Grant Edwards <grant.b.edwards at gmail.com>: > In general CISC processors like x86, AMD64, 68K have read-modify-write > instructions that allow you to increment a memory location or > set/clear a bit in memory with a single instruction: >> INC.W [R0] # increment memory word whose addr is in register R0 The x86 instruction set has a special lock prefix for the purpose: <URL: http://stackoverflow.com/questions/8891067/what-does-the-lock-ins truction-mean-in-x86-assembly> Marko