The Alien ALR-9800/9900 require a power supply that provides multiple voltages as per the picture. The problem is the -ve voltage on pin 5, otherwise you'd be able to whip up one for a couple dollars.. So you're generally SOL, which is why they're so cheap as they require the expensive power supply... According to my email that came up when I was looking things up for this reply,
I recycled my 9800 reader in 2020, but still have a couple 9900's lol... They use the same supply, but allow you to load applications into the reader so I wrote a ipico wedge for them
so that it can talk directly to finishlynx. FYI I was able to buy a supply in 2018 (the last time I tried) from
pc-canada.com, and they still list the part. They don't generally stock oddball things, but you could try checking with them if their suppliers have stock. (
https://www.pc-canada.com/item/alien-power-supply-and-cord-for-alr-9800-and-9900/alx-414-3 ).