Just a Simple Cartridge Port Probing Adapter

db-electronics · Post by **db-electronics** » Thu Nov 13, 2014 3:56 pm

I made a simple pass-through cartridge PCB to facilitate probing cartridge signals using an oscilloscope or logic analyser. All signals are labelled on both top and bottom silkscreen. It'll also permit to easily inject signals in into the console (i.e. from an FPGA dev board).

full write up here:
http://www.db-elec.com/home/lab-posts/s ... evhardware

Jazzmarazz · Post by **Jazzmarazz** » Thu Nov 13, 2014 4:02 pm

Hey db, looks nice. Reminds me of the probe board I made for gameboy....sadly these things don't want to sell.
http://store.kitsch-bent.com/product/kk_gb_brkout

db-electronics · Post by **db-electronics** » Thu Nov 13, 2014 4:05 pm

Jazzmarazz wrote:sadly these things don't want to sell

I know, the main intent is definitely not to sell, but I figured I'd post it here in case some people would need one (I know I need one!)

Jazzmarazz · Post by **Jazzmarazz** » Thu Nov 13, 2014 4:14 pm

Indeed!

HardWareMan · Post by **HardWareMan** » Fri Nov 14, 2014 6:03 am

I've made my own:

It's made specially for Altera DE0 board and use 2 IDE ribbon cables.

bastien · Post by **bastien** » Fri Nov 14, 2014 9:52 am

You use it directly without level shifter ?

HardWareMan · Post by **HardWareMan** » Fri Nov 14, 2014 2:47 pm

bastien wrote:You use it directly without level shifter ?

Yes. Not a serial design.

bastien · Post by **bastien** » Fri Nov 14, 2014 3:17 pm

I don 't think FPGA cyclone III I/O pins are 5V tolerant.
Maybe i don't understand your goal or your cart isn't complete ?

db-electronics · Post by **db-electronics** » Fri Nov 14, 2014 3:21 pm

bastien wrote:I don 't think FPGA cyclone III I/O pins are 5V tolerant.
Maybe i don't understand your goal or your cart isn't complete ?

You can't input 5V directly to a Cyclone FPGA, but the chip design allows for a series resistor on 5V inputs to limit the current flow in the PCI clamping diode. See this appnote from altera:

http://www.altera.com/literature/hb/cyc/cyc_c51011.pdf

That being said, not sure if the Altera DE0 provides those resistors.

Edit: the PCI clamping diodes are not active during configuration so you need to make absolutely sure to not drive any 5V signals in the FPGA until configuration is complete else damage could result.

HardWareMan · Post by **HardWareMan** » Sat Nov 15, 2014 4:47 am

bastien wrote:I don 't think FPGA cyclone III I/O pins are 5V tolerant.
Maybe i don't understand your goal or your cart isn't complete ?

You shouldn't understand this. Continue with your own. And yes, I've use some modified ribbon cables.

MintyTheCat · Post by **MintyTheCat** » Sat Nov 15, 2014 1:27 pm

HardWareMan wrote:
bastien wrote:I don 't think FPGA cyclone III I/O pins are 5V tolerant.
Maybe i don't understand your goal or your cart isn't complete ?
You shouldn't understand this. Continue with your own. And yes, I've use some modified ribbon cables.

Yes, Hardwareman seems to like to live dangerously and he has some odd ideas about handdrawn schematics vs. those created using Schematic-Capture but each to their own....