this is the mbr
ORG 0X7C00

MOV SI, BOOTSTRING


CALL TELETYPE
TELETYPE:
MOV AH, 0X0E
MOV AL, [SI]
CMP AL, 0
JE .EXIT
INT 0X10
INC SI
JMP TELETYPE
.EXIT:
RET

BOOT:

MOV AH, 0X02
MOV AL, 1
MOV CH, 0
MOV CL, 2
MOV DH, 0
MOV DL, 0X80
MOV BX, 0X7E00
INT 0X13

JC DISKERROR


JMP 0X0000:0X7E00

DISKERROR:

MOV AH, 0X0E

MOV AL, "?"

INT 0X10




BOOTSTRING:
DB "BOOTING!", 0
TIMES 510 - ($ - $$) DB 0;
DB 0X55, 0XAA

the kernel
ORG 0X7E00

MOV SI, KRNLHI
CALL NEWLN
CALL WRITE
CALL NEWLN
MOV SI, KRNLSTORY
CALL WRITE
CALL NEWLN
                        ; msdos.sys is 0x7e00, io.sys is 0x8600, and command.com is 0x8800
CALL 0X8800




WRITE:
MOV AH, 0X09
CALL 0X8600
RET
NEWLN:
MOV AH, 0X07
CALL 0X8600

RET
JMP 0X8000
KRNLHI DB "PANTERUTA DOS Kernel Loaded!", 0
KRNLSTORY DB "Hello, this is a DOS kernel made by me, named after my cat Panteruta. I am just 13 so don't expect this DOS to do anything super complex, but i would love it being able to run a basic os like Windows 1.0 in the future!", 0
times 2048 - ($ - $$) db 00
command.com
ORG 0X8800
 MOV CH, "C"
 MOV BL, 0
COMMAND:


CMP CL, 1
JE COMMAND_INTERPRETER
JMP COMMAND_OUTPUT
RET

COMMAND_OUTPUT:
MOV BH, 0

MOV SI, CMD
CALL NEWLN
MOV AL, CH
INT 0X10
CALL WRITE
CALL INPUT
CALL COMMAND_INTERPRETER
JMP COMMAND_OUTPUT


RET

COMMAND_INTERPRETER:

MOV SI, VERCMD

MOV AX, 0
CALL .READBUFFER

CMP AX, 1
JE .OUTPVER

MOV AL, VER
JE .OUTPVER
CALL NEWLN
CMP BH, 1
JE .EXITCMD



RET

.READBUFFER:

MOV AL, [SI]

.LOOP

CMP AL, 0

JE .OUTPTRUE



CMP AL, DL
JNE .OUTPFALSE
INC BH
INC AL
JMP .LOOP

.OUTPTRUE

MOV AX, 1
RET

.OUTPFALSE

RET



.OUTPVER:
CALL NEWLN
MOV SI, VER
CALL WRITE
JMP COMMAND_OUTPUT

.CMD1:

 CALL NEWLN
MOV AH, 0X0E
MOV AL, "1"
INT 0X10
JMP COMMAND_OUTPUT
.EXITCMD:

MOV SI, BCMD
CALL WRITE
CALL NEWLN
JMP COMMAND_OUTPUT
RET

















WRITE:

MOV AH, 0X09
CALL 0X8600

RET
NEWLN:

MOV AH, 0X07
CALL 0X8600

RET

INPUT:
MOV AH, 0X08
CALL 0X8600

RET











VERCMD:
DB "V", 0




















CMD:
DB ":\>", 0



BCMD:
DB "Bad Command or File Name", 0

VER:
DB "Panteruta DOS Version 1.0", 0
times 4096 - ($ - $$) db 00

I/O
ORG 0X8600

OUTPUT:
MOV DX, 0
CMP AH, 0X09


JE .TELETYPE


CMP AH, 0X07
JE .NEWLINE

CMP AH, 0X08
JE .INPUT


.TELETYPE:

MOV AH, 0X0E

MOV AL, [SI]


CMP AL, 0
JE .END

INT 0X10
INC SI
JMP .TELETYPE

.END:

RET


.NEWLINE:

MOV AH, 0X0E
MOV AL, 0X0A
INT 0X10
MOV AL, 0X0D
INT 0X10

RET

.INPUT:

MOV DI, BUFFER

MOV AH, 0X00
INT 0X16
CMP AL, 13
JE .JMPFROMINPUT
MOV [DI], AL
INC DI

MOV AH, 0X0E
INT 0X10
MOV BH, 1


JMP .INPUT

.JMPFROMINPUT:
MOV  DX, [BUFFER]
RET

BUFFER:

 TIMES 128 DB 0

TIMES 512 - ($ - $$ ) DB 00