FF7/Field/Script/Opcodes/79 MINUS2! - Revision history

BukTop: 5 revisions imported

2019-05-23T02:17:31Z

5 revisions imported

my_wiki>BukTop: 4 revisions imported

2018-04-04T09:34:40Z

4 revisions imported

my_wiki>Synergy Blades at 17:12, 6 October 2006

2006-10-06T17:12:51Z

my_wiki>Synergy Blades at 17:12, 6 October 2006

2006-10-06T17:12:10Z

my_wiki>Halkun at 22:40, 2 September 2006

2006-09-02T22:40:57Z

my_wiki>Halkun at 22:38, 2 September 2006

2006-09-02T22:38:20Z

New page

* Opcode: '''0x79'''
* Short name: '''MINUS2!'''
* Long name: Saturated Subtraction (16-bit)

==== Memory layout ====
{| border="1" cellspacing="1" cellpadding="3" style="border: 1px solid black; border-collapse: collapse;"
! width="40" | 0x79
! width="40" | ''D/S''
! width="40" | ''Dest''
! width="40" | ''Oper''
|}

==== Arguments ====
* '''const Bit[4]''' ''D'': Destination bank
* '''const Bit[4]''' ''S'': Source bank
* '''const UByte''' ''Dest'': The destination variable, to which the operand is added.
* '''const UByte''' ''Oper'': The operand, added to the destination.

==== Description ====
Adds two numbers together and stores the result back into "Dest". The result of the addition is capped at 255.
If the Source Bank is 0 then the â€œOperâ€ is added to the destination value.
If the Source Bank is an 8 bit bank, then the â€œOperâ€ is the address in that bank where the operand is.

@@ Line 18: / Line 18: @@
 ==== Description ====
-Subtracts "Oper" from "Dest" and stores the result back into "Dest". The result of the subtraction is capped at -32768. Oddly enough the result is not capped at the positive end, 32767, so subtracting a large negative number from a large positive number will still produce wrap-around.
+Subtracts "Oper" from "Dest" and stores the result back into "Dest". The result of the subtraction is capped at -32768. The result is not capped at the positive end (32767), so subtracting a large negative number from a large positive number will still produce wrap-around.
 If the Source Bank is 0 then the â€œOperâ€ is subtracted from the destination value.
 If the Source Bank is an 16 bit bank, then the â€œOperâ€ is the address in that bank where the operand is.

← Older revision	Revision as of 02:17, 23 May 2019
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← Older revision	Revision as of 09:34, 4 April 2018
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@@ Line 8: / Line 8: @@
 ! width="40" | ''D/S''
 ! width="40" | ''Dest''
-! width="40" | ''Oper''
+! width="80" | ''Oper''
 |}

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 * '''const Bit[4]''' ''D'': Destination bank
 * '''const Bit[4]''' ''S'': Source bank
-* '''const UByte''' ''Dest'': The destination variable, to which the operand is added.
+* '''const UByte''' ''Dest'': The destination variable, to which the operand is subtracted.
-* '''const UByte''' ''Oper'': The operand, added to the destination.
+* '''const SWord''' ''Oper'': The operand to be subtracted from the destination.
 ==== Description ====
-Adds two numbers together and stores the result back into "Dest". The result of the addition is capped at 255.
+Subtracts "Oper" from "Dest" and stores the result back into "Dest". The result of the subtraction is capped at -32768. Oddly enough the result is not capped at the positive end, 32767, so subtracting a large negative number from a large positive number will still produce wrap-around.
-If the Source Bank is 0 then the â€œOperâ€ is added to the destination value.
+If the Source Bank is 0 then the â€œOperâ€ is subtracted from the destination value.
-If the Source Bank is an 8 bit bank, then the â€œOperâ€ is the address in that bank where the operand is.
+If the Source Bank is an 16 bit bank, then the â€œOperâ€ is the address in that bank where the operand is.