Casio's fx-7000G was the first graphing calculator. I had one and in the late 80s and then the much nicer looking fx-7700g in the early 90s. FX-7000G had 422 by

Casio's fx-7000G was the first graphing calculator. I had one and in the late 80s and then the much nicer looking fx-7700g in the early 90s. FX-7000G had 422 bytes of RAM (one BASIC token used a byte) and the 7700 had about ten times as much. I was able to program it to draw decent fractals; Mandelbrot set took about 1/2 an hour, Martin Fractal, Sierpinski Triangle, etc. Much more fun than GCSE and A-Level Maths. I managed a few simple games but there was no way to read keyboard input without pausing execution so they had to be turn based. The best game was probably a simple reaction timer which waited a random time then told you to press AC, and when re-run let you know your approximate time for the last run. I also used the memory for storing my timetable for the week and and notes for tests, but I was always too nervous to use the stored test data. Also the laborious effort of entering in text had embedded the small amount of text into my memory well.