8086 ASM DOSBox Examples

A set of runnable 8086 ASM Programs, taken from the CPE 022 — Computer Architecture and Organization as Exercises and Activity (Deliverables).

Welcome

This repository contains all of my activities and exercises taken from one of my courses (see the names on the sub title above). It was dumped to ensure that further review from this field and scope is reviewable without problems.

In short, I want to dump my deliverables somewhere open so that other fellow students who take up this course can find learning materials (not a cheating material!!!) for them to learn. If you ever get doubt at learning at this, then try looking at this repository where each .ASM has its comments (my insights).

Pre-requisites

The following list is a set of things you need to get up and running.

1. An IDE or Text Editor (I'm using Visual Studio Code)
2. DOSBox
3. TASM
4. TLINK

Note

There's no indicator which version is better or optimal. Please follow the instructions of your professor.

Running

Here's my snippet of what I have in my DOSBox Startup Configuration.

MOUNT <ANY_DRIVE_LETTER> <FOLDER>
<ANY_DRIVE_LETTER>:

TASM <PROGRAM_NAME_WO_EXTENSION>
TLINK /T <PROGRAM_NAME_WO_EXTENSION>
<PROGRAM_NAME_WO_EXTENSION>

Reminder

1. The first 2 is optional. The last 3 is required.
2. It is pretty obvious that you should change the contents inside "<>" but without "<>" literally.
3. Keep in mind that, this is my way of launching my ASM programs, because, I mainly debug them and once they are okay. I'm gonna close it and call it a day.

Filenames and Output

The following is a list of filenames along with it's description and their output. It will be long list, please check the media folder for the overview of those picture. Or click the images per row to see the exact output.

#	Filename (.asm)	Require /T (*)	Description	Output
1	ADD_NUM	Yes	(Adding Numbers) Adds 2 single-digit numbers and display them properly. (In-Equation Form)
2	ATTRSCRL	No	(*Attribute Render with Scrolling) Scroll then Render a 3-Column Color, Green-Red-Blue respectively.
3	CHAR_POS	No	(Character Positioning via Manipulation) Get certain character index and move it somewhere from the string.
4	CMP_JMP	No	(Compare then Jump!) Compare and jump from one label to another based on input.
5	DSTROUT	No	(Double String Output) Displays a string from the input twice with delimiter handling via pointer.
6	GL_CB	No	(Google Cardboard Logo) A Logo Design of Google Cardboard in 8-bit Terminal.
7	GUESS_N	No	(Guess the Number!) Guess the number (5) with indicators of making the user input higher or lower.
8	LYMC	No	(Light Blue-Yellow-Magenta-Cyan Column) Renders 4-Column Colors with Identification String.
9	SH_USERN	No	(Show Username after Input) Show's username after asking for the name with delimiter modification.
10	SMP_ATTR	No	(Sample of Screen Attribute Modification) Shows a sample of blinking letters with background and foreground colors.
11	STCK_REC	No	(Stacked Rectangles) Just 3 rectangles, stacked together. Rendered in reverse.
12	STR_POS	No	(String Positioning) Displays a string in the column-centric of the 80x80 terminal.
13	STRMANIP	No	(String Manipulation) Displays a string in reversed with extreme manipulation.
14	SUB_NUM	Yes	(Subtract Numbers) Subtracts 2 single-digit numbers with string output. (Non-Equation Output)
15	TRGB	No	T-Structure in Red and Green (Left) + Blue (Right) for Spacing.
16	TRIA	No	(Half-Triangle) Rendered with Bare-Minimum Loops.

Note(s)

1. The filenames are 8-letters long. Anything more than 8 will make the DOSBOX complain that it can't find it.(2) asd
2. Most of the operations such as Adding and Subtracting a Number may require the use of /T when linking with TLINK.exe. Please double check if TLINK is complaining about the stack being non-existent or otherwise.
3. With that being said, please try /T if the program won't run. The evaluation of needing /T is purely based from assumption without running them and carefully evaluating it.
4. There are atleast 1-2 activities that didn't make it to the open-source. This is because those activities are: (a) too basic, (b) potentially renders someone unable to learn. and, (c) too complex to be provided and taken away. I have this one activity that has the capacity to drain my dignity for about 12 hours, I'll never forget that.

Why would I do this?

When there's a course that can't be taught professionally (in the means of teaching them with further knowledge about it), I would go initiate self-learning mode then proceed to ignore their teachings (they teach what's the basics and then proceed to have us learn the hard ropes because why not, it's a money grab anyway).

