LICENSE.md

@@ -1,21 +0,0 @@
-MIT License
-
-Copyright (c) 2016 
-
-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.

Makefile

@@ -1,16 +1,9 @@
-UNAME := $(shell uname)
-ifeq ($(UNAME), Darwin)
-	STAT := gstat
-else
-	STAT := stat
-endif
-
 all: tetros.img
 
 tetros.img: tetros.asm Makefile
 	nasm -d DEBUG -f bin tetros.asm -o tetros.img
-	@echo "size is" `$(STAT) -c "%s" tetros.img`
-	@if [ `$(STAT) -c "%s" tetros.img` -gt 446 ]; then \
+	@echo "size is" `stat -c "%s" tetros.img`
+	@if [ `stat -c "%s" tetros.img` -gt 446 ]; then \
 		bash -c 'echo -e "\e[91mOutput exceeded size of 446 bytes.\e[0m"'; \
 		rm -f tetros.img; exit 1; fi
 	nasm -f bin tetros.asm -o tetros.img

README.md

@@ -1,29 +1,17 @@
 # TetrOS
-TetrOS is a small *feature rich* Tetris clone which is written in Assembly. It fits completely into a 512 byte boot sector as it requires only 446 bytes (which is the maximum allowed size of the first stage boot loader in the master boot record (MBR) of a drive) and is executed during the boot sequence before any operating system is loaded. Actually, it does not need any existing operating system. TetrOS *is* an operating system, hence the suffix OS in its name.
+TetrOS is a small *feature rich* Tetris clone which is written in Assembly.
+It fits completely into a 512 byte boot sector and is executed during the
+boot sequence before any operating system is loaded. It does not need any
+existing operating system. TetrOS is its own operating system, hence the suffix
+OS in its name.
 
-Video that shows TetrOS in action:
+This is how it looks like:
 
-[![TetrOS - Teris in 512 byte boot sector](http://img.youtube.com/vi/Hl7M7f-Hh78/0.jpg)](https://youtu.be/Hl7M7f-Hh78)
+![TetrOS - Tetris in 512 byte boot sector](https://github.com/daniel-e/mbr_tetris/blob/master/tetros_tetris_screenshot.png)
 
 And this is the complete machine code:
 
-![TetrOS - Machine code](https://github.com/daniel-e/mbr_tetris/blob/master/screenshots/code.png)
-
-## Running TetrOS
-
-There are two options to run TetrOS. Either in an emulator like qemu or via an installation of TetrOS in the boot sector of a real disk, USB stick or some other media.
-
-### Running via qemu
-
-Simply run `make run`. This will execute qemu with the right parameters to run TetrOS. If you're using Ubuntu and qemu is not intalled on your system you can install it via `sudo apt-get install qemu`.
-
-### Running via an USB stick
-
-First, copy the image to an USB stick. For example, if your USB stick is on `/dev/sde` use the following command to overwrite the first sector of the USB stick with the TetrOS image:
-
-`sudo dd if=tetros.img of=/dev/sde`
-
-After that you should be able to boot the stick to play TetrOS.
+![TetrOS - Machine code](https://github.com/daniel-e/mbr_tetris/blob/master/code.png)
 
 ## Features
 * Each brick shape has a unique color.
@@ -33,7 +21,7 @@ After that you should be able to boot the stick to play TetrOS.
 * Down arrow to drop a brick.
 * Game over detection. It stops if a new brick could not be placed.
 * Selects the next brick at random via a linear congruential generator.
-* Nice playing field.
+* Shows a nice playing field.
 
 ## Features missing due to size limits
 * Scores and highscores.
@@ -42,21 +30,7 @@ After that you should be able to boot the stick to play TetrOS.
 * Show next brick.
 * Increase speed.
 
-## Compiling the sources
-
-The repository already contains an image which you can use for testing. However, if you want to compile the image from the sources you need nasm, a general prupose x86 assembler to be installed on your system. On Ubuntu you can can install it via the command `sudo apt-get install nasm`. On macOS you will need [homebrew](http://brew.sh/) to install `nasm` and `binutils`.
-
-If `nasm` is installed you can compile the sources by executing `make`. This will create the image `tetros.img`. After that you can run the image via qemu or you can copy the image via `dd` on an USB disk or a disk (see above).
-
-I have tested it with nasm 2.11.08 on Ubuntu 16.04.
-
 ## Similar projects
 * https://github.com/dbittman/bootris
 * https://github.com/Shikhin/tetranglix
 * http://olivier.poudade.free.fr/src/BootChess.asm
-* https://github.com/programble/tetrasm - Tetris for x86 in NASM but which does not fit into the boot sector.
-
-## Acknowledgements
-I would like to thank the following persons for contributing to TetrOS.
-* [DraftYeti5608](https://github.com/DraftYeti5608)
-* [Ivoah](https://github.com/Ivoah)

tetros.asm

@@ -90,7 +90,7 @@ new_brick:
 	mov byte [delay], 100            ; 3 * 100 = 300ms
 	select_brick                     ; returns the selected brick in AL
 	mov dx, start_row_col            ; start at row 4 and col 38
-lp:
+loop:
 	call check_collision
 	jne $                            ; collision -> game over
 	call print_brick
@@ -154,7 +154,7 @@ no_key:
 	call clear_brick
 	inc dh                       ; increase row
 	call check_collision
-	je lp                        ; no collision
+	je loop                      ; no collision
 	dec dh
 	call print_brick
 	call check_filled
@@ -253,7 +253,7 @@ check_collision_main:            ; DI = 1 -> check, 0 -> print
 cc:
 	push cx
 	mov cl, 4
-zz:
+dd:
 	test ah, 10000000b
 	jz is_zero
 
@@ -278,7 +278,7 @@ is_zero_a:
 is_zero:
 	shl ax, 1                    ; move to next bit in brick mask
 	inc dx                       ; move to next column
-	loop zz
+	loop dd
 	sub dl, 4                    ; reset column
 	inc dh                       ; move to next row
 	pop cx