I would like to save and load BASIC programs with my TI-99/4A. The TI-99/4A can be connected to a cassette recorder for this purpose. Buying a cassette recorder and cassette tapes seems unnecessary by modern means. Is it possible to use the official TI Dual Cassette adapter to load and save data to a smartphone or other modern digital recorder/playback device?
Any cassette tape system which can utilize a standard cassette tape recorder can be plugged into any audio device, with sufficient quality, and will work.
You can record saved files with any audio recording app and load it back in by playing it back. I know this is regularly done on the Apple II, Sinclair ZX Spectrum, and Tandy Color Computer systems, and surely many others.
This cannot be done (at least easily) on Commodore or Atari 8-bit computer systems because the cassette tape recorder has special circuitry which makes it incompatible with standard cassette tape recorders or other audio devices.
I have tried to save or load from a smartphone and PC. These don't record well. However the audio file from tape may be processed on PC. Audiotap and CS1er are examples of software for the TI. I have tried successfully to use an MP3 player (including through Bluetooth) to play wav files. A repossitory for wav files is at whtech: https://computerarchive.org/files/mirror/ftp.whtech.com/Cassettes/ Good luck !