aotta wrote: ↑
Sun Nov 25, 2018 10:43 pm
i am working on 16bit podule version, i am missing only soldering resistors but i need some help for their values (for r8 to r31 ones) and i am not sure about j1 and jp3 role..
may be give me a little help IanS?
r8 - r31 are series resistors for the ide signals. Dave suggests they are essential if using long IDE cables, I generally fit DOM or CF adapters where the cable length is almost zero. Based on the circuit diagrams Dave posted, they should be about 68 Ohms, I fitted 56 Ohms on some boards. For the first batch of boards I didn't have these resistors on the board, and on the latest batch (not yet for sale) I've taken them off again (too much hassle to solder, and most people are using DOM's or CF adapters)
J4 and JP3 work together, so that in theory you can fit the board to a machine without a backplane. If fitted to a machine without a backplane (A3xx only), don't fit a jumper to jp3, and connect the red +5 wire from the power supply to J4. I didn't have a lot of success doing this with HCT chips, but if you use HC chips (74HC245 for U1,U3 and U4) it works well fitted directly to the motherboard without a backplane. If using a backplane, fit a jumper link to JP3 and don't connect anything to J4.
J1 is where you can fit a drive activity LED (looks like you've already added an LED in the picture), the circuit with two transistors, shameless based on Dave's circuit is to drive a bi-color LED. If using a single colour LED and it lights when it should be off, swap the pins over.