I also started with a TI-99/4A, received as a gift in 1983. I added a peripheral expansion box with UCSD pSystem and UCSD Pascal, a serial card, a disk drive and 32K (if I recall correctly) of RAM. I learned how to program BASIC, TI Assembly language and UCSD Pascal on that thing. After getting my first programming job in 1984, I bought a Sanyo MBC-555 with 256K or RAM, 2 360K DSDD floppies and a video card that allowed running Lotus 1-2-3. That baby ran DOS 2.11 and lasted until the mid 90s.