RBJ (Redcode oBJect) - Revision history

Dan Tobias: /* Structure Descriptions */ Link page on endianness

2016-12-14T02:00:53Z

‎Structure Descriptions: Link page on endianness

Mark0: Added note about Endianess

2016-12-13T18:49:23Z

Added note about Endianess

Mark0 at 19:32, 17 September 2016

2016-09-17T19:32:25Z

Dan Tobias at 23:36, 29 March 2015

2015-03-29T23:36:30Z

Dan Tobias: Add subcategory; remove some unnecessary redlinks

2015-03-29T19:00:36Z

Add subcategory; remove some unnecessary redlinks

Mark0: fixed image

2015-03-29T14:14:04Z

fixed image

Mark0 at 14:09, 29 March 2015

2015-03-29T14:09:29Z

Mark0: All the content is basically there

2015-03-29T14:05:01Z

All the content is basically there

New page

{{FormatInfo
| extensions = {{ext|rbj}}
| released = 1992
| caption = XRK core display
| endianness = Little_endian
| developed by = Marco Pontello
| reference impl = http://mark0.net/soft-xrk-e.html
| error resiliance = checksum
}}

[[RBJ]] format belong to [[XRK - Extra Redcode Kit]], a complete [[Core Wars]] system for [[DOS]]. [[RBJ]] files contains an assembled binary version of a Redcode Warrior, usually written by the [[XRA - Extra Redcode Assembler]].
[[RBJ]] files also contains info about the warrior's author, name and version of the assembler used, date & time.

== File structure overview ==

An RBJ file is composed of 3 sections: Header, Code, Tail

The Tail is represented by 1 byte used as a checksum.
To verify the integrity of a [[RBJ]] file, simply compare this value to the
calculated checksum of the first (filesize - 1) bytes (that is Header +
Code).

== Structure Descriptions ==

=== Header ===

The Header is 75 bytes long, and is composed as follow:

<pre>
Pos Field Len Data
---------------------------------
0 Version ID 1 Byte - decimal
1 Author 30 Chars
31 Made with 30 Chars
61 Serial Date&Time 8 FP64
69 Split Flag 1 Byte
70 Reserved 1 Byte
71 Program Len 2 Int
73 Start 2 Int
</pre>

=== Code ===

The Code block is a sequence of (Program Len) blocks as follow:

<pre>
Field Len Data
---------------------------------
0 Command 1 Byte
+1 Mode A / B 1 Byte
+2 Operand A 2 Int
+4 Operand B 2 Int
</pre>

=== Tail ===

One Byte as a checksum:

<pre>
Field Len Data
---------------------------------
0 CheckByte 1 Byte
---------------------------------
</pre>

== Fields Descriptions ==

=== Header ===

==== Version ID ====
Decimal (Major ver. * 10 + Minor ver.)
Ex: 12 = v1.2

==== Author ====
Warrior's programmer Name/Nick

==== Made with ====
Assembler used

==== Serial Date&Time ====
Floating Point value: Dec * 86400 = seconds from midnight / Int = days from some date

==== Split Flag ====
0 = No SPL opcode used (program doesn't split)
!0 = Program may use SPL

==== Reserved ====
Not used

==== Program Len ====
Instructions count, length of the code block

==== Start ====

Point to the instruction where execution start

=== Code ===

==== Command ====

<pre>
0 DAT
1 MOV
2 ADD
3 SUB
4 JMP
5 JMZ
6 JMN
7 DJN
8 CMP
9 (not used)
10 SPL
</pre>

==== Mode A / B ====

<pre>
Field A = low nibble
Field B = high nibble

0 "#" Immediate
1 "$" Direct
2 "@" Indirect
3 "<" Indirect autodecremented
</pre>

