6 Feb
2006
6 Feb
'06
8:39 a.m.
On 2/6/06, Don North <ak6dn at mindspring.com> wrote:
It's not clear from the above discussion from
9000vax as to what he used
for the bus receiver; he just describes using the 7406 as an output
driver on QBUS. Not clear what he uses on input.
I use ALTERA EPM1270 CPLD to receive QBUS directly. It has 4V absolute
max input level but I can enable the internal diode to limit the
possible voltage surge (in PCI pin compatible mode). I set the input
level to 3.3V LVTTL for a time and it worked OK too.
vax, 9000