Yeah, the 74181 was a bit earlier, but what's interesting is that bit-slice is a generic building block technology. For example, the VAX 11/780 used '181s, but

Yeah, the 74181 was a bit earlier, but what's interesting is that bit-slice is a generic building block technology. For example, the VAX 11/780 used '181s, but the compatible 11/730 used 2901s. It's all about how the control microcode is written. The '181 evolved into the 74281 and 74481 with more functions. Then TI jumped to the 74as888 line, which is an 8-bit slice. There are also things like the IDT 49c402, which is basically 4 x 2901 + a 2902 on a single chip.