Octopart links to chips in BOM 13 U1, U3 PAL20L8 or better e.g. 22V10 14 U11,U12 27256 15 U14,U15 74ALS573 Transparent latch, 8-bit 16 U2 74LS74 17 U4 74LS32 18 U5 74LS646 Octal bus transceivers and register 19 U6 74ALS00 20 U7 74LS175 21 U8 NS32202...