diff --git a/LICENSE.MD b/LICENSE.MD
new file mode 100644
index 0000000..069c4d7
--- /dev/null
+++ b/LICENSE.MD
@@ -0,0 +1,23 @@
+MIT License
+===========
+
+Copyright (c) 2021 CrazyEttin
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
diff --git a/README.MD b/README.MD
new file mode 100644
index 0000000..aea6e75
--- /dev/null
+++ b/README.MD
@@ -0,0 +1,61 @@
+EttinOS
+=======
+
+EttinOS is a minimalist 16-bit DOS-like hobbyist operating system for
+the IBM PC and compatible computers. Its git repository can be found at
+https://ahti.space/git/crazyettin/EttinOS.
+
+System requirements
+-------------------
+
+  * An Intel 8086 or compatible CPU
+  * BIOS, or UEFI in legacy mode
+  * 64 KiB of RAM
+  * A floppy disk drive
+
+Building
+--------
+
+Build dependencies:
+  * A Unix-like operating system
+  * bash
+  * coreutils
+  * dosfstools
+  * mtools
+  * nasm
+
+Running make.sh will build EttinOS and create a bootable 360 KiB 5.25"
+floppy disk image named EttinOS.img. To get a 1.44 MB 3.5" one instead
+use the argument -1440. If you want to use another floppy disk format
+you will have to adjust the bootloader disk description tables and
+install the system manually. Hard disk drives are not supported.
+
+Input
+-----
+
+The EttinOS input system is inspired by typewriters. Typing a character
+overwrites the cursor location and the erase (=tab) key erases it. The
+space and backspace keys move the cursor.
+
+Programming
+-----------
+
+EttinOS has a flat address space of 64 KiB with the data, stack, and
+extra segments set at the beginning of the RAM. Programs are loaded at
+address 0x2000.
+
+System calls:
+  * Interrupt 0x20: Return to the shell.
+  * Interrupt 0x21: Input and output:
+      * AH = 0x0: Print a string ending in a null from SI.
+      * AH = 0x1: Read a string ending in a null of at most AL
+                  characters to DI until a return.
+      * AH = 0x2: Print a string ending in a null from SI followed by a
+                  CRLF.
+      * AH = 0x3: Read a string ending in a null of at most AL
+                  characters to DI until a return and print a CRLF.
+  * Interrupt 0x22: Disk operations:
+      * AH = 0x0: Load a file named in SI as a string ending in a null
+                  to the offset BX and set AL to 0x0 if the load was
+                  succesfull and 0x1 if there was an error.
+      * AH = 0x1: Save a file (under construction).
diff --git a/make.sh b/make.sh
index cd0971b..1feb043 100755
--- a/make.sh
+++ b/make.sh
@@ -7,11 +7,12 @@ then
 fi
 
 cd src/
-if [ "$1" == "-F1440" ]
+if [ "$1" == "-1440" ]
     then nasm BOOT.ASM -d F1440 -f bin -o ../bin/BOOT.BIN
     else nasm BOOT.ASM -f bin -o ../bin/BOOT.BIN
 fi
 nasm SYSTEM.ASM -f bin -o ../bin/SYSTEM.BIN
+nasm HELLO.ASM -f bin -o ../bin/HELLO.BIN
 
 cd ..
 if [ "$1" == "-1440" ]
@@ -20,3 +21,6 @@ if [ "$1" == "-1440" ]
 fi
 dd if=bin/BOOT.BIN of=EttinOS.img conv=notrunc bs=512 count=1
 mcopy -i EttinOS.img bin/SYSTEM.BIN ::
+mcopy -i EttinOS.img bin/HELLO.BIN ::
+mcopy -i EttinOS.img README.MD ::
+mcopy -i EttinOS.img LICENSE.MD ::
diff --git a/src/BOOT.ASM b/src/BOOT.ASM
index 4f8f289..9268925 100644
--- a/src/BOOT.ASM
+++ b/src/BOOT.ASM
@@ -63,8 +63,8 @@ cli
 mov sp, stack
 add sp, 0x100
 sti
-;Store the boot device number
-mov [bootdev], dl
+;Store the boot drive number
+mov [bootdrive], dl
 
