14 Oct
2010
14 Oct
'10
2:23 p.m.
On 10/14/10, Eric Smith <eric at brouhaha.com> wrote:
Ethan wrote:
I was working from scratch, and was finding debugging to be exceedingly
difficult.
Indeed. I've done communication device driver work in the past - and
seen many kernel panics - it was fun back then - your terminal session
rhythm would go "off" as your process was no longer being serviced,
then there'd be the tell-tale chatter of the console printer reporting
the unhappiness followed by a 20 minute dump and reboot cycle. Some
things are better left in the past.
I never
got to the stage of having a reliable driver.
Ah. Out of curiosity, did you happen to write it from scratch or did
you have existing UNIX 5380 drivers to "borrow" from?
These days it would be somewhat easier as I have a
good
logic analyzer I could hook up to the MC68010. (An in-circuit emulator
would be even better.)
Something like that, I do happen to have (a Northwest Instruments
"Satellite" bus analyzer that can capture and store the last 4096 bus
cycles... it was $20K when it was new, but I got to keep it when the
company doors closed. I've found it quite handy for debugging
hardware and hardware/firmware issues. I haven't fired it up in a few
years - this thread reminds me I should check it - the sampler box is
no doubt fine, I'm sure, but the "head" is an IBM 5150 PC with an
ST225 - I'm anticipating stiction issues.).
-ethan