skiselev/micro_8088

clock speed setup by keyboard doesn't work

giobbino opened this issue · 6 comments

Hi,
not a big issue, but...

the Ctrl-Alt-Keypad -/+/* sequence doesn't work (at least for me). I checked the speed with the speed.com program and there is no difference at all.

Just to be sure, I tried to modify the clock speed by the Bios, and the speed.com routine correctly shows the different frequency.

What platform are you using?
It will not work on Book8088 because turbo there is not software controllable

micro_8088

edit: bios 1.0 no-ide

That's most certainly should work on Micro 8088. I don't believe that code changed lately.
I did notice previously with some benchmarks that they would either intercept keyboard interrupt and the Ctrl-Alt-Keypad(+/-/*) won't work, or they do the measurement at start, and will not update the numbers while benchmark is running.
Can you check if it switches the turbo modes outside of the benchmarking software?
E.g.:

  1. Run benchmark, record the performance (MHz, or whatever)
  2. Exit to DOS
  3. Use Ctrl-Alt-Keypad(+/-/*) to switch the turbo
  4. Run benchmark again, compare to the data recorded in step 1.
  5. repeat...

I suspected it, so I already did that test before to open the issue, trying to modify the speed from the dos prompt. It doesn't change. I tried many times, i.e. boot (BIOS says 9.45 MHz) -> prompt ms-dos -> press Ctrl/Alt/- -> speed.com -> nothing changes.

Just a question: should this function modify the BIOS value too? Because I did that test too, booting and then trying to modify the speed from dos prompt, by keyboard, and then reboot. No changes at all.

I also suspected the keyboard, so I tried with another one, different model. Nope.

I tested it and it works for me.
Maybe it has to do with the "Pass E0 code" switch (SW2.3)? What's the current setting of that switch in your system?

It was OFF, but I tried to put it to ON, no changes. Just to be sure, I downloaded the same tool you're using, systest, and tried both switch modes. The single keys off the keyboard (ctrl, alt, keypad +, - , *) are working.
Well, not a big issue, I can live without it LOL

BTW I believe it doesn't do any difference, but today I discovered I did a mistake while mounting the backplane, I put all caps 10 uF, but I've seen the C20 is 1 uF. If you think it could make any difference, I'm assembling a 2nd micro_8088, this time with the right cap. It will take a day or two yet...