 ;Load the root
 ;Set the source
@@ -90,7 +90,7 @@ push ax
 mov ah, 0x2
 int 0x13
 
-;Search the root for the system
+;Search the root for the system entry
 ;Set DI to the root
 mov di, 0x7f00
 ;Initialise the search loop
@@ -99,11 +99,11 @@ mov ax, 0x0
 search:
 ;Store CX in the stack
 push cx
-;Check for the system FAT
+;Check for the system entry
 mov si, sysfile
 mov cx, 0xb
 rep cmpsb
-je loadfat
+je loadentry
 ;Set DI to the next entry
 add ax, 0x20
 mov di, 0x7f00
@@ -127,7 +127,7 @@ int 0x10
 jmp printerror
 
 ;Load the system entry
-loadfat:
+loadentry:
 ;Load CX from the stack
 pop cx
 ;Store the first cluster
@@ -203,7 +203,7 @@ boot:
 jmp 0x0:0x500
 
 ;Data
-bootdev  db 0x0
+bootdrive  db 0x0
 sysfile  db "SYSTEM  BIN"
 errormsg db "System not found", 0xd, 0xa, 0x0
 cluster  dw 0x0
@@ -227,7 +227,7 @@ mov dh, dl
 mov ch, al
 pop bx
 pop ax
-mov dl, byte [bootdev]
+mov dl, byte [bootdrive]
 ret
 
