More progress, and I'm pretty much ready to take orders! I built two SIMM programmer boards today and they both work fine...woohoo!
I've got the control program working on OS X 10.7, 10.6, Windows 7, and Ubuntu Linux 12.04. Ideally I'd also like to make it work on OS X 10.5 and 10.4. I'll see how well Qt can handle it, but no guarantees. The software should work fine on older versions of Windows and Ubuntu. The bootloader firmware seems to be rock solid, so I am pretty comfortable sending boards out to people now (although it helps if you have an AVR ISP programmer just in case we need to change something in the bootloader later on). The board is unbrickable. If you flash bad firmware on it, it's OK because it always starts up in bootloader mode and then jumps to the actual SIMM programmer firmware after the control program tells it to. This is kind of strange because it will actually disconnect the USB connection, jump to the programmer board firmware, and then reconnect the USB the first time you talk to it after plugging it in, but that process seems to work just fine in every OS I've tried.
I anticipate we will run into minor glitches as the software gets tested on various people's setups, so if you're interested in one, be prepared to take some time to work with me to make it work.
I'm not mounting any of the RS-232 hardware right now -- just sticking with USB. This lowers the cost of the parts for one, and you need a USB port to power it anyway, so you might as well use USB to communicate with it. USB is faster than 115200 bps serial, which is probably what your serial port supports at max. Plus, I don't have any software written for the RS-232 port anyway
The cost of the programmer board is going to be $40. It's not so much the cost of the parts (about $15 per board and over half of that is just the microcontroller + PCB), but the labor it takes to assemble this beast. There are various small parts and some of them are crammed pretty close together, so it takes some serious time to assemble it all compared to the SIMM, which is easy because it's basically doing the same thing 4 times with very few parts.
I'll have binaries of the programmer software ready for download really soon, so you can at least open it and make sure it runs on your computer. The board will work out of the box without any drivers in OS X and Linux. Linux will need a small udev rule installed to set the serial port permissions though. Windows needs a very simple INF to tell it to load its built-in USB CDC modem driver.
Anyway, for everyone who's interested in a programmer board ($40 plus $5 shipping to USA), SIMM ($20 plus $5 shipping to USA), or both (combine the shipping together so you pay $5 total for shipping), let me know via PM so I can get an idea of how many programmer boards I need to build for the first batch. (I have several SIMMs already built up and ready to ship whenever, if anybody cares.) The programmer boards are easier to build in batches because of how many different parts there are to get out from my stash...
Remember, the programmer board will be compatible with any SIMM I built that has the red LEDs with olePigeon's graphic. The first board revision which did not have those is not
compatible with the programmer board.
Last but not least, THANK YOU
olePigeon for finding a source for the 64-pin SIMM sockets. All of the sockets I've tried so far have worked fine. Without you, this project would have been much more difficult to realize!