What is the difference between the E1330B and E1458A?

The E1330B has 4 ports, the E1458A has 12 ports.

The E1458A has the ability to read the actual bit status while it is outputting on a port. Example: SOUR:DIG:DATAn:BYTE:BITm:MON?

The handshaking lines and modes are the same.