 ;Pad the binary to a full sector and make the disk bootable
diff --git a/src/CMPSTR.INC b/src/CMPSTR.INC
deleted file mode 100644
index 15a8110..0000000
--- a/src/CMPSTR.INC
+++ /dev/null
@@ -1,41 +0,0 @@
-;Compares strings from SI and DI until a null and either sets the carry flag if they are equal or clears it if not.
-
-cmpstr:
-
-;Store the initial registers in the stack
-push ax
-push bx
-
-;Compare the strings
-.loop:
-;Load the current characters
-mov al, [si]
-mov bl, [di]
-;Compare the characters
-cmp al, bl
-;Check for difference
-jne .neq
-;Check for the string end
-cmp al, 0x0
-je .eq
-;Repeat for the next characters
-inc si
-inc di
-jmp .loop
-
-;Set the carry flag
-.eq:
-stc
-jmp .done
-
-;Clear the carry flag
-.neq:
-clc
-
-.done:
-
-;Load the initial registers from the stack
-pop bx
-pop ax
-
-ret
diff --git a/src/ECHO.INC b/src/ECHO.INC
deleted file mode 100644
index 9a4900e..0000000
--- a/src/ECHO.INC
+++ /dev/null
@@ -1,21 +0,0 @@
-;Reads a string to the buffer and prints it.
-
-echo:
-
-;Read a string
-mov di, buffer
-mov al, 0xff
-mov ah, 0x3
-int 0x21
-
-;Check for an empty string
-cmp byte [buffer], 0x0
-je .done
-
-;Print the string
-mov si, buffer
-mov ah, 0x2
-int 0x21
-
-.done:
-ret
diff --git a/src/FILEIFY.INC b/src/FILEIFY.INC
deleted file mode 100644
index 28a6079..0000000
--- a/src/FILEIFY.INC
+++ /dev/null
@@ -1,124 +0,0 @@
-;Reads a string, checks if it is a valid 8.3 file name, converts it into FAT formatting, and prints it.
-
-fileify:
-
-;Read a string
-mov di, buffer
-mov al, 0xff
-mov ah, 0x3
-int 0x21
-
-;Set SI and DI
-mov si, buffer
-mov di, .file
-
-;Initialise the name with spaces
-mov cx, 0xb
-mov al, 0x20
-rep stosb
-sub di, 0xb
-
-;Initialise the length counter for the main part of the name
-mov bl, 0x8
-
-.nameloop:
-;Load a character
-lodsb
-;Check for a period
-cmp al, 0x2e
-je .initext
-;Check for everything else and convert to upper case
-call .checkconv
-jmp .nameloop
-
-.initext:
-;Set DI and initialise the length counter for the extension
-mov bl, 0x3
-mov di, .file+0x8
-
-.extloop:
-;Load a character
-lodsb
-;Check for a period
-push ax
-cmp al, 0x2e
-je .error
-pop ax
-;Check for everything else and convert to upper case
-call .checkconv
-jmp .extloop
-
-.error:
-pop ax
-mov si, .errormsg
-mov ah, 0x2
-int 0x21
-jmp .done
-
-.print:
-pop ax
-mov si, .file
-mov ah, 0x2
-int 0x21
-
-.done:
-ret
-
-.file times 0xc db 0x0
-
-.errormsg db "Invalid file name", 0x0
-
-.checkconv:
-
-;Check for the string end
-cmp al, 0x0
-je .print
-
-;Check for the length limit
-cmp bl, 0x0
-je .error
-
-;Check for invalid characters
-cmp al, 0x22
-je .error
-cmp al, 0x2a
-jl .contcheck1
-cmp al, 0x2c
-jg .contcheck1
-jmp .error
-.contcheck1:
-cmp al, 0x2f
-je .error
-cmp al, 0x3a
-jl .contcheck2
-cmp al, 0x3f
-jg .contcheck2
-jmp .error
-.contcheck2:
-cmp al, 0x5b
-jl .contcheck3
-cmp al, 0x5d
-jg .contcheck3
-jmp .error
-.contcheck3:
-cmp al, 0x7c
-je .error
-
-;Find and convert lower case letters to upper case
-;Check for lower case
-cmp al, 0x61
-jl .storech
-cmp al, 0x7a
-jg .storech
-;Convert lower to upper case
-sub al, 0x20
-
-.storech:
-
-;Store the character
-stosb
-
-;Increase the counter
-dec bl
-
-ret
diff --git a/src/HELLO.INC b/src/HELLO.ASM
similarity index 72%
rename from src/HELLO.INC
rename to src/HELLO.ASM
index 7e0c973..44f0ab6 100644
--- a/src/HELLO.INC
+++ b/src/HELLO.ASM
@@ -1,11 +1,11 @@
+CPU 8086
+ORG 0x2000
+
 ;Prints a hello world.
-
-hello:
-
 mov si, .hello
 mov ah, 0x2
 int 0x21
+int 0x20
 
