The MPU doesn't respond to NMIB while reset is low, so it doesn't matter. If you want a truly warm and fuzzy feeling about it, you can insert an R-C network into the Vcc feed to the reset generator to extend the reset time a little bit, thus guaranteeing that NMIB will be high before the MPU comes out of reset.

Speaking of NMIs, your NMI handler should be written so it doesn't do anything if the MPU is executing code in your firmware when a "panic button" NMI hits. A simple stack sniff is all it takes.

_________________
x86?  We ain't got no x86.  We don't NEED no stinking x86!

So that order came in, the one the logic probe was supposed to be in. Unfortunately, that item was discontinued.
Another reason that I don't like to shop at Jaycar. They may be Australian-owned, but some of their stocking decisions are mind-boggling. They carry the standard 2.45mm pitch pin headers, but no pcb mount sockets that will match them(they have cable-mount IDC connectors), and no right-angle versions of either. They have those machined pin socket strips, which are good for ICs and thin leads, but I've hacked up one such pin header, and while it works, it's quite fragile.
I just moved back in to uni, and I've ordered a kit probe(this one: http://www.altronics.com.au/p/k2586-logic-probe-mark-2-3-state/). It does pulse-detection by the looks. I think I'll switch the high and low LEDs around, so that it's red=low. That makes more sense to me.

I did order some protoboards along with the original probe. I'll have to get some appropriate connectors to get that idea rolling, though.

However, it is opposite of industry standard.

_________________
x86?  We ain't got no x86.  We don't NEED no stinking x86!

Uh, make that 2.54, not 2.45. It'll be important if you lay out PC boards.

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

BDD: Really? I did not know that. I wonder why that is... I won't swap them, in that case.

Garth: You're probably correct there. I'd seen 2.45, 2.5 and 2.54 in various places. Whatever they are, they're the right spacing to fit into both the protoboards that I have used them on.

Low = true for a lot of select and enable lines like chip-select, write-enable, output-enable, etc. (which is why there's a bar over them, but phpBB software so far does not provide a way to write that), but obviously not for address and data lines where 1 is high voltage and 0 is near ground.

2.54mm is .100" which is the standard.

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

As Garth noted, chip selects are mostly low true, so green for low (think green for "go") makes conceptual sense.


Garth is not probably correct. He is correct. 2.45mm would be 0.096 inches vs. 2.54mm being 0.100 inches. The pin spacing difference between the two would accumulate at the rate of 0.004 inches per pin. If you were attaching a 10 pin header with two rows of five pins you'd have an error of 0.016 inches by the time you got to the other end. The header would be unlikely to fit the board, unless you use a big hammer.

_________________
x86?  We ain't got no x86.  We don't NEED no stinking x86!

Now if only DB-9, DB-25, RJ-11, RJ-45, PS/2, etc. were made to go into standard perfboard with .100" hole spacing!

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

Yes, he is correct. But I only know that now because I just ran that through a unit converter. Since I work in metric units almost all the time, I don't bother much with imperial.

I have the protoboards in front of me, but I still need the right-angle connectors to do much with them. I'll need to put in an order at Core for those, I think.

The four-port 8P8C (incorrectly referred to as RJ-45) "harmonica" I use on POC V2 has 0.100 inch (2.54mm) spacing on each row of pins. Unfortunately, one row is offset 0.050 inches (1.27mm) relative to the other. So it won't fit standard perf board without drilling a bunch of extra holes.

_________________
x86?  We ain't got no x86.  We don't NEED no stinking x86!

Just for the heck of it I ordered one from Ebay, at US $7.20, free shipping. Not as cheap as that discontinued Jaycar deal, but then again their super-low price was because they were discontinuing them - as you noted.
My LP-1 probe arrived a few days ago but I haven't had a chance to test it yet.

I would assume 2.45mm is just a typo. 2.5mm is a regular metric pin spacing. 2.54mm = 0,100" is regular imperial.

It is common practice to use a red cable for positive voltage from power supplies, black for GND, and blue for negative supply - e.g. +15V/0/-15V analogue supplies. I assume this convention causes the choice for red LEDs = positive voltage and (due to the lack of blue LEDs for many years) green LEDs to indicate negative voltages.

my 2 cents

Well, your two cents makes sense.

Not sure on the LEDs. The green = low, red = high convention has been around for as long as I can remember, at least back to when I first used a logic probe to troubleshoot a digital circuit, which was in the late 1970s.

_________________
x86?  We ain't got no x86.  We don't NEED no stinking x86!

I have built up the ACIA board. I can't confirm whether it works or not, because I haven't tried it yet. I've got a few basic routines written for it, and I've started on a very basic monitor(read, write, and execute commands). I haven't quite finished that yet.

On another note, I have ordered and received a logic probe kit. It's built around a 4001, and the instructions say it should be good up to around 3 MHz on the two 3V cells it's designed with, and possibly up to 9 MHz on 15V(I'm not sure it'd work for 5V logic at that point, though). I haven't built the kit yet; that'll have to come a little later, as I'm not at home right now, and I didn't bring my soldering iron. I don't want to set off the fire alarm with the flux smoke. Can't afford the fine.