Yeah, something like that. There were 12 built, I've had my hands on four of them. Four channels, analog, yes 50 Mega-bit, yes, 1984 (or was it 86? one or the other). All wire wrap inside.
They've tried replacing the thing several times, everything they try to replace it with fails to perform. That old clunker right there is a case of archaic tech that modern stuff just can't duplicate. Of course trying to find a better 50 Mbps four channel analog modem is akin to trying to a better weapon but insisting on bow strings and arrows, so we'll forgive that.