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dělávalo se to přes ty interní timery AdLibu - prostě se přes 0x388/0x389 spustily a testovalo se, jestli běží.

V manuálu, co mám, to je popsaný trošku zdlouhavě:

|      1)  Reset both timers by writing 60h to register 4.
|      2)  Enable the interrupts by writing 80h to register 4.  NOTE: this
|          must be a separate step from number 1.
|      3)  Read the status register (port 388h).  Store the result.
|      4)  Write FFh to register 2 (Timer 1).
|      5)  Start timer 1 by writing 21h to register 4.
|      6)  Delay for at least 80 microseconds.
|      7)  Read the status register (port 388h).  Store the result.
|      8)  Reset both timers and interrupts (see steps 1 and 2).
|      9)  Test the stored results of steps 3 and 7 by ANDing them
|          with E0h.  The result of step 3 should be 00h, and the
|          result of step 7 should be C0h.  If both are correct, an
|          AdLib-compatible board is installed in the computer.