On 28 May, Anders Magnusson wrote:

>> d/p/l 20088000 80000000
>> d/p/l 20088004 80000001
> This maps Qbus page 0 and 1 to physical memory page 0 and 1. Then you
> can put the correct values in the RXV registers and it will send its data
> to these memory pages.
Ahhh. Now I understand these controler setup magic. You have to setup a
QBus <=> RAM mapping for DMA transfers from the QBus to RAM. Then the
controller is a command given that loads some setup programm via DMA
into RAM and "S 80" or the like starts this setup programm. This is
clever. 

But what does: 
D/P/W 20001f40 20
Is this needed to enable DMA transfers? I found that DMA from and to
the RXV21 only worked after this. (But I may be wrong.)
-- 



tschüß,
         Jochen

Homepage: http://www.unixag-kl.fh-kl.de/~jkunz/