Jidis Posted June 8, 2005 Report Share Posted June 8, 2005 Hello,I've been sitting on a Greg Macmillan MB64 board for quite a while, and have finally started to set it up for a cue controller at the studio. The board is poplulated now, but with mostly empty sockets. I've blown the old firmware into an 877 (I'm running the 20MHz crystal too).A couple questions-I didn't have a BC337 on hand (I think it's in the LCD area) and a web search stated the 547 and a 2N2222 as subs for something. I had a 547 here. Is that OK, or should I try to dig up the 337? (most everything around here is 2N transistors)Is there a safe "one at a time" startup/test procedure for the IC's and what is the minimum that the firmware will function properly with? I doubt I will need all the ins and outs, but the sockets are all there. I've also left the connector holes empty for now. I'm not sure if I'll use headers or solder direct and I don't want to make too much mess until I know.                                 -Thanks All ! Quote Link to comment Share on other sites More sharing options...
raphael Posted June 8, 2005 Report Share Posted June 8, 2005 a web search stated the 547 and a 2N2222 as subs for something. I had a 547 here. Is that OK, or should I try to dig up the 337? (most everything around here is 2N transistors)Why don't you use a 2N3904?It's mentioned as a good replacement in the part list: http://www.ucapps.de/mbhp/mbhp_core_orderlist.txt547 is not good for higher currents (Icmax=100mA). BC337 is 500mA max.Is there a safe "one at a time" startup/test procedureDon' plug the ICs and measure all the voltages like described on the core page: http://www.ucapps.de/mbhp_core.htmlThen plug the PIV and try to get some MIDI signals. Pay attention to the different bridge connection from SC/J4 to Pin 22 instead of Pin 28.Btw: You should definitely change to the 18F PIC!!! Quote Link to comment Share on other sites More sharing options...
Jidis Posted June 9, 2005 Author Report Share Posted June 9, 2005 Raphael,Thanks! I had loads of 3904s. It looks like he even had the layout done to the pinning of the 2N part. I checked my voltages first and it all appears to work display & firmware-wise. It appears my 2x16 LCDs use pin 16 for the backlight (+) line. I thought that was 15, but it didn't hurt anything.I have to read up on which of the socketed chips are going to what, and how many I can remove. I'm also planning to use a 2x40 display, so I need to see how the stuff shows on the screen before I can arrange my knobs,etc.I do plan to probably switch to an 18F PIC. I Dremmel'd the 40pin socket around the crystal, so it's nice and easy to remove. This box is hopefully just doing send levels for some cue lines. I'm going to try to do a main controller afterward, which will likely use the MBHP type boards.                                      -Thanks Again!George Quote Link to comment Share on other sites More sharing options...
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