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I also decided (see Chapter 14 for additional details) to change the tick rate of the PC from the standard 18.20648Hz to 200Hz (i.e., 5ms between ticks).
L15.2(10) This statement declares an 8-bit variable (OSTickDOSCtr) that keeps track of the number of times the ticker is called. Every 11th time, the DOS tick handler is called. OSTickDOSCtr is used in OS_CPU_A.ASM and really only applies to a PC environment.
OS_CPU.H, Floating-Point Functions
This port defines three special functions that are specific to the floating-point capabilities of the 80x86. In other words, I had to add three new functions to the port to handle the floating-point hardware.
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