Added port support, and removed things from BASIC_DEVELOPMENT it does not yet support

data/hello.bas

@@ -1,17 +1,2 @@
-$1 = "_________"
+PORT OUT 80 5
-A = & $1
-FOR X = 1 TO 9
-	FOR Y = 1 TO 9
-		PEEK B A
-		IF B = 95 THEN PRINT "_" ;
-		IF B = 88 THEN PRINT "X" ;
-		IF B = 79 THEN PRINT "O" ;
-		C = A % 3
-		IF C = 0 THEN PRINT " "
-		A = A + 1
-	NEXT Y
-	Z = X % 2
-	IF Z = 0 THEN PRINT "You are X"
-	IF Z = 1 THEN PRINT "You are O"
-NEXT X
 END

docs/BASIC_DEVELOPMENT.md

@@ -81,19 +81,6 @@ input $1
 
 ## Keywords
 
-You can do this to get the MikeOS API version number:
-```
-x = VERSION
-```
-Or you can retrieve the lower word of the system clock like this:
-```
-x = TIMER
-```
-To get the current ink colour, use:
-```
-x = INK
-```
-
 ## The editor
 
 You can run your .BAS programs by using the BAS core util eg.
@@ -176,13 +163,6 @@ Get the position of the cursor. Example:
 curspos a b
 ```
 
-## DELETE
-
-Removes a file from the disk. Returns 0 in the R variable if the operation was a success, 1 if the delete operation couldn't be completed, or 2 if the file doesn't exist. Example:
-```
-delete "myfile.txt"
-```
-
 ## DO
 
 Perform a loop until a condition is met (UNTIL or WHILE). You can also set up an infinite loop with LOOP ENDLESS at the end. Example:
@@ -205,10 +185,6 @@ else print "Goodbye"
 
 Terminates execution of the BASIC program and hands control back to the operating system.
 
-## FILES
-
-Prints a list of files that are on the disk on the screen.
-
 ## FOR
 
 Begins a loop, counting upwards using a variable. The loop must be finished with a NEXT instruction and the relevant variable. Example:
@@ -423,15 +399,6 @@ print hex x
 ```
 In the first print command, the output is 109. In the second, the output is the ASCII character for 109 -- that is, 'm'. And in the third command, it shows the hexadecimal equivalent of 109.
 
-## RAND
-
-Generate a random integer number between two values (inclusive) and store it in a variable. Example:
-```
-Make X a random number between 50 and 2000
-
-rand x 50 2000
-```
-
 ## READ
 
 Read data bytes from a label, first specifying the offset and a variable into which to read. For instance, in the following example we read a small program and poke it into memory locations 50000 to 50012. We then call that location to run the program:
@@ -453,14 +420,6 @@ mydata:
 190 87 195 232 173 60 195 89 111 33 13 10 0
 ```
 
-## RENAME
-
-Renames one file to another. Literal strings and string variables are allowed. Afterwards, R contains 0 if the operation was a success, 1 if the file was not found, 2 if the write operation failed, or 3 if the target file already exists. Example:
-```
-$1 = "myfile.dat"
-rename "oldfile.txt" $1
-```
-
 ## RETURN
 
 Switches execution back to the position of the prior GOSUB statement. See GOSUB above for more information. Example:
@@ -468,17 +427,6 @@ Switches execution back to the position of the prior GOSUB statement. See GOSUB
 return
 ```
 
-## SAVE
-
-Saves data from memory to a file on the disk. The first parameter is the filename, the second the location in RAM where the data starts, and the third the number (in bytes) the amount of data to save. After execution, the R variable contains 1 if the file save operation failed (eg if it's a write-only medium), 2 if the file already exists, or 0 if it was successful. Examples:
-```
-save "myfile.txt" 40000 256
-
-$1 = "myfile.txt"
-x = 40000
-y = 256
-save $1 x y
-```
 
 ## STRING
 

source/kernel/features/disk.asm

@@ -354,12 +354,12 @@ disk_list_contents:
 		popa
 		ret
 
+disk_file_list:
+	ret
 disk_file_exists:
 	ret
 disk_file_size:
 	ret
-disk_file_list:
-	ret
 disk_remove_file:
 	ret
 disk_rename_file:

source/kernel/features/keyboard.asm

@@ -1,4 +1,5 @@
 ; AX = key pressed
+; Waits until key is pressed before returning
 os_read_input:
 	mov ah, 11h			; BIOS call to check for key
 	int 16h				; Interrupt
@@ -12,6 +13,16 @@ os_read_input:
 		int 16h
 		ret
 
+; AX = key pressed
+; Returns straight away
+keyboard_check_key:
+	xor ax,ax
+	mov ah, 11h			; BIOS call to check for key
+	int 16h				; Interrupt
+	jz .no_key
+	.no_key:
+		xor ax,ax
+		ret
 ; -------------------------------------------
 ; IN:
 ; AX = output address
@@ -23,11 +34,6 @@ keyboard_display_input:
 	mov ax, bx
 	mov bx,20 
 
-	.loop:
-		jmp .check_key_pressed
-
-		jmp .loop
-
 	.check_key_pressed:
 		call os_read_input
 
@@ -43,7 +49,8 @@ keyboard_display_input:
 		dec bx
 
 		cmp bx, 0
-		jae .print_current_input ; Echo the user input back
+		je .enter_key           ; Once the limit is reached just enter it
+		ja .print_current_input ; Echo the user input back
 
 		jmp .check_key_pressed
 
@@ -59,7 +66,7 @@ keyboard_display_input:
 	.backspace:
 		cmp bx, 20						; Cannot backspace if the cursor is at the start
 		jb .move_cursor_back			; then .move_cursor_back
-		jmp .loop						; Else .loop
+		jmp .check_key_pressed			; Else check the next key
 
 	.move_cursor_back:
 		mov ah, 0Eh
@@ -73,7 +80,7 @@ keyboard_display_input:
 
 		inc bx
 		dec di
-		jmp .loop
+		jmp .check_key_pressed
 
 	.print_current_input: ; Echo back that character and return the key inputing
 		stosb
@@ -81,9 +88,9 @@ keyboard_display_input:
 		int 10h
 		jmp .check_key_pressed
 
-keyboard_get_cursor_pos: ;TODO
+keyboard_get_cursor_pos:
 	ret
-keyboard_wait_for_key:   ;TODO
+keyboard_wait_for_key:	
 	ret
 keyboard_show_cursor:
 	ret
@@ -91,5 +98,3 @@ keyboard_hide_cursor:
 	ret
 keyboard_move_cursor:
 	ret
-keyboard_check_key:
-	ret

source/kernel/features/ports.asm

@@ -1,7 +1,20 @@
+; IN:
+; DX = port address
+; AL = byte
 port_byte_out:
+	pusha
+	out dx,al
+	popa
 	ret
+; -----------------------------------------
+; IN:
+; DX = port address
+; OUT:
+; AL = byte from port
 port_byte_in:
+	in al, dx
 	ret
+
 port_serial_enable:
 	ret
 port_send_via_serial:

source/kernel/features/strings.asm

@@ -331,7 +331,5 @@ string_lower_case: ; to lower case
 	popa
 	ret
 
-string_input:
-	ret
 string_print_2hex:
 	ret