@Moebius- Is that a verification that the character display chips are indeed only set to support a fixed group of characters? (just wondering)
Yeah, the MIDIMon is actually the main thing I made that for, but not for the LCD data monitor. I want to mess with some of Thorsten’s seven segment code and matrix displays, and learn about the shift register handling for it. 
I’ll likely be using it with no LCD for that stuff, but will have one around for the inevitable “emergencies”. :-[
It’s got a few pin headers on the bottom for the d.in/out and a.in mux lines, and a jumper block to hold the Bank A lines @5v, or take them to external pots or whatever. The LCD socket is just a cheap 16pin DIP socket, cut in half. I bottom-soldered it with the pins set a bit high, so I could get to the joints (still a PITA), then hot melt glued around it so it couldn’t move. Afterward, of course, I realize that my backlight pins don’t go +/- for 15&16, so I have to cut into the glue, shave out a couple traces, and jump them back in reverse. Is that a common occurrence with the last two pins on some LCD’s (may be worth a note on the LCD wiring PDF)?
One of those high quality “long-legged” DIP sockets would be best for the trace side wiring, but I only had 14’s here. >:( I’m thinking of moving to one of those nice looking PCB mount female header sockets for the LCD (the ones that look like the end plug of an IDE ribbon), and moving to a double-sided board, mainly just for those LCD traces. The PIC pinning, and the LCD location I used, puts a bunch of them in a really inconvenient order, so I just ran most of the traces for varying lengths away from the LCD socket, horizontally, and terminated them with pad holes, which jump down to the correct PIC pins with short wires on the top. It takes a few jumpers, but they’re in neat parallel rows and they’re ultimately hidden by the PIC (as are a couple caps and resistors, IIRC. The double-sided LCD traces and female header would make that a lot easier, but I figured if it worked, and I could refine it a bit, someone else here might like to make one for something, and I don’t know what most of you guys are doing for etching, or how much trouble D.S. boards would be. With D.S. traces there, you could land them directly over the area just inside the PIC socket legs and solder a short wire from top to bottom, almost as easily as laying a jumper.
Here’s the bottom view:
There’s a DPDT slide switch and a pin2 ground jumper at the back, which will turn the MIDI jack from an input to an output, for unidirectional MIOS devices, once the PIC’s contents are finalized. Output mode is actually a bi-directional dual pinning, where the outer two DIN socket pins carry the input lines (used with an adapter), or you can just run a standard MIDI cord for output only. I’m about to do a 5pin to 15pin male, for a direct gameport cable, and may also look into an LTC based “direct-to-COM” addition.
Still wondering about the 9V battery if anybody knows? There’s a pin header for a 5v output, but it’s post-regulator/filters, so maybe a couple holes somewhere else, for external battery wires would work.
does it fit in a box
Funny, I’d like to get it into something, so I can throw it in my bag, but don’t want it that much bigger. I thought about slicing a small chunk of 2x4 in half, and drilling out the insides for a small case like you mentioned. I’d also like it to be able to stay in there while I use it, so I guess I’ll need holes for the sockets. With the case in mind, it may also help to move the four mounting holes out a bit, with some empty border area, so it could screw down flat on something. Otherwise, I can always stick a couple scraps of foam on it, or wrap it in cloth, and secure it with a rubberband.
Sad part is, I now have a whole batch of portable MB devices I made, so I can carry them around and play with MIOS/app assembler code, and so far, I don’t appear to be carrying around anything. 8)
I was also thinking of doing modular “stacked” boards, with a header block at one end, and maybe a couple spacers on the other, along with a matching female socket on the bottom. That way, you could squash together a whole “brick” of core/d.in/d.out/a.in’s, or whatever, maybe with those five pin 90 degree headers on their edges for any external part connections. I guess a socketed PIC, or the heatsink/caps, might get in the way there, unless you used a taller “link” socket or pin header on the core, or a regular external LCD/cable with the PIC on top, or you could take the main core link to the first board with a short ribbon and 90 degree dual row headers on the edge. ???
BTW-- Anyone think the heat of a small box-enclosed core is worth considering? I thought about putting some extra room on the sides of the regulator, maybe for the option of using those “fancy-finned”, “bat” looking heat sinks.
Also, I might add a few easier direct connections, for a small number of optional buttons (or maybe even LED’s). Right now, it just has the usual (2) MIDIMon buttons, which pull the first couple Bank A lines to ground, and I left out the ICSP stuff (I’ll probably want that).
Can those two (or more) buttons on Bank A be easily configured to control the same MIOS functions of a regular “D.In” input, by shorting to ground on closure like that? It would help if I could work on button code without extra traces, boards, or shift registers, but I don’t want to work with code which will require a bunch of repatching to use in a regular box.
Thanks!
George
PS- @BpM- Sorry for the thread hijack, but I guess they’ve already shot down the inverted LCD idea. ;)