#1 looks to be a power distribution board. AC or DC in to multiply connections.
#2&3 is an old ISA buss modem
The last looks as if it could be an ISA buss parallel printer port.
The other boards look to be pieces of a data acquisition and control system.
The board with the two large squre ICs may be ADCs (I couldn't read the numbers)
Write down the IC numbers and google them. This can help determining what the board may do.
Being that a couple of boards have the old PC ISA buss connections they are probably from the 1980's to early '90's.