Deathshadow's Madness
Madness and you, perfect together

On this site you will find various libraries and programs I have written relating to legacy computing, as well as reviews and information about older retro-computing projects. Everything here is released to the public domain, meaning free to use so long as you credit the original author, Jason M. Knight. A backlink to this website would also be greatly appreciated.

10 Nov 2017 - Why I use BCD for scorekeeping in 8088 games

For a while I’ve gotten a LOT of questions about why the C64 version, and my upcoming ASM version of Paku Paku tracks scores in BCD – Binary Coded Decimal. The simple fact is that it is WAY faster even with the overhead of the long score additions. Sure, each score takes 8 bytes (I display a fake ‘0’ after since all score values are multiples of ten, 9 digits is overkill) instead of four...

But the simple fact is that whilst yes, adding a value to the score takes eight additions with AAA (ascii adjust for addition), that is still WAY faster than the multiple divides (16 in total) needed to turn a 32 bit integer into ASCII or even just BCD -- and you'd need it in one or the other to output to the screen! You basically NEED unpacked (aka 8 bits per digit) binary coded decimal or something like it to handle display numeric output in a way Joe Sixpack and Susie Sunshine can digest. "normal people" aren't going to be happy if you display your scores in a game in hexadecimal!

06 Nov 2017 - Gotta Get Back in Time

For a while I've been laughing at people who thought the old site skin looked like something out of the 1990's, which quite clearly illustrated said folks had never been online in the 1990's... so here's a change for you guys. Since I'm retiring the now eight year old codebase that was sitting under this site, I figured I'd give it a new skin.

AMC Eagle

Welcome to 1985! ... and sorry, the DeLorean is a bit too stylish AND non-utilitarian for this.

Not entirely retro though, I was planning on going with a period accurate webfont to match, but it compromised legibility a bit too much. Likewise I was going to limit myself to the 16 CGA colours, but that too led to a few contrast issues. As such this is a hybrid. Tahoma font which looks kind of nice (almost like a whole different font) once you give it the line-height and spacing it deserves, legible colour contrasts across the board whilst maintaining the overall "feel" of classic DOS text.

You remember TEXT, right? That thing the Twitter generation TLDR mouth breathers get their panties in a wad over going "wah, wah, I don't wanna have to READ!" like a petulant orange cheeto-fingered commander in half-tweet?

16 Jul 2017 - Model F My ARSE

A friend shared an article off NPR's "All Tech Considered" section that really raised the hackles on my hackles. Normally I don't use this area of the site for blogging, but given what total BULLSHIT the subject of said article is -- mated to the fact that MOST places seem to stamp out any dissension or post calling it out for being bull -- I'm decidedly making an exception!

Simply put, we have some joker claiming he's "bringing back" the Model F...

Their site is here:

First off they make a version without the numeric keypad or the function keys -- fine, I guess for fringe whackos who put form over function having the OPTION isn't the end of the world, but seriously, LOOK at the bloody LAYOUT of even the 'proper' version in terms of JUST the core key area (ignore the keypad area):

What the **** makes this a model F?!?

That's a Model M layout!

About Me


This site was created by Jason M. Knight, a retired software engineer with nearly four decades experience in electronics, software development, and graphic arts - not to mention a wide range of hobbies including Saxophone, EWI, programming, carving, drawing, and just being a general pain in the ass on web development forums ripping new holes for the nimrods who think HTML 5, JQuery or Dreamweaver are actually good things.

My Other Sites


Featuring articles, tutorials, and rants about web development. The focus of the site on minimalist semantic markup, separation of presentation from content, graceful degradation, and accessible design.


A small lightweight JavaScript library designed to promote good practices without becoming a bloated mess like most of the "frameworks" out there. Simplifies common cross-browser tasks, aids in navigating and manipulating the DOM, and polyfills bits of ECMAScript 5 that are not to be found in any version of IE.


An informational website about the Akai EWI - Electronic Wind Instrument.