-ret
-
+;Data
 .hello db "Hello world!", 0x0
diff --git a/src/HELP.INC b/src/HELP.INC
deleted file mode 100644
index c344478..0000000
--- a/src/HELP.INC
+++ /dev/null
@@ -1,11 +0,0 @@
-;Prints help.
-
-help:
-
-mov si, .help
-mov ah, 0x2
-int 0x21
-
-ret
-
-.help db "Input:", 0xd, 0xa, "  * Typing a character overwrites the cursor location.", 0xd, 0xa, "  * The erase (=tab) key erases the cursor location.", 0xd, 0xa, "  * The space and backspace keys move the cursor.", 0xd, 0xa, "Commands:", 0xd, 0xa, "  * echo: echoes its input.", 0xd, 0xa, "  * fileify: prints its input in FAT format if it is a valid filename.", 0xd, 0xa, "  * hello: a hello world program.", 0xd, 0xa, "  * help: you are reading it.", 0xd, 0xa, "  * keycode: echoes the BIOS code of a key.", 0x0
diff --git a/src/KEYCODE.INC b/src/KEYCODE.INC
deleted file mode 100644
index a529793..0000000
--- a/src/KEYCODE.INC
+++ /dev/null
@@ -1,89 +0,0 @@
-;Reads a keypress and prints its BIOS keycode.
-
-keycode:
-
-;Read a keypress
-mov ah, 0x0
-int 0x16
-
-;Store the keycode
-mov [.scan], ah
-mov [.ascii], al
-
-;Print the prefix
-mov si, .prefix
-mov ah, 0x0
-int 0x21
-
-;Convert the scancode to a hex string
-mov al, [.scan]
-mov di, .keycode
-call .byte2hex
-
-;Convert the ascii value to a hex string
-mov al, [.ascii]
-mov di, .keycode
-add di, 0x2
-call .byte2hex
-
-;Print the keycode
-mov si, .keycode
-mov ah, 0x2
-int 0x21
-
-ret
-
-.prefix db "0x", 0x0
-
-.scan db 0x0
-.ascii db 0x0
-
-.keycode times 0x5 db 0x0
-
-.byte2hex:
-
-;Store the initial registers in the stack
-push si
-push ax
-push bx
-push cx
-
-;Move the byte to AH
-mov ah, al
-
-;Set a key for the hex digits
-mov si, .key
-
-;Set a counter for the two hex digits
-mov cx, 0x2
-
-.loop:
-
-;Read a nibble
-rol ax, 0x1
-rol ax, 0x1
-rol ax, 0x1
-rol ax, 0x1
-mov bx, ax
-
-;Convert the nibble to a hex digit
-and bx, 0xf
-mov bl, [si + bx]
-
-;Store the hex digit
-mov [di], bl
-
-;Repeat
-inc di
-dec cx
-jnz .loop
-
-;Load the initial registers from the stack
-pop cx
-pop bx
-pop ax
-pop si
-
-ret
-
-.key db "0123456789abcdef"
diff --git a/src/LOADF.INC b/src/LOADF.INC
new file mode 100644
index 0000000..d5bb3a1
--- /dev/null
+++ b/src/LOADF.INC
@@ -0,0 +1,309 @@
+;Load a file named in SI as a string ending in a null to the offset BX and set AL to 0x0 if the load was succesful and 0x1 if there was an error.
+
+loadf:
+
+;Store the initial registers in the stack
+push ax
+push bx
+push cx
+push dx
+push si
+push di
+
+;Store the offset
+mov word [.pointer], bx
+
+;Set DI at .file and initialise it with spaces
+mov di, .file
+mov cx, 0xb
+mov al, 0x20
+rep stosb
+sub di, 0xb
+
+;Convert .file into FAT formatting
+
+;Initialise the length counter for the main part of the name
+mov bl, 0x8
+
+;Convert the main part of the file name
+.nameloop:
+;Load a character
+lodsb
+;Check for a period
+cmp al, 0x2e
+je .initext
+;Check for everything else and convert to upper case
+call .checkconv
+jmp .nameloop
+
+;Convert the extension
+.initext:
+;Set DI and initialise the length counter for the extension
+mov bl, 0x3
+mov di, .file+0x8
+.extloop:
+;Load a character
+lodsb
+;Check for a period
+push ax
+cmp al, 0x2e
+je .error
+pop ax
+;Check for everything else and convert to upper case
+call .checkconv
+jmp .extloop
+
+;Set the carry flag and print an error message if the file name is invalid
+.error:
+pop ax
+stc
+mov si, .errormsg
+mov ah, 0x2
+int 0x21
+jmp .done
+
+;Find and load the file
+
+.load:
+pop ax
+
+;Load the root
+;Set the source
+mov ah, 0x0
+mov al, [.fats]
+mul word [.sectorsperfat]
+add ax, [.bootsectors]
+push ax
+call .calcsource
+;Set the destination
+mov si, stack
+add si, 0x100
+mov bx, si
+;Set the size
+push dx
+mov ax, [.rootentries]
+mov dx, 0x20
+mul dx
+mov dx, 0x0
+div word [.sectorsize]
+pop dx
+push ax
+;Load
+mov ah, 0x2
+int 0x13
+
+;Search the root for the file entry
+;Set DI to the root
+mov di, stack
+add di, 0x100
+;Initialise the search loop
+mov cx, word [.rootentries]
+mov ax, 0x0
