I thought I would try to avoid going into the office to download the
5Meg MPLAB and I am trying to get by with MPSIM without the docs for my
first simple program tonight. Can someone help me get over this first
hump with these two simple questions.

1) The code below is from a sample known working program with P16C54
specidied in the assembler code. It loads into mpsim OK. The code sets
OPTION for 00000111 in order to use a prescaler of 1/256 and clock TMR0
from the instruction clock. In either single step or execute mode, the
code loops as it should in the "d2" loop, but TMR0 never decrements
according to the simulator's display. I am allowing it to run 64K +
instructions. One confusing clue is that during one execution the WDT
expired. What might I be doing wrong here.


org     1FF
        goto    start
        org     0
;
delay   movlw   0x08            ;522ms delay
        movwf   count
d1      movlw   0x01
        movwf   TMR0
d2      movf    TMR0,w
        btfss   status,z
        goto    d2
        decfsz  count
        goto    d1
        retlw   0x00

start   movlw   b'00000111'     ;TMR0 = internal, prescaler = 1/256
        option
        clrf    port_a
        clrf    port_b
        call    delay

2) In my own program I have specified a P16F84 in the assembler. This
compiles without errors or warnings. However, when I go to load this
into MPSIM, I get a "Cannot Pre-Assign target device" message. The only
thing I can think of is that this DOS version of MPSIM that I downloaded
from the microchip WEB site this week does not support the P16F84. Can
someone tell me what is happening?