MPC60 SCSI board schematics

skylab001 wrote:There could be a little room to play with the size though. I'm laying it out in Eagle.

I think that to get it down to 14.5cm x 4.5cm, to fit in a small empty space next to the main PCBs in the lower section of the ASQ10 case, I will probably have to use surface mount ICs, rather than through hole. I could also hardwire the ribbon cables directly to the PCB, to save space, rather than using IDC headers.

I don't have any PCB layout skills/experience, but should probably struggle through the learning process at some stage, with some free layout software, to see if I can get it going.

Well for me the layout is the fairly easy part, I learned while working for a pedal company. I can't say I'm the best at it, but it's easy enough if you are just following a schematic or diagram. I know a bit about the parts and circuits from putting so many together, but I'm definitely not an EE. Once I have everything laid out for this, it wouldn't be too difficult to change/add parts and to switch to smd components. I could send you the files and you could play with them in eagle free.

So two last questions, the cap on the top(or to the right near the SCSI text) of the 5380, where does it go? On the top pic of the board it looks like it jumps over the ground plane and then goes nowhere on the bottom pic of the board? Any chance of a pic of the the board with the 5380 pulled?

skylab001 wrote:Once I have everything laid out for this, it wouldn't be too difficult to change/add parts and to switch to smd components. I could send you the files and you could play with them in eagle free.

I would like to give it a go, thanks.

skylab001 wrote:So two last questions, the cap on the top(or to the right near the SCSI text) of the 5380, where does it go? On the top pic of the board it looks like it jumps over the ground plane and then goes nowhere on the bottom pic of the board?

Looks like it is jumping over the ground plane, but the upper leg is connected to the ground plane.

skylab001 wrote:Any chance of a pic of the the board with the 5380 pulled?

Sure, will do so tomorrow, when there is more light.

skylab001 wrote:Any chance of a pic of the the board with the 5380 pulled?

On L5380PC SCSI Interface Controller...

Diode anode seems to connect under large IC to pins 27 and 31, then across to lower leg of capacitor that seems to bridge the ground plane, but which the upper leg is connected to the ground plane.

11 to ground.

Thanks for the last photo, I should have some time on Monday to finish this up. I'm going to look into putting a 50 pin on it instead of 25, we'll see. I'm going to take some time and check out the datasheet and see what I can come up with.

Sorry, checked the L5380PC socket again, anode of diode is connected to pin 27 and 31 of the socket, not pin 27 and 30 as I mentioned earlier.

SimonInAustralia wrote:Sorry, checked the L5380PC socket again, anode of diode is connected to pin 27 and 31 of the socket, not pin 27 and 30 as I mentioned earlier.

No Problem, I actually caught that after looking at the datashet Are pins 22,23,25 on the L5380PC connected to anything. I have them NC right now

skylab001 wrote:Are pins 22,23,25 on the L5380PC connected to anything. I have them NC right now

Yes, they seem to be NC.

With the SCSI board layout almost complete, I arrived at work this morning and opened my box with the 5380s, I discovered they were the wrong chips sent over from china...grrr. I've sorted the problem, I was able to find a different supplier that has a low qty of them, my issue now is they have a minimum quantity order and they aren't cheap, double grrr... considering my options.