HP 48 ram card from Ebay: why would self-test be required?

[rprosperi]

It's not complicated at all, it's simple to just purchase one of these:

https://www.ebay.com/itm/224291967059, $269.00

https://www.ebay.com/itm/224302800251, $269.00

Less than 1/3 of that price is where you get into complicated.

p.s. But please don't buy one of those, I'd hate to be part of giving business to someone that prices like that...

p.p.s. It's probably also worth adding I've used a Grid (previously wrote Epson by mistake) 1MB card for many years with no issues at all.