+.search:
+;Store CX in the stack
+push cx
+;Check for the file entry
+mov si, .file
+mov cx, 0xb
+rep cmpsb
+je .loadentry
+;Set DI to the next entry
+add ax, 0x20
+mov di, stack
+add di, 0x100
+add di, ax
+;Load CX from the stack
+pop cx
+loop .search
+
+;Set the carry flag and print an error message if the file is not found
+stc
+mov si, .errormsg
+mov ah, 0x2
+int 0x21
+jmp .clearstack
+
+;Load the file entry
+.loadentry:
+;Load CX from the stack
+pop cx
+;Store the first cluster
+mov ax, word [es:di+0xf]
+mov word [.cluster], ax
+;Set the source
+mov ax, 0x1
+call .calcsource
+;Set the destination
+mov di, stack
+add di, 0x100
+mov bx, di
+;Set the size
+mov ax, [.sectorsperfat]
+;Load
+mov ah, 0x2
+int 0x13
+
+;Load the file
+
+;Load a cluster
+.loadcluster:
+;Set the source
+pop cx
+pop bx
+mov ax, word [.cluster]
+sub ax, 0x2
+mul byte [.clustersize]
+add ax, bx
+add ax, cx
+push bx
+push cx
+call .calcsource
+;Set the destination
+mov bx, word [.pointer]
+;Set the size
+;mov al, 0x1
+mov al, [.clustersize]
+;Load
+mov ah, 0x2
+int 0x13
+
+;Calculate the next cluster
+mov ax, [.cluster]
+mov dx, 0x0
+mov bx, 0x3
+mul bx
+mov bx, 0x2
+div bx
+mov si, stack
+add si, 0x100
+add si, ax
+mov ax, word [ds:si]
+or dx, dx
+jz .even
+shr ax, 1
+shr ax, 1
+shr ax, 1
+shr ax, 1
+jmp .contcalc
+.even:
+and ax, 0xfff
+.contcalc:
+mov word [.cluster], ax
+cmp ax, 0xff8
+jge .clearcarry
+mov ax, [.sectorsize]
+mul word [.clustersize]
+add word [.pointer], ax
+jmp .loadcluster
+
+;Clear the carry flag if the load was succesful
+.clearcarry:
+clc
+
+;Clear left over values from the stack
+.clearstack:
+pop cx
+pop bx
+
+.done:
+
+;Load the initial registers from the stack
+pop di
+pop si
+pop dx
+pop cx
+pop bx
+pop ax
+
+;Set AL to 0x1 if there was an error and to 0x0 otherwise
+jc .setal
+mov al, 0x0
+iret
+.setal:
+mov al, 0x1
+iret
+
+;Data
+.file     times 0xb db 0x20
+.errormsg db "File not found", 0x0
+.cluster  dw 0x0
+.pointer  dw 0x0
+
+;These are temporary until i write something to load them from the disk itself
+.bootdrive       db 0x0
+.sectorsize      dw 0x200 ;bytes
+.clustersize     db 0x2 ;sectors
+.bootsectors     dw 0x1
+.fats            db 0x2
+.rootentries     dw 0x70
+.sectorsperfat   dw 0x2
+.sectorspertrack dw 0x9
+.sides           dw 0x2
+
+;Check the file name and convert to upper case
+.checkconv:
+;Check for the string end
+cmp al, 0x0
+je .load
+;Check for the length limit
+cmp bl, 0x0
+je .error
+;Check for invalid characters
+cmp al, 0x22
+je .error
+cmp al, 0x2a
+jl .contcheck1
+cmp al, 0x2c
+jg .contcheck1
+jmp .error
+.contcheck1:
+cmp al, 0x2f
+je .error
+cmp al, 0x3a
+jl .contcheck2
+cmp al, 0x3f
+jg .contcheck2
+jmp .error
+.contcheck2:
+cmp al, 0x5b
+jl .contcheck3
+cmp al, 0x5d
+jg .contcheck3
+jmp .error
+.contcheck3:
+cmp al, 0x7c
+je .error
+;Check for lower case
+cmp al, 0x61
+jl .storech
+cmp al, 0x7a
+jg .storech
+;Convert lower to upper case
+sub al, 0x20
+.storech:
+;Store the character
+stosb
+;Increase the counter
+dec bl
+ret
+
+;Calculate the source arguments for loading data from the disk
+.calcsource:
+push ax
+push bx
+mov bx, ax
+mov dx, 0x0
+div word [.sectorspertrack]
+add dl, 0x1
+mov cl, dl
+mov ax, bx
+mov dx, 0x0
+div word [.sectorspertrack]
+mov dx, 0x0
+div word [.sides]
+mov dh, dl
+mov ch, al
+pop bx
+pop ax
+mov dl, byte [.bootdrive]
+ret
diff --git a/src/NEWLINE.INC b/src/NEWLINE.INC
deleted file mode 100644
index bc88c22..0000000
--- a/src/NEWLINE.INC
+++ /dev/null
@@ -1,18 +0,0 @@
-;Prints a newline
-
-newline:
-
-;Store the initial registers in the stack
-push si
-
-;Print the newline
-mov si, .newline
-mov ah, 0x0
-int 0x21
-
-;Load the initial registers from the stack
-pop si
-
-ret
-
-.newline db 0xd, 0xa, 0x0
diff --git a/src/PRINTLN.INC b/src/PRINTLN.INC
index 399409b..354a9c9 100644
--- a/src/PRINTLN.INC
+++ b/src/PRINTLN.INC
@@ -1,4 +1,4 @@
-;Prints a string from SI until a null, followed by a newline.
+;Print a string ending in a null from SI followed by a CRLF.
 
