18 Feb
2016
18 Feb
'16
12:03 p.m.
Peter,
I confirmed that there is a NCR5380 chip on the daughterboard and that
everything was connected. Still no joy. The one thing I'm wondering is
this. If you look at the attached picture below from
http://home.iae.nl/users/pb0aia/vax/vs3khw.html, you will see there is a
40-ish pin EPROM (?) in the bottom row of chips third from the left. Mine
just has an empty socket there. Is it possible this is causing the problem?
According to the printset (which I am pretty sure I got from bitsavers), there
should be a 64K*16 bit 40 pin EPROM on the disk controller daughterboard.
What it contains I do not know.
It does appear to be an EPROM rather than a microcontroller (which was my
first thought when the idea of a 40 pin package with a quartz window was
mentioned) so it should be possble to copy one from a working machine, given
a suitable programmer.
-tony