Put it this
way, it's a lot easier for me to find the dead chip in an
M200 (or in anything else for that matter) and replace it than to fight
with some FPGA-based thing...
Well, I suppose that would depend on the availability of documentation, etc.
I repaired my first M200 (which does exist, it's a Hollerith card reader)
with no documentation. And today you can get the manual from Bitsavers IIRC.
BTW, it isn't really relevant to your point, but
the Blinkenlights thingy is
TTL.
In which case it almost certainly involves some other computer, like a
PC. I've mentioned before that I've never seen a properly documented
modern PC....
-tony