The 11/05 and 11/10 are the same CPU... If I remember correctly, the difference in designation was based on whether it was OEMed or not. Same for the 11/15,20 and the 11/35,40 I have a working 11/05 (with two core stacks -- the original 16Kw MM11-?? memory which came with it, and a 16Kw MM11-DP I got for it at a later time). I also have several pdp-8s... Megan Gentry Former RT-11 Developer +--------------------------------+-------------------------------------+ | Megan Gentry, EMT/B, PP-ASEL | Internet (work): gentry!zk3.dec.com | | Unix Support Engineering Group | (home): mbg!world.std.com | | Compaq Computer Corporation | addresses need '@' in place of '!' | | 110 Spitbrook Rd. ZK03-2/T43 | URL: http://world.std.com/~mbg/ | | Nashua, NH 03062 | "pdp-11 programmer - some assembler | | (603) 884 1055 | required." - mbg | +--------------------------------+-------------------------------------+