Serial interface specifics?

[arjepsen]

Hey.
Since I started my internship at Pascal Audio, I've had some freetime in my evenings, and I've gotten around to muck about with sniffing out the serial lines from the cpu unit to the console.

Does anyone have any specifics on the connection? baud rate, etc?

[Y-my-R]

I don't know the specifics, but here's an old post from Munkustrap about that:

viewtopic.php?f=7&t=1166&p=9270&hilit=baud#p9270

If I remember right (not at the console right now), then the ProBox allows you to set the Baud Rate for regular/double, for communication with the console, but I'd think that for "regular" operation to communicate with the Mackie OS (if that's the goal), I'd think you'd probably want to use the "regular" baud rate... so, 115200 according to Ralph's post.

[arjepsen]

Yeah.
My issue was that I thought I was smart... and hooked up a uart to the rs232 side of a communications chip on the brain board... so I got a lot of garbage, no matter the baud rate.
It got better when I choose the TTL side of things

[doktor1360]

Hey.
Since I started my internship at Pascal Audio, I've had some freetime in my evenings, and I've gotten around to muck about with sniffing out the serial lines from the cpu unit to the console.

Does anyone have any specifics on the connection? baud rate, etc?

This is the tech data for the DB25 null modem cable/connection involved :

https://www.eltima.com/articles/serial-port-pinout-guide/

If you've got a protocol analyzer available to ya, you should be able to suss out most if not all of what you'd need - depending on the exact requirements. Every pin isn't likely to be used... I haven't looked at the prints recently for the D8B, but I would think the DB25 pin connection(s) could be mapped from the schematics to the connector standard :



The clocks and primary data lines (tx & rx) are most likely gonna interest you the most from starting at square one. Just let me know if I could be of any more assistance as your press forward...

Peace

[arjepsen]

what I did, was solder three wires to each of the ADM232A chips, and hook a couple of usb - ttl cables to them, so that I can sniff the communication in both directions.

This way, I managed to capture the communication at bootup, for both the brain and dsp board.
Today I've been messing a bit with trying to put that info into a python script.
I got a crude thing up and running, but it seems I've run into the "trial version" thingie.... So I need to read back up on how it was hacked, and see if I can get around it.

[doktor1360]

what I did, was solder three wires to each of the ADM232A chips, and hook a couple of usb - ttl cables to them, so that I can sniff the communication in both directions.

This way, I managed to capture the communication at bootup, for both the brain and dsp board.
Today I've been messing a bit with trying to put that info into a python script.
I got a crude thing up and running, but it seems I've run into the "trial version" thingie.... So I need to read back up on how it was hacked, and see if I can get around it.

Kewlio... suggestion - you might wanna get ya a coupla 'chip clip' test clip adapters, alligator clip test leads and then have at it a little more of a sense of security. Soldering to the pins certainly works, but you run the risk of shorting something out (too much solder), burning traces open, etc... not fun and you could potentially ruin a pc board in the process..

But you knew it was coming, so ya know, here it is:
[Standard Mgmt Disclaimer] - "Your actual mileage may vary..."

\m/

[arjepsen]

yeah, but I managed to get it working.
I'm not that bad with a solder iron

But thanks for your concern.
I think I've managed to make a script that boots the brain side of things, even though there seems to be some complaints about "trial version limit".
I need to test a bit more to see if it matters.

[arjepsen]

Hmm... maybe the trial version stuff is actually the terminal program I'm using

[doktor1360]

I think I've managed to make a script that boots the brain side of things, even though there seems to be some complaints about "trial version limit".
I need to test a bit more to see if it matters.

I briefly looked at the schematics earlier, and the J26 connector on the Brain Board is where the data cable connection on the rear of the console integrates into the D8B hardware logic. That's the 'traffic cop' for everything, there's a series of 3 serial interface ic's (TL16C452's) providing all the throughput. You'll notice all the clocking and discrete support components, as is the usual for transistor type logic circuits of this nature...

Bueno on the boot script, ya got yourself a toehold.. keep the forum board posted...

Peace

\m/