==== Operand A & B ====

<pre>
2 bytes signed integer
</pre>

=== Tail ===

==== CheckByte ====
Here's how to calc the checksum byte (in [[BASIC]]-like [[pseudocode]]):
<pre>
Sum = 0
FOR i = 1 TO BufferLen STEP 1
Sum = Sum + BufferByte(i)
NEXT i
FOR i = 1 TO BufferLen STEP 2
Sum = Sum + BufferByte(i)
NEXT i
FOR i = 1 TO BufferLen STEP 3
Sum = Sum + BufferByte(i)
NEXT i
FOR i = 1 TO BufferLen STEP 4
Sum = Sum + BufferByte(i)
NEXT i
Sum = Sum AND 255
</pre>
== External links ==
* [http://mark0.net/soft-xrk-e.html XRK - Extra Redcode Kit]
* [http://en.wikipedia.org/wiki/Core_War Wikipedia: Core War]

@@ Line 25: / Line 25: @@
 == Structure Descriptions ==
-Int = 2 bytes in Little-endian format.
+Int = 2 bytes in [[Endianness|Little-endian]] format.
 === Header ===

← Older revision		Revision as of 18:49, 13 December 2016
Line 24:		Line 24:

	== Structure Descriptions ==		== Structure Descriptions ==
		+
		+	Int = 2 bytes in Little-endian format.

	=== Header ===		=== Header ===

@@ Line 11: / Line 11: @@
 }}
-'''RBJ''' format belongs to [[XRK - Extra Redcode Kit]], a complete [[Core Wars]] system for [[DOS]]. RBJ files contains an assembled binary version of a [[Redcode]] Warrior, usually written by the [[XRA - Extra Redcode Assembler]].
+'''RBJ''' format belongs to [[XRK - Extra Redcode Kit]], a complete [[Core Wars]] system for [[DOS]] by Marco Pontello. RBJ files contains an assembled binary version of a [[Redcode]] Warrior, usually written by the [[XRA - Extra Redcode Assembler]].
 RBJ files also contains info about the warrior's author, name and version of the assembler used, date & time.

@@ Line 11: / Line 11: @@
 }}
-'''RBJ''' format belongs to [[XRK - Extra Redcode Kit]], a complete [[Core Wars]] system for [[DOS]]. RBJ files contains an assembled binary version of a Redcode Warrior, usually written by the [[XRA - Extra Redcode Assembler]].
+'''RBJ''' format belongs to [[XRK - Extra Redcode Kit]], a complete [[Core Wars]] system for [[DOS]]. RBJ files contains an assembled binary version of a [[Redcode]] Warrior, usually written by the [[XRA - Extra Redcode Assembler]].
 RBJ files also contains info about the warrior's author, name and version of the assembler used, date & time.

@@ Line 8: / Line 8: @@
 | reference impl         = http://mark0.net/soft-xrk-e.html
 | error resiliance       = checksum
 }}
-[[RBJ]] format belong to [[XRK - Extra Redcode Kit]], a complete [[Core Wars]] system for [[DOS]]. [[RBJ]] files contains an assembled binary version of a Redcode Warrior, usually written by the [[XRA - Extra Redcode Assembler]].
+'''RBJ''' format belongs to [[XRK - Extra Redcode Kit]], a complete [[Core Wars]] system for [[DOS]]. RBJ files contains an assembled binary version of a Redcode Warrior, usually written by the [[XRA - Extra Redcode Assembler]].
-[[RBJ]] files also contains info about the warrior's author, name and version of the assembler used, date & time.
+RBJ files also contains info about the warrior's author, name and version of the assembler used, date & time.
 == File structure overview ==
@@ Line 18: / Line 19: @@
 The Tail is represented by 1 byte used as a checksum.
-To verify the integrity of a [[RBJ]] file, simply compare this value to the
+To verify the integrity of a RBJ file, simply compare this value to the
 calculated checksum of the first (filesize - 1) bytes (that is Header +
 Code).

@@ Line 2: / Line 2: @@
 | extensions             = {{ext|rbj}}
 | released               = 1992
-| image                  = [[File:cw.png]]
+| image                  = cw.png
 | caption                = XRK core display
 | endianness             = Little_endian