Greetings. New to list , and read thread re: combining/running SIMM and DIMM RAM, on older socket 7 boards. Here's my premature success. On an M Technology R542 Mustang-ultra (ver.2), installed 2 32 Meg 72 pin SIMM's + 2 32 Meg DIMMS. (I think DIMM's are PC 66). Pairs are matched. FWIW, PC showed 96 megs RAM, booted to OS. Haven't put through paces yet. My ?. Are some 168 pin DIMM's keyed *slightly* differently? 168 pin DIMM's from Umax s900 (Apple clone) wouldn't fit in aforementioned PC. Should I use *only* PC 66 168 pin DIMM's? Or will PC 100 or PC133 fit? TIA, Goofymuso

If this M tech board is like one I had you are going to burn out the Dimms. There is set of voltage jumpers that apply whatever the set voltage is to all memory slots. These different memory modules require different voltages. Maybe your board is different. I had 3 of the R534 series boards and that is how they worked.

Thanks for reply OtheHill. >There is set of voltage jumpers that >apply whatever the set voltage is to all >memory slots. These different memory >modules require different voltages. >Maybe your board is different. No, my board is the same. I checked on line for info on this board before working on it, and found it supported 3.3/5.0 volts, but, assumed it applied to DIMM's only. Didn't know settings applied (stands to reason) to SIMM's as well. Thanks *very* much for heads up. Pretty sure all installed RAM is 3.3 V but will search net' for specs. But if I don't find info...... Do you know what silkscreened or otherwise info I look for on RAM to determine voltage? SIMM's are: Kingston KVR8X32-60ET/32 with: VG2617405DJ chips. SDRAM's are: LG semiconductor GMM2644233CNTG with: LGS GM72V16821CT10K chips. Cheers. %00

Oops. Hang on. My last post was incorrect. Specs/jumper info for M Technology R542 Ver. 1 at docs.van-diepen.com states that "DIMM Voltage Configuration" can be set to 3.3v or 5v " and: "Board accepts EDO memory" Nothing there re SIMM voltage. Searched net'. My Kingston EDO RAM is 5v. Any takers/input re possible seperate voltage for SIMM slots? Is all 72 pin SIMM EDO RAM rated at 5v ? TIA, Goofymuso. %00

Those older simms were 5 volts I think. I don't know if the voltage is one the module or not. Try using Everest Home Edition to find the Voltage. I'm not sure if it will give the applied voltage or the design voltage. I think the design voltage is what will display.

Installed DIMM's @ correct V . SIMMS also installed. Rig shows correct amount of RAM though I had to try a different config slotwise for DIMM's to achieve this. i.e. Banks 1 & 3. Theres 3 in total. Appreciate info re older SIMMS. Likely my SIMM's are all 5v. Is Evergreen a software util.? I will hunt it down. If SIMM's melt in meantime, well, lesson learned on my part! Thanks again. %00