The most popular graphing calculators were of course the TI-83/84 Plus, which every American student for the past decade and a half has probably seen. Needless to say, this is the very definition of a constrained environment.
Generally, 32KB of RAM, and on the 83+ and later, anywhere from 100KB to 2MB of flash storage (“archive”).A link port which (ab)used the 2.5mm headphone jack connector.The latest models finally have higher resolution color screens.) 96圆4 black and white LCD (a few models had a larger screen but this was by far the most common.z80 processor usually clocked at 8 or 10MHz-and note that the z80 can only retire one instruction every 4 cycles.They were quite nice 45 years ago when they were released!Īll TI calculators generally had similar low-end specs: You might have heard of the z80-it was an improved version of the Intel 8080 developed by Zilog. Throughout the 90s and 2000s, TI released a succession of z80-based graphing calculators. I do plan to continue the articles I’ve started! Thanks to everyone who has emailed to check on me-and I apologize for not being super responsive over email. In the space of a year I’ve gotten a new job, bought a house, moved. Wow, it’s been a while since I’ve written anything.
This is not a coincidence because nothing is ever a coincidence with xkcd.
There are also 768 bytes in the RAM buffer used to hold TI display bitmaps. I’ll take you through some of the highlights of Texas Instruments calculator hacking done over the past two and a half decades, along with an explanation of why these projects are so technically impressive. True to my interests, it’s all deeply embedded, pushing the limits of platforms that were obsolete when they were released. There was in fact a thriving scene of hackers who had bent these calculators to their will, writing games, math software, and more generally hacking on the platform just for the sake of it. You may be surprised to learn that some of these people didn’t exist totally in a vaccuum. The one who could put games on your graphing calculator. Finishing this set of 9 missions would get back to 6-space-missions.In the mid-to-late 2000s, you either knew, or were, that kid in grade school. The first 9 missions are using 6 spaces for the invader, but the 9 missions after the first 9 missions would have 1 space less (i.e. Missions get faster and faster but after finishing 9 missions the game speed would slow down again.
If the invaders killed in the mission accumulates to be multiple of 10, a special saucer will appear (represented by an n). If all 30 missiles are fired but there are still remaining invaders the game is over immediately too. The digit second from the left on the screen is the number of lives remaining in that mission.Įvery mission has 16 invaders coming and you got 30 missiles to kill them. The game is over if you lose 3 lives in the same mission. If any invaders successfully land on your base before they are killed you lose a life. Invaders appears from the right side of the screen flying leftwards gradually. This left most digit represents the type of invader you can kill if you press the fire button. The aim button is for aiming the missile, pressing it would make the left most digit on the screen to cycle through 0 to 9 and then n and then 0 again. The left button is aim and the right button is fire. It was implemented on a pocket calculator that just has an 8 digit LCD panel and each digit is just a 7-segment-LCD with 2 buttons. It is about there are invaders from space represented by digits attacking our missile base. The game is actually called "Digit invader".