> They had been recommended to me as 'tanks' and were much more reliable than the dynamic memory cards of the time.

Interesting to hear that.... I've recently been reading through old issues of DTACK Grounded, and Hal Hardenberg said similar things, and at length, about the reliability improvements you get with static memory over dynamic. (A few years in, he was also selling dynamic memory products, presumably for scale, and was no longer able to ground DTACK in his designs.)