Before revision: FC=DTL by Mullard FD=PMOS by Mullard FJ=TTL by Mullard (7400 series) FL=TTL by Siemens (7400 series) FN=ECL by Telefunken FP=HTL by Telefunken FS=SECL by Telefunken FY=ECL by Siemens FZ=HTL by Siemens GD=PMOS by Siemens (MEM1000 series) GH=ECL by Philips GJ=TTL by Mullard (74H00 series) GT=TTL by Mullard (74S00 series) Unfortunately the serial number does not specify the same type of gate in each family, e.g.
After revision: FQ=DTL by SGS-ATESFC=DTL by Mullard FD=PMOS by Mullard FJ=TTL by Mullard (7400 series) FL=TTL by Siemens (7400 series) FN=ECL by Telefunken FP=HTL by Telefunken FS=SECL by Telefunken FY=ECL by Siemens FZ=HTL by Siemens GD=PMOS by Siemens (MEM1000 series) GH=ECL by Philips GJ=TTL by Mullard (74H00 series) GT=TTL by Mullard (74S00 series) Unfortunately the serial number does not specify the same type of gate in each family, e.g.