Thursday, May 15, 2014

Arithmetic Games Set 1: a Peek into One of the First-Ever IBM PC Games

For whatever reason, I'm a sucker for "firsts", and the earliest games on the IBM PC platform hold special interest for me, with an extra touch of morbid curiosity reserved for stuff like BASIC games (and for IBM's own offerings). Thus, I was quite intrigued when I recently came across something that answers all these criteria: a disk dump of Arithmetic Games Set 1, developed by Science Research Associates, Inc. and published by IBM.

There was zero coverage of this particular game online, even at the usual suspect places, but (to quote a certain bunch of mean, green, caterpillar-like alien overlords) you will note that this oversight has been rectified: I added a MobyGames entry for it. This post won't cover AGS1's qualities as a game (or as a pair of games), so if you fancy some screenshots and a general description, head on over there.

What got my attention first was the time-frame. Have a look at this (and keep in mind that the IBM PC was officially introduced on August 12, 1981):

Tuesday, May 13, 2014

Shamus Keyboard Woes Explained

My previous post contains copious amounts of whinging about the keyboard controls in this game, but as it turns out, the issue isn't with the game as such - it's about the environment.  Recently it was pointed out to me that Shamus uses a buffered input routine (it isn't the BIOS INT 9 handler, but a custom handler that similarly buffers keystrokes), and as such, it's sensitive to the typematic rate and delay set for the keyboard.

For the unfamiliar, these parameters control how long a key must be held down before a repeated keypress is signaled, and then the rate at which the keypress is repeated.  Older PC/XT-class machines (which is what this game was targeted at) always booted up with a default delay of 500ms and repeat rate of 10 characters per second; this is what the game assumes, and under these conditions keyboard control isn't a problem.