Terminal emulators began early. On the day I first met an HP 3000 in 1984, the box for the Walker, Richer & Quinn product Reflection sat on top of a PC in my HP Chronicle office. HP climbed into the field soon enough. HP AdvanceLink didn't do anything more than Reflection to emulate 3000 terminals, and often less. AdvanceLink had the system vendor's label, though. WRQ did very well selling against the HP product. HP relented and started to sell and recommend Reflection.

Terminal emulation launched itself into the iOS world about 25 years later. One vendor sells a product that emulates a vast range of legacy terminals. In 2013 TTerm Pro entered the market as a solution for fully mobile legacy terminal use.

Finding such a terminal in the wild can be rare today. The software that needs it, though, may still be on the job. Development started in 2013 for TTerm Pro. The iOS app from TTWin, all of $19.95, is getting maintenance and bug updates once more. TTWin has repaired the ALT key issues for several European-language software keyboards, including those for HP 3000s.

There's an interesting range of fixes. In this year's version 1.5.0, Bluetooth scanners no longer inject CR characters midway through barcode scanning. The fact that Bluetooth has anything to do with vendor-specific hardware such as terminals is worth a closer look.

It's mind-boggling to consider that an HP 2392, launched in 1984, is emulated 36 years later. That text-only terminal, if you can find one, cost $1,295 when it was new. The terminal's 12 inches of CRT screen produced characters on a 7x12 dot matrix. HP included a tilt and swivel base for each terminal.

It was a different world in 1984. "The most common cause of failure," says the HP Computer Museum's collector notes, "is a bad power supply. The first step in refurbishing these terminals is to remove the top case and remove the power supply PCB. (Printed Circuit Board) This PCB contains some metalized paper capacitors that are prone to failure and smoking with age. These capacitors are easily replaced."

That replacement is true if you've got a source for paper capacitors. Not so much? Today there's a resource for legacy hardware in many forms. For example, Stromasys sells Charon to use Intel servers for emulating PA-RISC hardware. And TTerm employs a $1,250 iPad Pro, about 13 inches in size, to carry terminal access anywhere we find a cell signal.

That's 13 inches of terminal you can carry around like a book.

Hardware never dies when good emulation engineering keeps it alive. Download that TTerm Pro app and marvel at the time machine bounty. In 1984, that $1,250 delivered 7x12 matrix characters. Nothing else on that 12 inches, not like the iPad Pro of today. One important reason to preserve legacy terminals: Companies continue to use the software that relies on them.