I still have a 300 bps acoustic coupler (the modem where you put the phone handset into it). I used that on a TI Professional Portable. This had 256k of RAM, 2 5¼" floppies, a 9" CRT, and weighed 40 lbs! Everyone asked me why I needed so much power. It beat anything IBM had, until it was orphaned a year later by TI. Back then they had to write efficient software. Now they can write garbage because the hardware makes up for it.