. This
    essentially changes the API with each edit (NOTE: it's 7 bytes because this makes it
    beneficial to keep `>IN` in the literal field of an instruction).

blocks/bootstrap.fth

@@ -47,19 +47,19 @@ variable pos                    : pos, pos @ ! 2 pos +! ;
 : [  1 st c! ; immediate        : ]  0 st c! ;               -->
 
 : rep, F2 c, ;    : cld, FC c, ;    : std, FD c, ;
-: cmpsb, A6 c, ;  : cmpsw, A7 c, ;
-: notw-r, F7 c, 2 rm-r, ;
+: cmpsb, A6 c, ;  : cmpsw, A7 c, ;  : notw-r, F7 c, 2 rm-r, ;
 : [bx+si] 0 ;  : [bx+di] 1 ;  : [bp+si] 2 ;  : [bp+di] 3 ;
 : [si] 4 ;  : [di] 5 ;  : [#] 6 ;  : [bp] 6 ;  : [bx] 7 ;
 : m-r, 3shl + c, ;              : r-m, swap m-r, ;
 : movw-mr, 8B c, m-r, ;         : movw-rm, 89 c, r-m, ;
 :code or   ax pop,  ax bx orw-rr,   next,
 :code and  ax pop,  ax bx andw-rr,  next,
 :code xor  ax pop,  ax bx xorw-rr,  next,
+:code emit  bx ax movw-rr,  0E ah movb-ir,  bx bx xorw-rr,
+  10 int,   bx pop,  next,
 : jz, 74 c, ;   : jnz, 75 c, ;
 : j> here 0 c, ;  : >j dup >r 1 + here swap - r> c! ;
 : j< here ;       : <j here 1 + - c, ;
-
 : :cmp  :code  ax ax xorw-rr, ;
 : cmp;  j> ax decw, >j  ax bx movw-rr,  next, ;              -->
 :cmp 0=  bx bx orw-rr, jnz, cmp;

boot.s

@@ -119,13 +119,17 @@ ReadLine:
     db 0x3c          ; mask next instruction
 .write:
     stosb
-    call PutChar
+
+    xor bx, bx
+    mov ah, 0x0e
+    int 0x10
+
     cmp al, 0x0d
     jne short .loop
 .enter:
     mov al, 0x0a
     int 0x10
-    mov [di-1], bl ; write the null terminator by using the BX = 0 from PutChar
+    mov [di-1], bl ; BX = 0 at this point
     pop bx
 InterpreterLoopSaveBX:
     push bx
@@ -231,12 +235,6 @@ ParseWord:
     lodsb
     jmp short .takeloop
 
-PutChar:
-    xor bx, bx
-    mov ah, 0x0e
-    int 0x10
-    ret
-
 DiskPacket:
     db 0x10, 0
 .count:
@@ -311,11 +309,6 @@ defcode FROM_R, "r>"
     push bx
     mov bx, [di]
 
-defcode EMIT, "emit"
-    xchg bx, ax
-    call PutChar
-    pop bx
-
 defcode UDOT, "u."
     ; the hexdigit conversion algo below turns 0x89 into a space.
     ; 0x89 itself doesn't fit in a signed 8-bit immediate that
@@ -336,7 +329,10 @@ defcode UDOT, "u."
     adc al, 0x40
     daa
 
-    call PutChar
+    xor bx, bx
+    mov ah, 0x0e
+    int 0x10
+
     cmp al, " "
     jne short .print
     pop bx