As near as I can decode the instruction sheet - 1.   No board cuts are needed 2.   The six chips are: a replacement for U111 (1Kx4 ROM), 2 PAL's for U110 and U173, a 74ALS00 for U155 and a 74ALS10(04) for U166. I do remember the mod you are describing - in fact, I think I have a kit for doing that around here somewhere. Never, obviously, installed either one! Bob Groh Dan Lanciani <ddl-cctech@danlan.com> wrote:<blockquote class="replbq" style="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; padding-left: 5px;"> |The 2nd item is a ZMAX - Z100 motherboard memory maximizer kit by Rick |Pegg and produced and marketed by Graymatter Applications Software. |Works only with later module Z-100 motherboards, does include written |instructions for the modifications, the 6 specialized chips required and |27 (3 banks x 9 ICs per bank) 256K bit D-RAMS. Gives you a wacking 768K |bytes of memory! You can also use the 32K RAM chips you remove to |upgrade the video system (instructions included). Interesting; what are the 6 specialized chips? We used to do this with one multiplexor (74LS157?) and a bent pin on the memory decode PAL. Older machines needed a newer monitor ROM as well. Dan Lanciani ddl@danlan.*com -- Delivered by the SEBHC Mailing List If you would like to unsubscribe, please send the word "unsubscribe" in the **body** of a message to sebhc-request@sebhc.org. </blockquote>