Hi, I'm putting together a system with a Tyan Tomcat III motherboard that I purchased new many years and never got around to using. I'm trying to install a P233 MMX chip on it, but set at the max speed of the board, which is 200 Mhz. max. I think it should be possible to rate the chip lower than what it's mf'd for, if I remember. The board is the S1563S-512. I could use help with some of the jumpers for the CPU Voltage Regulator Settings. The manual (page 12) (available here: ftp://ftp.tyan.com/manuals/m_s1563_100.pdf). The manual is wrong on the top of that page where they list Jumpers 61-65 (found it on the Tyan site) Jumpers 60-62 are really 37, 38 and 39. Jumpers 63-65 are really 42, 43 and 44. Now, they say that the rest of the chart is correct and I assume that I should follow the jumpering instructions under the "2.85v" column, since the back of the chip says "2.8v" or so, and the Intel website lists the core voltage for that chip as 2.7-2.9v. That's all easy enough. That shows how to set jumpers 40-44 and 52-54. That's easy too. Now, what confuses me is that the other possible jumper setting is for P54C (Pentium) & Cyrix, which isn't my chip. However, they list instructions for jumpering 40-44 and 52-54, just like with my chip, BUT they list the additional jumpers 37, 38, and 39. Now what do I do with those if I'm using the MMX chip, as they don't show any instructions for that.? Next and last question. There are jumper settings for "DRAM Voltage Setting". You have a choice of 5v (default) or 3.3v. How do I know which to chose and which would I chose to set it for? I assume Default, but I don't want to make any assumptions and find out that I'm wrong later. They say that it can cause damage if set incorrectly. Thanks for any help! Danny