- Vintage TI85, TI86, TI92 "Expander II"
- 07 Jul 2020 04:08:55 pm Permalink
I am looking for information on "Expanders", which were built to allow TI85, TI86, TI92 users to store programs & other data externally in an era before USB Flash drives, I built one for my TI85 & TI86 in 1999 / 2000, the Expander II was only capable of storing up to 1MB! On an Atmel EEPROM IC, it also required an on calc program to facilitate it's function, it was a voluntary project in an Industrial Electronics course, I had to etch the PCB myself & mail ordered a programmed microcontroller needed to read / write to the EEPROM IC & communicate with the calc. I am wondering if there is documentation on, particularly, the "Expander II" / "Expander 2", schematics, microcontroller code & other docs. I'm wanting to build another "Expander II" as a vintage hardware project. I own a PICKit3 programmer / debugger so programming a microcontroller is trivial, likely would use a PIC16F887 or PIC16F877a Microcontroller, I have DOZENS of them on hand.