> > > So i was wondering, is there a way to see when to move the sprites
> > > (maybe by use of vrt retr.)? I assume there is because most games i
> > > played don't have this icky movement :-)
> >
> >You can read bit6 of VDP status register 2 to find vertical retrace:
> >VDP(-2) and &H40
> >
> >I forgot whether zero or non-zero means the vertical retrace is active.
>
> It's SET during retrace.
>
> >But I'm not sure BASIC is fast enough to react to vertical retrace...
>
> The problem is, as soon as the retrace starts the normal interrupt kicks
> in. If the BASIC interrupt routine (RST 38h) is fast enough to be
completed
> within the retrace (or blanking) period, you have a chance you can still
do
> stuff.
I think Kun-Basic / NestorBasic is fast enough.
> On the other hand, maybe it's better to use a ON INTERVAL command. I'm not
> sure how it works, but if it's interrupt driven it might be faster than
> checking S#2 bit 6. Besides, I don't even know you CAN read S#2 in BASIC
> since the interrupt routine always expects S#0!
You can, A=VDP(-2) will do the job.
~Grauw
--
>>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<
email me: [EMAIL PROTECTED] or ICQ: 10196372
visit my homepage at http://grauw.blehq.org/
>>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<
****
MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED]
and put "unsubscribe msx [EMAIL PROTECTED]" (without the quotes) in
the body (not the subject) of the message.
Problems? contact [EMAIL PROTECTED]
More information on MSX can be found in the following places:
The MSX faq: http://www.faq.msxnet.org/
The MSX newsgroup: comp.sys.msx
The MSX IRC channel: #MSX on Undernet
****
