I have such one, but I'm too lazy to dismantle the machine to look at the mobo and identify it. One notable thing I remember is that its manual says do not toggle turbo while the machine is running.. so naturally I do just that 😅 The system hangs except when running certain programs.. one of which was Norton System Information's CPU benchmark. Not sure what kind of slowing technique requires the machine to be off.

M-Tech made a number of oddball boards like this one, a Socket 7 with 30-pin SIMMs and a turbo switch: https://theretroweb.com/motherboards/s/m-tech … pentium-pci-isa but I don't know exactly what it does.

jakethompson1 wrote on 2025-06-24, 04:45:

M-Tech made a number of oddball boards like this one, a Socket 7 with 30-pin SIMMs and a turbo switch: https://theretroweb.com/motherboards/s/m-tech … pentium-pci-isa but I don't know exactly what it does.

I have an M-Tech R653 (Slot 1, 440FX) and even that one has a turbo switch header! The manual only mentions this:

Connector for the lead from a turbo-switch mounted on the system case.

When I have the time I can try connecting a switch to see what it does...

TheMobRules wrote on 2025-06-24, 04:56:

I have an M-Tech R653 (Slot 1, 440FX) and even that one has a turbo switch header

I also have a SiS 5511 based mobo with turbo header and it apparently adds waitstates. So it may be possible this chipset offers such functionality.

A number of Gigabyte Socket 7 boards support the turbo function (GA-586ATV, GA-586HX, and others). De-turboing the board switches the FSB to 50MHz.

If you're already running at 50 MHz, it would do nothing, but if running at a higher FSB it provides a marginal slowdown.