> 1.I must use 3 IO to control the shift register. (data, srclr, clock)
#define data PORTA,0
#define srclr PORTA,1
#define clock PORTA,2

I am used to define port pins as variables when it's possible so I dont end
up not knowing which pin is doing what.

> 2.  Any time I adjust a bit, I must set/reset them all (shifting).
- right.

> 3. To code for this puppy, I will need a delay, clock routine of 5khz
>         a clock line low (for not yet determined amount of time)
>         a data send routine
>         a clock high (for a not yet determined amount of time)
; RESET shift registers (since 595 max freq if 20Mhz and
; PICs instrunctions execute at Fosc/4 no need for delays
; and I thing the relays won't sense these speed, but it they
; do you only have to integrate the command signals
; PIC pin - Resistor - Capacitor to ground - transistor base
; to get a hardware delay so the relays will bu munb to the fast changes)
bcf    srclr
nop
nop
bsf    srclr
;send data
movlw    .8                ; you have to send 8 bits
movwf    loopvar        ; variable for controling the loop
loop:
bcf    clock
rrf    outbyte,f               ; put bit to be sent in CARRY
btfss status,c
bcf    data
btfsc status,c
bsf    data
bsf    clock   ; put clock high
nop                ; wait a short while
nop
decfsz loopvar,f   ; if all 8 bites sent then get out you are donne
goto  loop
bcf    clock    ;leave clock low
return

You get away like this without any delay routine, clock routine (5kHz?) this
is the routine I am using in my project and it's tested

> 4. I only have to clock when updating register
- right

> 5. If I used 2 shift registers, I could use the same line for clock on
both
>         since clock by itself won't affect register.
- not quite right. If you are updating both of them in the same routine (you
obtain a 16bit shift register) you have common clock and reset. The
registers have to be cascaded in order to obtain this, but if you want two
independent 8 bit shift registers, you have to have separate clock lines
since the clock "moves" the data at the input to te "next" output. You still
can have common data lines since data without clock does nothing.

This is not "trouble" as you call it. It's experience and cost saving! Stick
on using only what you need and you'l have better and cheaper projects! PICs
with more pins have more functions and that means to you more trouble in
writting the code.

Hope beeing of some help,
Mircea Chiriciuc
EMCO INVEST

P.S. The wiring is the one I used and it seems OK to me.

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