Tandy Logix-Kosmos

This xxxNNN convention was some European attempt to standardize the various logic families in the 70s; I think this came from JEDEC as a joint venture of Siemens, Philips, and some other vendors). The idea was basically to have the first letter to describe the logic family, the second a temperature range or a sub family (e.g. Z=noise immune logic with 12Vcc), the third a functional category. The three digit number then refers to the actual circuit. So, an FLH101 was a TTL (F) with temperature range 0..70degC (L), and combinational circuit (H). The number here refers to 4 totem pole NAND-2 gates -> so this is the well-known 7400. J in the third place denotes some flip flop or counter, K is a monoflop, L is a decoder (e.g. 74141, 7445, 7447). I have to look up the complete convention in some old Siemens data books.