Well, the cheap and dirty way on a 5160 would be to feed a 3xclock signal in at pin 14 on the 8284, then raise pin 13 high. The 14MHz signal still appears on the bus for CGA use, but the rest of the machine runs at the new speed. 8MHz probably wouldn't hurt anything, but your time-of-day clock would run about 60 percent faster.
Some of the early "turbo" XT clones did this.
Here's another possible twist. The 8088 requires a clock with a 33% duty cycle, but the V20 doesn't care. I'm curious what would happen if a V20 were used and the PCLK output (pin 2) on the 8284 were used to feed the CLK (pin 8 ) signal instead.
That would give you a clock of 7.1MHz without upsetting the other peripheral timings.
Worth a try?
Well, the cheap and dirty way on a 5160 would be to feed a 3xclock signal in at pin 14 on the 8284, then raise pin 13 high. The 14MHz signal still appears on the bus for CGA use, but the rest of the machine runs at the new speed. 8MHz probably wouldn't hurt anything, but your time-of-day clock would run about 60 percent faster.
Some of the early "turbo" XT clones did this.
Here's another possible twist. The 8088 requires a clock with a 33% duty cycle, but the V20 doesn't care. I'm curious what would happen if a V20 were used and the PCLK output (pin 2) on the 8284 were used to feed the CLK (pin 8 ) signal instead.
That would give you a clock of 7.1MHz without upsetting the other peripheral timings.
Worth a try?
On a 5160, the 8284 is chip U1, located between the CPU and slot 8.Thank you all for the responses. I do have an original IBM 5160 clocked at 4.77 MHz and a 10MHz V20. I don't expect to run at 10MHz without some components failing. I just want to use a little more of the V20's power. Also, where is the 8284 located on the mobo?
If you're missing the ribbon cable with the connector that goes into the CPU socket, why don't you just make your own? Jameco has the parts that you need - I ordered some awhile back to fix one of the cables for my Sota 286 accelerator that had several broken pins.I don't have the CPU connector. I currently use it for HD FD and EMS.