[A83] Re: 83+ Questions
[Prev][Next][Index][Thread]
[A83] Re: 83+ Questions
Self test does a few things. It does checksum the ROM; it's just a plain
8-bit checksum. It sums pages 0 through 08, then 18h-1Dh (78h-7Dh on the
SE), except the first 200h bytes of 1Ah. It also performs a test of all the
RAM, making sure writes stick. This is what it's doing when it starts are
zero and counts upwards for ever (actually, it's a 2 bit counter, so it'll
wrap after 65535). Each number represents a full check of the RAM and ROM.
It also checks your ID, to make sure it exists (you'll notice an ID Fail on
the simulator). It does the screen tests, and the keyboard test, which are
fairly self explanatory.
On the SE, it also does a quasi CPU speed test, testing the CPU speed
against the crystal timers. This is the number that you see displayed at
the beginning of the self test on the SE (the number of CPU clocks it takes
until the interrupt occurs. I forget what frequency it sets the crystals
to).
Hope this helps,
-Dan Englender
> >
> >Hm....maybe try a full reset instead of just RAM? How about Mode, Alpha,
> >S? Does that work on SE?
> >
> >(Does anyone know exactly what Mode Alpha S does?)
> >
> >Tom
> >
> It does a checksum on the ROM, I believe.
>
> - - Joe
>
>
> --------------------------------
> Joe Pemberton
> http://tiworld.calc.org
> --------------------------------
>
>
> _____________________________________________
> Free email with personality! Over 200 domains!
> http://www.MyOwnEmail.com
>
>
>
Follow-Ups:
References: