8051 disassembly

[Dale Klein <daklein@netzero.net>]

	I have been playing with DHC11 (thanks very much to Peter for putting this 
out there) and trying to figure out for myself how my LT1 works.  I am 
hoping eventually to find the tables for decel fuel cutoff, and exactly how 
DFCO and the idle / follower IAC modes work.

	I'm a real amateur at assembly language, maybe someone out there can tell 
how the following section works at a glance.....

	This is from the t-side.  I'm trying to figure out what vector table to 
define in the control file, for the following DHC11 message line:
Indexed Call/Jump at $4F83, may require a vector table.
	
	I tried using the following control line, but I think it is wrong.
vectors $4f85 4 some_1 somevector

Here's the code near there, and my misunderstanding of it.... 8>(

4F6E	12 83 08 06     	brset	l_0083_, #%00001000, @80
4F72	15 83 07        	bclr	l_0083_, #%00000111
4F75	15 A8 0F        	bclr	L00A8, #%00001111
4F78	D6 7C           @80	ldaB	L007C			load 124(or mem $007c)? into B
4F7A	C4 03           	andB	#%00000011		B and 3 --> B  (what does this do...?)
4F7C	CE 4F 85        	ldX	#$4F85			load addr (=$4f8d) --> X
4F7F	58              	lslB				shift B left (multiply x2)?
4F80	3A              	aBX				X + B --> X
4F81	EE 00           	ldX	0, X
4F83	6E 00           	jmp	0, X			go there, but where, what vector to specify..?
;
;
4F85	                	db	$4F, $8D, $4F, $A7, $4F, $B2, $4F, $D0, $BD, $8F
4F8F	                	db	$E4, $BD, $8F, $EB, $BD, $91, $22, $BD, $92, $26
4F99	                	db	$BD, $91, $F1, $BD, $93, $12, $BD, $93, $7A, $BD
4FA3	                	db	$94, $0D, $20, $2C, $BD, $94, $4A, $BD, $94, $80
4FAD	                	db	$BD, $95, $0B, $20, $21, $BD, $96, $DA, $BD, $9C


	Any advice (other than Give Up!!!!) or hints would be great.	
	
Thanks,
	Dale 

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