A/D Driver on 4.2bsd

[cheong at uiucdcs.UUCP]

I am writing a driver for an Analog to Digital converter, DT1711
series from Data Translation, Inc. The driver is written on Unix 4.2bsd
on a VAX 11/750. I am having a TIME OUT problem when I start the convertion
process. According to the manual for the series, the TIME OUT bit in the
control status register is set because non-existant memory was addressed.
I get the buffer address by doing the following:

/********* /sys/vaxuba/ad.c ******/
struct buf *bp;
int sc_ubinfo[2];
short dmacar; /* dma current address register, it needs a memory 
                 location to put the data in*/
*************/

         bp = geteblk(512);
         sc_ubinfo[0] = ubasetup(ubanum,bp,UBA_NEEDBDP);
    ==>  dmacar = sc_ubinfo[0]; 

Am I doing this right? Or what address should I give to dmacar? I would
appreciate very much if someone could give me some help. Thanks in advance.


-----------------

			Infan Cheong
                        University of Illinois at Urbana-Champaign
                        cheong at uiuc.ARPA