NAME	TAS -- Test and set operand
SYNOPSIS	TAS <ea> Size = (Byte)
FUNCTION	Test of a byte addressed by <ea>, bits N and Z of SR are set according to result of test. Bit 7 of byte is set to 1. This instruction uses read-modify-write cycle, which is not dividable and allows synchronisation of several processors. But this instruction is NOT ALLOWED ON AMIGA! This instruction can easily be substituted by BSET.
FORMAT	15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 0 1 0 0 1 0 1 0 1 1 MODE REGISTER   <ea>
REGISTER	<ea> is destination, addressing modes are the following: Addressing Mode Mode Register Dn 000 No reg. Dn An - - (An) 010 No reg. An (An)+ 011 No reg. An -(An) 100 No reg. An (d16,An) 101 No reg. An (d8,An,Xi) 110 No reg. An (bd,An,Xi) 110 No reg. An ([bd,An,Xi]od) 110 No reg. An ([bd,An],Xi,od)110 No reg. An Addressing Mode Mode Register Abs.W 111 000 Abs.L 111 001 (d16,PC) - - (d8,PC,Xi) - - (bd,PC,Xi) - - ([bd,PC,Xi],od) - - ([bd,PC],Xi,od) - - #data - -
RESULT	X - Not affected. N - Set if MSB of byte is set. Cleared otherwise. Z - Set if byte is zero. Cleared otherwise. V - Always cleared. C - Always cleared.

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