Subject: Re: Problem with serial I/O with GVP
To: None <>
From: Max Leung <>
List: amiga-dev
Date: 03/31/1994 23:54:38
On Mon, 28 Mar 1994, Max Leung wrote:

> I installed the latest generic kernal (vmunix.generic.940325), and now 
> find that whenever there is disk activity, serial I/O gets mangled!
> This never happened with the 744 kernel (with DMA off).
> When I turn off DMA, the serial I/O doesn't get mangled as much. With DMA 
> enabled, I get download errors every 4 or 5 K. Seems like when rz flushes 
> the data to disk, the corresponding disk I/O corrupts the serial line.
> This sounds like the infamous GVP-controller-trashes-serial-I/O-because-its-
> priority-is-too-high bug I've seen on the AmigaDOS side.
> Is there a way I can fix this, without recompiling the kernal?
> (I have an old GVP-Combo, 22 MHz, 13 megs of 32bit RAM, in an A2000 with 
> 1 meg chip. The only other board I have in it is the A2232 serial I/O 
> board, which does nothing under NetBSD. :-) )

I tried turning off everything, including setting _gvp11_dmamask to 4K 
(instead of 64K), turning off the gvp bounce buffer, and turning of scsi 
dma, but I still have serial I/O problems? Is there a fix?

Please help! I haven't got a response to the above message. I'm wondering 
if anyone is receiving it...

I'd really like to get serial transfers to work. Otherwise, I can't use 
Term nor can I use my Amiga as an X server for remote clients!

> Thanks,
> Max Leung
> ---------------------