How to hook a logic analyzer to an Atari

[+Propane13]

Hello all,

 

I've been programming a 7800 game called "Get Lost" (there's info about it in the 7800 forum), and I've hit a point where I need to do some debugging on actual hardware.

Since the 2600 and the 7800 are very similar, I thought it would make sense to query all of the hardware gurus in this forum about what would be required to hook up a logic analyzer to the 2600 / 7800, and if anyone has ever done this. I'm guessing that there might be a bigger knowledge base here, since I've seen tons of weird 2600 hardware projects come out of this forum.

 

So, to start, I found this interesting ppt:

http://www.atariarchives.org/dev/CGEXPO01.ppt

Seems it was written awhile back, and the presentation mentions that back in the day, a HP-1600 logic analyzer was used (which I assume supports 6502).

 

For all of you hardware folks out there:

1) What type of logic analyzer would you recommend me purchasing / scrounging in order to test on an Atari 2600 / 7800?

2) How does one hook these up to "sniff the cartdridge"? Do I need to make a special connector between the machine and the cartridge? If so, how would one recommend doing that?

 

Any help would be appreciated; I'm not sure if anyone has done something like this before.

 

Thanks!

-John

[+batari]

Basically any logic analyzer that will run a few MHz or up will do (which is probably just about all of them.) They are designed to operate on arbitrary logic but that includes address and data buses like you find in the 7800. Last time I checked, though, logic analyzers were pretty expensive, even the really old, slow ones. The ones I used allowed things such as setting triggers (like a certain address or data sequence) and they would then record data at a specified clock rate, or something.

 

It's worth mentioning, though, that we have used Harmony as a logic analyzer. Basically it detected address changes after a specified trigger, and reported the contents of the address and data bus, and when memory filled up, it would dump the contents over USB using a terminal program. I'm sure the same sort of functionality could be extended to Harmony 2 when it's done

Edited July 27, 2012 by batari

[Pioneer4x4]

... I'm sure the same sort of functionality could be extended to Harmony 2 when it's done

Ah, another hint of Harmony 2? Or have I missed something?