It is MY #retrocomputing pleasure to welcome the Atari Portfolio 16-bit kinda-MS-DOS-compatible handheld PC to the crew!
Powered by 3 AA batteries and coming to us from 1991, I can already tell it will fit right in.
Eventually I will be stocking up on a few choice peripherals for the Portfolio, including a system RAM memory expansion card (with peripheral port pass-through, kind of like an ur-Sonic & Knuckles experience), a serial interface, and a diagnostic interface produced for licensed repair shops and peripheral developers, all due to the diligence of a single vendor, aptly named Best Electronics, who's maintained stocks longer than the original company stayed in business.
They even carry overclocking kits that can increase performance by over 33 percent of the stock configuration! 33%, maybe even more! We're talking almost double-digit megahertz!
Software distribution was via ROM cards like this one, the base File Manager and Tutorial card that came with each Portfolio.
@remotenemesis I believe hardware-wise they're almost identical
The base system at launch cost US$400, which is like USD$800+ in cool 21st Century fiat currency, so I got it for pennies on the dollar.
Shrewd investor, me. Finding that purchasing power sweet spot.
@djsundog That looks very similar to a Lynx game card.