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02-01-2017 - Assembly_is_Too_High-Level_-_Signed_Displacements

An exploration of some ambiguities that signed numbers can introduce to your assembler, what your assembler will choose, and how you can choose anything you want.

08-29-2016 - Boot_Sector_Graphical_Programming_-_Tutorial

A quickstart guide to making some boot sector games. This guide assumes you know some x86 basics. From there, you learn how to boot a skeleton with a stack, video memory, keyboard control, timing loops, colors, and random.

05-11-2016 - CactusCon_Slides_-_Machining_-_A_Love_Story

These are the slides (with slide notes) that I gave at Cactus Con in 2016. It's about my unrealized childhood dream of programming in machine code directly (unrealized as a child).

02-13-2016 - Assembly_is_Too_High_Level_-_Repetition_of_REP_Instructions_That_Don't_Repeat_Anything

Abuse of the REP prefix for instructions that it doesn't apply to.

01-24-2016 - Assembly_is_Too_High_Level_-_Why_ESP_doesn't_scale_-_But_EBP_can_still_Base

Not all registers can be scaled (multiplied by 1, 2, 4, & 8), read on for details of why this is a thing due to machine encoding.

01-24-2016 - Assembly_is_Too_High_Level_-_Redundant_Bit_commands

Some insctructions have the operand of immediate 1 hardcoded, but you can still use 1 as an operand value for the variale immediate data.

01-19-2016 - Assembly_is_Too_High_Level_-_SIB_Doubles

Some abuse and redundancy discussion involving scaling by 2 and other edge cases with the SIB table.

01-11-2016 - Assembly_is_Too_High_Level_-_Load_InEffective_Address

LEA is encoded with the MODR/M byte, even though that would allow for some invalid encodings. Read on if you want to explore what happens when we do this.

01-05-2016 - Assembly_is_Too_High-Level_-_TEST_r32,_r-m32,_exists_in_assembly,_but_not_the_machine

A test instruction that is valid in assembly language, but has no machine encoding. The assembler uses something logically equivalent when encoded.

12-30-2015 - Assembly_is_Too_High-Level_-_BSWAPin_16-bit_Registers

It is invalid assembly to BSWAP 16-bit registers, read on to find out what happens when we try to do it anyway.

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