Improved DOS char print code

boot_code/Makefile

@@ -7,9 +7,9 @@ BUILD_FILES+=$(subst .asm,.bin,${SOURCE})
 
 all: ${BINARIES}
 
-brainfuck_interpreted.bin: brainfuck_interpreter_v0.asm hello_9086.bf.asm
-brainfuck_compiled.bin: brainfuck_compiler_v1.asm hello_9086.bf.asm
-brainfuck_mandelbrot.bin: brainfuck_compiler_v1.asm mandelbrot.bf.asm
+brainfuck_interpreted.bin: brainfuck_interpreter_v0.asm hello_9086.bf.asm dos_layer.asm
+brainfuck_compiled.bin: brainfuck_compiler_v1.asm hello_9086.bf.asm dos_layer.asm
+brainfuck_mandelbrot.bin: brainfuck_compiler_v1.asm mandelbrot.bf.asm dos_layer.asm
 
 %.bf.asm:%.bf
 	${Q}sed "s/[a-zA-Z\* ]//g;/^$$/d;s/^/.ASCII '/;s/\$$/'/" "$^" > $@

boot_code/brainfuck_compiled.asm

@@ -1,6 +1,5 @@
-.ORG 0x84           ; INT 21
-DW 0xFFFF           ; Code Segment
-DW PRINT_INT_HANDLE ; Program Counter
+; Interrupt table and routines
+INCLUDE dos_layer.asm
 
 org 0x100
 INCLUDE brainfuck_compiler_v1.asm
@@ -8,12 +7,6 @@ INCLUDE brainfuck_compiler_v1.asm
 prog:
 INCLUDE hello_9086.bf.asm
 
-PRINT_INT_HANDLE:
-push AX
-MOV AL,DL
-out byte #0xA5
-POP AX
-iret
 
 output_program:
 

boot_code/brainfuck_interpreted.asm

@@ -1,18 +1,10 @@
-.ORG 0x84           ; INT 21
-DW 0xFFFF           ; Code Segment
-DW PRINT_INT_HANDLE ; Program Counter
+; Interrupt table and routines
+INCLUDE dos_layer.asm
 
 ORG 0x100
 mov sp,#STACK
 INCLUDE brainfuck_interpreter_v0.asm
 
-PRINT_INT_HANDLE:
-push AX
-MOV AL,DL
-out byte #0xA5
-POP AX
-iret
-
  .BLKB 200
 STACK:
 

boot_code/brainfuck_mandelbrot.asm

@@ -1,17 +1,9 @@
-.ORG 0x84           ; INT 21
-DW 0xFFFF           ; Code Segment
-DW PRINT_INT_HANDLE ; Program Counter
+; Interrupt table and routines
+INCLUDE dos_layer.asm
 
-ORG 0x100
+.ORG 0x100
 INCLUDE brainfuck_compiler_v1.asm
 
-PRINT_INT_HANDLE:
-push AX
-MOV AL,DL
-out byte #0xA5
-POP AX
-iret
-
 prog:
 INCLUDE mandelbrot.bf.asm
 

boot_code/dos_layer.asm

@@ -0,0 +1,16 @@
+.ORG 0x84           ; INT 21
+DW 0xFFFF           ; Code Segment
+DW PRINT_INT_HANDLE ; Program Counter
+
+PRINT_INT_HANDLE:
+push AX
+CMP AH,#0x02
+jz PRINT_CHAR
+pop AX
+iret
+
+PRINT_CHAR:
+MOV AL,DL
+out byte #0xA5
+POP AX
+iret

system/boot_code.asm

@@ -40,6 +40,7 @@ TEST_:
 ADD AX,#0xDEAD
 RET
 
+;quick&dirty
 PRINT_INT_HANDLE:
 push AX
 MOV AL,DL