[A83] Re: Printerdriver for the TI-83(+)
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[A83] Re: Printerdriver for the TI-83(+)
>> Looks good, but it's only neccesary because of size (you smallend it a
>huge
>> bit!), not speed, since it has to be slown down enourmously.
>
>You can use nop's (no operations) to slow down. Make sure to time the loop
Yeah, I calculated that I needed more than 500.000 nops between
communications.
>on the calculator you will be using so you can be sure that the timing is
>accurate. A good way to do this is to make a loop that will go for 10-20
>seconds, and time it with a stop watch (have it print a message when it
>starts/stops).
>
>The loop below has 20 nop's, which take 80 t-states total, and the loop
>control code should take an additional 22 t-states, including the jump,
>giving a total of 102 t's. Looping 1000 times would give 102,000 t's. If
>the cpu really runs at 6mhz, then that should be ~ 1/60 of a second.
Again,
>you will need to use much larger values and time it externally to be
>certain. It also depends on the kind of accuracy you need.
That's the problem. I don't know which accuracy a 2400 baud signal needs.
>It might
>actually take longer than the stated t-states, because of the prefetch
cache
>(I don't have enough technical documentation on the z80 to be certain of
>this).
>
> ld bc,1000
>Delay:
> nop \ nop \ nop \ nop \ nop
> nop \ nop \ nop \ nop \ nop
> nop \ nop \ nop \ nop \ nop
> nop \ nop \ nop \ nop \ nop
> dec bc
> ld a,b
> cp c
;shouldn't this be cp 0?
> jr nz,Delay
;hey, that's much better and more expandable than djnz!
>
>> ;I'm just starting asm coding (well, 6 months probably) so I don't know
>> ;many commands.
>> ;What does 'rr' do? Roll Right & bit?
>> ;This could be extremely useful, because if the bits should be rolled
>> ;left it can be done by changing one command instead of 8.
>
>Check out the help file that comes with Assembly Studio 8x. It is very
>helpful, and explains all the instructions.
... so it has a help file ...... :-~
Let's take a look at it! :-~
Thanks,
Ronald