Subject: Differentiating GVP DPRC products
To: None <>
From: Russel Miranda <>
List: amiga-dev
Date: 03/09/1994 01:51:37
Since I haven't had time to work on this myself, and it is something 
driver writers have been looking for, here's what I discovered:

I talked with someone I know who works at GVP, writing (of all things) 
drivers. I knew that it was possible to differentiate DPRC products by 
means of an "extended product code," which is how GVPinfo does it. What I 
didn't know was where to find this code.

He said that you just read the word at offset 0x8000. It contains 
information on which product it is, sometimes revision information, and 
the status of the jumpers on the board. I know the information on the 
product is contain in the lsB of this word, but I think he said it's only 
4 bits long. Here is what I get when I read the whole word on all my 

Ext Prod @ 00e98000: 14b7
Ext Prod @ 00ea8000: 14ff
Ext Prod @ 00eb8000: ffff
Ext Prod @ 00ec8000: ff9b

The first is my 50MHz accelerator, the 2nd is an HC8, the 3rd an HC, and 
the fourth is an IOextender. From what I've been told, the HC8 and HC 
are identical, except that the HC8 has RAM sockets and the HC does not. I 
think we could probably use this information to A) let the SCSI driver know 
whether it can DMA into non-zorro memory, and B) tell a serial driver 
about the IOextender. All we need to do is figure out which of the bits 
is the product, and then come up with a comprehensive list of them.

Can anyone else check these locations on their GVP boards and see if 
their numbers concur? It should work on all Series II boards (any board 
with a DPRC chip).