Oops.  Yes your variable1 is certainly a label.
It defines "a" memory location or label in the
file register space.  So a (relocatable) 
example looks something like this:

   UDATA                      ;define some Uinited DATA
variable1 RES 1               ;some single byte file register memory 
                              ;  location in some bank
                              ;
#define jump 0                ;this is a bit position of the zero position
bit
                              ;
   CODE                       ;
   BANKSEL  variable1         ;find variable1 memory bank
   bsf      variable1,jump    ;set bit 0 of variable1


I shoved the above example into a project of mine and the list file shows:

00196f   1283     BCF       0x3,0x5           BANKSEL  variable1
001970   1303     BCF       0x3,0x6
001971   142a     BSF       0x2a,0x0          bsf      variable1,jump

Viewing the map file reveals:

 .udata      udata   0x000020       data   0x00000b

and

variable1   0x00002a       data  

Hence the two RP regs in the STATUS reg are set to zero
(STATUS at 0x03 and RP0 and RP1 are in bits 5 and 6)
to select the variable1 bank and the f in the bsf
instruction is 0x2a and the b is 0 as #defined above.

So this is VERY clear in my mind now.

Thanks for pointing out my error.

GL,
Walt...

-----Original Message-----
From: Martin SchŠfer [mailto:schaefer@ELEKTRONIK21.DE]
Sent: Thursday, April 20, 2000 5:48 AM
To: PICLIST@MITVMA.MIT.EDU
Subject: Re: Object ASM Blues


Walter Quitt wrote:

> In other words RX can't be an EXTERN.

That's ok.

> Yikes, now that I look again jump can't be EXTERN
> either I don't think.  It's gotta be a file register and
> not some address.  Looking at the definiation of EXTERN
> directive syntax: extern ,label> [, <label> ] and labels
> are addresses neither jump or RX can be labels.

That's not correct, because a RAM location will also be
addressed as label.

variable1       RES  1

That' a label, isn't it?  (See examples in MPASM Users Guide,
DS33014G, p.77, Chapter 6.8)

Martin

;**********************************************
;**   name:      Martin Schaefer             **
;**   company:   elektronik 21 GmbH, Germany **
;**   e-mail:    schaefer@elektronik21.de    **
;**********************************************


> -----Original Message-----
> From: Quitt, Walter [mailto:wquitt@microjoin.com]
> Sent: Thursday, April 20, 2000 2:41 AM
> To: PICLIST@MITVMA.MIT.EDU
> Subject: Re: Object ASM Blues
>
>
> From the datasheet:
> bsf f,b
> where  0<=f<=255 and 0<=b<=7
> f is a file register and b is a bit number
>
> So you are supposed to be trying to set bit b in file reg f.
>
> The assembler doesn't know what b (or RX) is (or will be.)
> b is a fixed number 0 - 7 which represents which bit to set.
> So if you defined RX as a number in an include you'd be OK.
> If RX is another file register or a redefined peripheral
> register, you are out of luck.  In other words RX can't be
> an EXTERN.  Yikes, now that I look again jump can't be EXTERN
> either I don't think.  It's gotta be a file register and
> not some address.  Looking at the definiation of EXTERN
> directive syntax: extern ,label> [, <label> ] and labels
> are addresses neither jump or RX can be labels.   So I
> guess you gotta rethink what you are doing.  Looks like
> brainfad to me. :-) :-)
>
> -----Original Message-----
> From: Stephan Kotze [mailto:stephank@IAFRICA.COM]
> Sent: Wednesday, April 19, 2000 3:35 PM
> To: PICLIST@MITVMA.MIT.EDU
> Subject: Object ASM Blues
>
>
> Dear list
>
> I am at my wits end. Can someone please explain to me why
> MPASM won't allow
> me to do the following:
>
>     LIST P=16F874
>     include p16F874.inc
> EXTERN RX, jump
>     CODE
> RECEIVE_BYTE
> ......
>     bsf jump,RX ; set bit for jump
> .......
>     return
> end
>
> I keep getting this error when trying to make an object file
>
> Error[151]   E:\OBJECT\MAST232O.ASM 35 : Operand contains unresolvable
> labels or is too complex
>
> Stephan
>