20 Oct
2016
20 Oct
'16
1:55 p.m.
Oh that blinkenlights panel is excellent! All
emulators should have
one! :-)
Yeah, isn't that fun? Once I got it running, I just sat and watched it
for about fifteen minutes while it ran our disk exercising program. And
then I noticed a bug. It apparently wasn't causing a problem but the
address line 00 was lighting up each time it did a DMA. That didn't
seem right. I looked through the Verilog and figured out what was going
on. It probably wouldn't have caused a problem, maybe, but I got to fix
it anyway. See? 'Dem blinkenlights are useful!
I'm not really into Qbus much but would probably
buy a
production example anyway. I'd certainly fork out for several Unibus
devices if you make them!
Our plan was to do a Unibus version of the same thing as a follow-on.
It ought to be reasonably straightforward.
One tip from someone with same issue in a parallel
endeavor (IBM
System/360 panel): they look much better and more authentic with 'warm
white' LEDs. These are the ones I'm using:
https://octopart.com/l5-n55n-fuv-sloanled-29855005
Yeah. You can see in this picture that the LEDs I picked have this
yellow lens. I was hoping that would warm up the output but obviously
it didn't. I looked through the list of 1206 and 0805 LEDs on DigiKey
and didn't find any that were obviously what I wanted. I'll take
suggestions from anyone. Or, I suppose, I could re-spin the board for
through-hole LEDs. I've actually come to prefer surface-mount though
and I'm hoping that one of these days I'll have my own pick and place
machine (or I'll talk our soon to exist MakerSpace into getting one).
http://pdp10.froghouse.org/qsic/indp.jpg