 println:
 
@@ -6,7 +6,7 @@ println:
 mov ah, 0x0
 int 0x21
 
-;Print a newline
-call newline
+;Print a CRLF
+call printcrlf
 
 iret
diff --git a/src/PRINTSTR.INC b/src/PRINTSTR.INC
index b21eead..a49fdfb 100644
--- a/src/PRINTSTR.INC
+++ b/src/PRINTSTR.INC
@@ -1,4 +1,4 @@
-;Prints a string from SI until a null.
+;Print a string ending in a null from SI.
 
 printstr:
 
diff --git a/src/READLN.INC b/src/READLN.INC
index cbb0b7b..06747b7 100644
--- a/src/READLN.INC
+++ b/src/READLN.INC
@@ -1,4 +1,4 @@
-;Reads a string of at most AL characters to DI until a return and prints a newline.
+;Read a string ending in null of at most AL characters to DI until a return and print a CRLF.
 
 readln:
 
@@ -6,7 +6,7 @@ readln:
 mov ah, 0x1
 int 0x21
 
-;Print a newline
-call newline
+;Print a CRLF
+call printcrlf
 
 iret
diff --git a/src/READSTR.INC b/src/READSTR.INC
index d826923..75cb76d 100644
--- a/src/READSTR.INC
+++ b/src/READSTR.INC
@@ -1,4 +1,4 @@
-;Reads a string of at most AL characters to DI until a return.
+;Read a string ending in a null of at most AL characters to DI until a return.
 
 readstr:
 
diff --git a/src/SYSTEM.ASM b/src/SYSTEM.ASM
index 299103b..f1f8fe4 100644
--- a/src/SYSTEM.ASM
+++ b/src/SYSTEM.ASM
@@ -4,8 +4,10 @@ ORG 0x500
 jmp start
 
 ;Interrupt handler
+;Return to the shell
 int0x20:
 jmp shell
+;Input and output
 int0x21:
 cmp ah, 0x0
 je printstr
@@ -16,8 +18,11 @@ je println
 cmp ah, 0x3
 je readln
 iret
+;Disk operations
 int0x22:
-;To do: loading and saving files
+cmp ah, 0x0
+je loadf
+;To do: savef
 iret
 
