Our firm is engaged in development of the programs for an industry. For the devices we use INTEL D201GLY. The exchange of the data with the external device is made through port of the printer. Very important precisely to fulfil intervals by reception / transfer through port. The program is written for MS-DOS in language Borland PASCAL 7.0. Now we successfully use the instruction CLI for prohibition of interruptions and precise observance of intervals. At attempt to start the program on INTEL D945GCLF with the processor ATOM 1.6 intervals are not observed. The instruction CLI does not work on an interdiction of interruptions. The keyboard, USB etc. continue to work. Periodically exchange through port interrupts on some time, and then is again restored. The masking IRQ0-15 stops an exchange with the keyboard, but all the same exchange interrupts. What command I can forbid ALL interruptions on short time by and sustain the necessary intervals.
Beforehand is grateful.
Try disabling USB legacy support in BIOS. Disable USB keyboard, mouse and detection of USB thumb drives. It may help. Most likely reason for working periferials with interrupts disabled is that BIOS and board use NMI which is of course wrong thing to do so you might want to consider different board and/or vendor as well.