Individual Instruction Descriptions

MOV AP1,

3

; Point to

loc corresponding to

 

 

; extended

word in acc

MOVS A0,

*R0

;

R0 POINTS TO VALUE

IN MEMORY

EXTSGN A1

 

;

not string version

as above

Alternatively, the following code can do the same thing but requires more code:

 

MOV AP0, 0

;

POINT TO LSW OF ACCUM STRING

 

MOV AP1, 3

;

Point to loc corresponding to

 

 

;

extended word in acc

 

ZAC A1

;

INITIALIZE EXTENDED SIGN VALUE as positive

 

MOVS A0, *R0

;

R0 POINTS TO VALUE IN MEMORY

 

JNS POSITIVE ;

branch around negative extension,

 

 

;

accepting default pos extension

 

NOT A1

; INVERT EXTENDED SIGN WORD FOR NEG CASE POSITIVE

 

......

 

 

See Also

EXTSGN

 

 

Example 4.14.17.1

EXTSGNS A0~

 

 

Sign extend accumulator string A0~. See the previous italic text on the bug in this instruction at the present time.

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