The SuperEISA is back from the dead (for now at least). The best I can tell is that the BIOS and socket both had a little corrosion going on. It was a white coloured residue that's easy to overlook as it is close to the original pin colour (but not shiny at all). I noticed many of my old ROM chips have this problem.
The nice thing about the Super EISA is that the clockgen is socketted and I can easily switch between that or a metal can oscillator. This lets me experiment with non standard frequencies. As I have not been successful at running a Cyrix 5x86 at 2x66 (and don't have a 4X part) I thought it would be interesting to test my chips out with a 44.236MHz crystal using a 3X clock. At 44.236MHz my board is much more stable than at 50MHz, and the memory performance is quite epic. I am getting an average of 57MB/sec in speedsys. After confirming stability of this speed with an AMD 5x86 (3x44.236 = 133MHz) I decided to give my four Cyrix 5x86 chips a good.
I have an IBM 5x86C 100HF, a Cyrix S1R3, and two Cyrix S0R5 chips. The 5x86C and S1R3 were the only two that were semi viable at 133MHz. I am able to complete speedsys, but running demanding 32-bit games will lock the system up within a few minutes. Keep in mind this is at 3.45V. I will attempt to modify my VRM for 3.75V and try again.
I tested amd 5x86 at 4x44.236=180MHz as well, but none of my 3 chips could handle it at 3.45V. I suspect even at increased voltages it will still not happen.
"Will the highways on the internets become more few?" -Gee Dubya
V'Ger XT|Upgraded AT|Ultimate 386|Super VL/EISA 486|SMP VL/EISA Pentium