There's a simple difference between the 2147/4044 types and the 2149/4043 types. The 2147 is an 18-pin 4kx1 SRAM with separate I/O, and the 2149 (also the 2148) is a 1Kx4 SRAM with common I/O. There are lots of numbers that follow these two separate and distinct models, that simply serve to confuse us, but the 2141/2147/4044, etc, are all the same sort of thing, with different timing, of course, but otherwise pretty much the same, and the 2114/2148/2149/4043/7114, etc, likewise are all about the same aside from speed, but are quite different from the former group. Dick ----- Original Message ----- From: "Sipke de Wal" <sipke(a)wxs.nl> To: <classiccmp(a)classiccmp.org> Sent: Monday, February 25, 2002 12:12 PM Subject: Question for Tony or other Old-Chip Wizzards