Re: [hatari-devel] IKBD regression with EmuTOS

[ Thread Index | Date Index | More lists.tuxfamily.org/hatari-devel Archives ]


Le 12/02/2013 11:37, Eero Tamminen a écrit :
Hi,

On sunnuntai 10 helmikuu 2013, Nicolas Pomarède wrote:
On 10/02/2013 19:29, Vincent Rivière wrote:
Ok, EmuTOS will need fixing if $80 $01 really answers with $f1.
But that does not explain why it works fine on real hardware.

In Hatari, after the first start, the acia's clock is started only when
writing $96 to $fffc00. If you receive byte from the ikbd before the
acia is set, this will create the observed error under emutos (due to
the overrun). If you then reset Hatari, the acia's clock remains
initialized, so the ikbd will work correctly this time.

The ACIA's doc is not clear on the value of bits 0 and 1 of $fffc00
after a reset. From what you say, if it works on real hardware, then it
would mean that the acia processes serial data after the first start
(bits 0 and 1 would be 0 and clock divider would be 1).

Based on Vincent's mail on emutos-devel, real hardware in this case
was STE.  Does STE ACIA behave differently?

(It's also possible that somebody who has replaced his ROM chips with
EmuTOS might have modified his machine also in some other ways. :-))

No, it's the same ACIA.



Mail converted by MHonArc 2.6.19+ http://listengine.tuxfamily.org/