 ;System calls
@@ -25,17 +30,7 @@ iret
 %include "READSTR.INC"
 %include "PRINTLN.INC"
 %include "READLN.INC"
-
-;Internal calls
-%include "CMPSTR.INC"
-%include "NEWLINE.INC"
-
-;Commands
-%include "ECHO.INC"
-%include "FILEIFY.INC"
-%include "HELLO.INC"
-%include "HELP.INC"
-%include "KEYCODE.INC"
+%include "LOADF.INC"
 
 start:
 
@@ -46,20 +41,19 @@ mov sp, stack
 add sp, 0x100
 sti
 ;Set up the interrupt vectors
-;Interrupt 0x20
+;Interrupt 0x20 offset
 mov ax, int0x20
 mov [0x80], ax
-mov ax, 0x0
-mov [0x82], ax
-;Interrupt 0x21
+;Interrupt 0x21 offset
 mov ax, int0x21
 mov [0x84], ax
-mov ax, 0x0
-mov [0x86], ax
-;Interrupt 0x22
+;Interrupt 0x22 offset
 mov ax, int0x22
 mov [0x88], ax
+;Segments
 mov ax, 0x0
+mov [0x82], ax
+mov [0x86], ax
 mov [0x8a], ax
 
 ;Print a welcome message
@@ -69,86 +63,65 @@ int 0x21
 
 shell:
 
+;Re-set up the stack
+cli
+mov sp, stack
+add sp, 0x100
+sti
+
 ;Prompt for and read a command
 ;Print a prompt
 mov si, prompt
 mov ah, 0x0
 int 0x21
-;Read a command
-mov di, buffer
+;Read
+mov di, input
 mov al, 0xff
 mov ah, 0x3
 int 0x21
 
-;Identify and execute the command
-exec:
-;Check for no command
-cmp byte [buffer], 0x0
-je shell
-.echo:
-;Check
-mov si, buffer
-mov di, cmd.echo
-call cmpstr
-jnc .fileify
+;Load an execute the program
+;Load
+mov bx, 0x2000
+mov si, input
+mov ah, 0x0
+int 0x22
+;Check for errors
+cmp al, 0x1
+je error
 ;Execute
-call echo
-jmp shell
-.fileify:
-;Check
-mov si, buffer
-mov di, cmd.fileify
-call cmpstr
-jnc .hello
-;Execute
-call fileify
-jmp shell
-.hello:
-;Check
-mov si, buffer
-mov di, cmd.hello
-call cmpstr
-jnc .help
-;Execute
-call hello
-jmp shell
-.help:
-;Check
-mov si, buffer
-mov di, cmd.help
-call cmpstr
-jnc .keycode
-;Execute
-call help
-jmp shell
-.keycode:
-;Check
-mov si, buffer
-mov di, cmd.keycode
-call cmpstr
-jnc .error
-;Execute
-call keycode
-jmp shell
-.error:
+jmp 0x2000
+
+;Print an error message and return to the shell
+error:
+mov bh, 0x0
+mov ah, 0x3
+int 0x10
+dec dh
+mov ah, 0x2
+int 0x10
 mov si, errormsg
 mov ah, 0x2
 int 0x21
 jmp shell
 
+;Data
 welcomemsg db 0xd, 0xa, "Welcome to EttinOS!", 0xd, 0xa, 0x0
+prompt     db "> ", 0x0
+errormsg   db "Unknown command", 0x0
+input      times 0xff db 0x0
+crlf       db 0xd, 0xa, 0x0
 
-prompt db "> ", 0x0
-
-cmd:
-.echo    db "echo", 0x0
-.fileify  db "fileify", 0x0
-.hello   db "hello", 0x0
-.help    db "help", 0x0
-.keycode db "keycode", 0x0
-
-errormsg db "Unknown command", 0x0
-
-buffer times 0xff db 0x0
+;Print a CRLF
+printcrlf:
+;Store the initial registers in the stack
+push si
+;Print the CRLF
+mov si, crlf
+mov ah, 0x0
+int 0x21
+;Load the initial registers from the stack
+pop si
+ret
 
 stack: