On the Apple IIe Microloop System 1100 Spirometer, by Medical Graphics Corporation 

I was recently idly scrolling through the vintage Apple listings on eBay and came across something I’d never seen before: the Microloop 1100 Spirometer.

Microloop 1100 Spirometer

According to the listing, this beast hails from 1987 and is built around an Apple IIe and a 9-inch CRT, with some extra goodies:

  • A 5.25-inch floppy drive
  • 80 column / RAM expansion
  • An Apple CAT II modem
  • An Apple CAT expansion card for 1200 Baud
  • A Microbuffer II
  • A Disk II card
  • An 16 channel Interactive Structures A113-A A/D card
  • A Titan accelerator
  • A Titan 128K RAM expansion

This machine was crammed into a custom case and was hooked up to a spirometer, which is used to measure the volume and movement of air into and out of the lungs. This medical instrument interfaced with the Apple IIe via that 16-channel Interactive Structures A113-A card, which operated as an analog-to-digital converter for incoming data.

(These days, spirometers way, way more portable.)

Finding more information about this machine online proved futile. I ran across this thread about it, but that was about it. At an asking price of $4,999.95, this blog post is as close as I’ll get to the Microloop System 1100 Spirometer.