Disclosure

Whenever you clone this repository and take action on any part of this material, you are putting yourself in a responsibility where you can't blame and risk someone else (like me) for getting yourself caught cheating or otherwise.

I only provide materials in a fashion where I want to distribute them because I used other resources. If these materials are the exact thing that shows in your deliverables, please learn instead of copying them straight up from someone else.

With the fact of typical students stealing, please if possible, credit. There would be no issues whenever you do it or now either way; just give some appreciation at least.

Resources Used

The following links are a set of redirections to certain PDFs or articles that contain information on what you are doing. Keep in note that some of these links may also cover DEBUGX (which I didn't dump because I don't have them saved locally, they were done in runtime and didn't intend to save them.)

1. Some TASM Instruction Set Info: http://www.husseinsspace.com/teaching/udw/1996/asmnotes/chaptwo.htm
2. Service Interrupts Sys Calls: http://spike.scu.edu.au/~barry/interrupts.html
3. Some Intro to Assembly: https://www.tutorialspoint.com/assembly_programming/assembly_tutorial.pdf
4. Regarding About 4C00H Termination: https://www.quora.com/MOV-AX-4C00H-what-does-this-instruction-mean-in-a-microprocessor
5. Flag Registers in 8085 and 8086: https://www.geeksforgeeks.org/flag-register-8085-microprocessor/ | https://www.geeksforgeeks.org/flag-register-8086-microprocessor/
6. Arithmetic Flags and Instruction: https://service.scs.carleton.ca/sivarama/asm_book_web/Student_copies/ch6_arithmetic.pdf | http://www.ee.nmt.edu/~rison/ee308_spr02/supp/020123.pdf
7. Assembly Registers: https://www.tutorialspoint.com/assembly_programming/assembly_registers.htm | https://www.csie.ntu.edu.tw/~acpang/course/asm_2004/slides/chapt_07_PartIISolve.pdf | https://www.tutorialspoint.com/assembly_programming/assembly_arithmetic_instructions.htm
8. Registers and Executions: http://www.godevtool.com/GoasmHelp/newass.htm
9. DEBUG Instructions: https://www.slideshare.net/defrimnc/debug-tutorial | https://montcs.bloomu.edu/Information/LowLevel/DOS-Debug.html
10. ASM 8086 Cheatsheet: https://cheatography.com/mika56/cheat-sheets/asm-8086/
11. About Brackets as Dereference of Address: https://stackoverflow.com/questions/2030366/what-do-the-brackets-mean-in-x86-asm | https://stackoverflow.com/questions/39474332/assembly-difference-between-var-and-var | Exactly: https://stackoverflow.com/a/39474679/5353223
12. About DUP for Custom Declaration of Bytes of Space, Page 15: https://www2.southeastern.edu/Academics/Faculty/kyang/2009/Fall/CMPS293&290/ClassNotes/CMPS293&290ClassNotesChap03.pdf
13. Understanding the use of "MOV AX, 0B800H": https://www.tek-tips.com/viewthread.cfm?qid=614518
14. Understanding the use of "ORG 100H": https://stackoverflow.com/questions/13321808/how-does-assembler-process-org-100h-directive
15. What is @data in ASM (cont.): https://stackoverflow.com/questions/4928538/what-does-the-data-directive-mean-in-masm | Proof: https://stackoverflow.com/questions/5330306/when-will-the-code-under-data-segment-execute-in-this-code | Work: https://stackoverflow.com/a/47002757/5353223
16. Entering String Snippet: https://stackoverflow.com/a/29517960/5353223
17. Looping Introduction: https://stackoverflow.com/a/10358699/5353223
18. Supported Interrupts by Emulators in 8086 Architecture: https://www.gabrielececchetti.it/Teaching/CalcolatoriElettronici/Docs/i8086_and_DOS_interrupts.pdf

Credits

I would like to thank all of the authors that has a question that exists in the internet, people who provides pdfs and articles without shutting their servers down, extensions who extend the capabilities of my text editor, providers of TASM, DEBUGX and TLINK compiled programs, and other people who became the part of my self-learning experience of this course. Some links provided below are the once I can honorly mention because of my utilization to their programs / extensions / etc:

1. Assembly 8086 (TASM) by Roncho
2. Neovim
3. Vim Extension by vscodevim
4. DOSBox Emulator
5. Visual Studio Code

Thank you for reaching this far. I appreciate you for taking an interest to my dumped contents.