16 bit Assembly

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SAL   - Shift Left Instruction

The SAL instruction is used to perform an arithmetic shift left, resulting in a signed multiplication.

This command has 3 part the Instruction, A Register or memory address, and the number of bits to shift left.

As each bit is shift it passes in to the Carry flag, where it can be assessed using a conditional jump JC or JNC.

As each bit moves left the lowest bit becomes zero.

Assembly Sample	Description	16 bit Machine Code
SAL AL, 1	;  Shift AL left by 1 bit	D0 F0
SAL AL, CL	;  Shift AL left by value of CL	D2 F0
SAL AL, 0x03	;  Shift AL left by 8 bit immediate	C0 F0 03
SAL AX, 1	;  Shift AL left by 1 bit	D1 F0
SAL AX, CL	;  Shift AL left by value of CL	D3 F0
SAL AX, 0x03	;  Shift AL left by 8 bit immediate	C1 F0 03
SAL [BX], 1	;  Shift memory address left by 1 bit	D1 37
SAL [BX], CL	;  Shift memory address left by value of CL	D3 37
SAL [BX], 0x03	;  Shift memory address left by 8 bit immediate	C0 37 03
SAL [BX+2], 1	;  Shift memory address left by 1 bit	D1 77 02
SAL [BX+2], CL	;  Shift memory address left by value of CL	D3 77 02
SAL [BX+2], 0x03	;  Shift memory address left by 8 bit immediate	C0 77 02 03

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Last Update 11/02/2023