Hello, >From the outset, I want to thank Steve Adolph and Philip Avery for their outstanding work on the MVT100 and REXCPM. The main reason for this email is to reassure folks that it is not hard to build one of these kits, even for folks like me who have experience with soldering but not for a while. It took me about 90 minutes to assemble the kit, and probably another hour or so of troubleshooting. So, a fun evening of work. :-)
The kit comes with a packing list of all the components and I spent quite some time making sure all the bits were there. Of course they were all correct and accounted for. :-) I started with the low profile components: resistors and capacitors. If I were to do it again, I would solder in all the resistors that were oriented one way (as in up-down vs. left-right) because I found that the leads on the solder side were getting tangled up with all the resistors installed. Same deal with the capacitors although there are a lot less of those. You'll find you have to bend the leads quite a bit to get them to line up; no big deal, just be careful. The solder pads on this board are not large; you'll find that you'll be wicking solder through the hole in the board to make the connection. The exception is the socket for the PIC; its solder pads are "normal" size. The voltage regulator goes in next; again, you'll be bending that center lead to make it line up properly with the holes. As before, be careful with it and you'll be fine. Next goes the socket for the PIC microcontroller. I found it easiest to just solder one leg in, then make sure the entire thing is properly seated, and then solder in the remaining legs. The larger parts go in last: the jumpers, which had the same problem as the socket: solder in one leg, then make sure they are square down to the board. Then solder in the remaining legs. Finally, the connectors: VGA, Composite, etc. Check your solder connections under a magnifying glass. At this point I decided to power the board up without the PIC installed. I wanted to make sure the expensive blue smoke stayed inside the parts where it belongs. A quick check with a multimeter to make sure all the voltages were as expected on the socket, and I felt confident to shut it down and with power off, install the microprocessor. I found that the LED was in backwards; a quick desolder and resolder job fixed that. Now for the big moment: plugged in the VGA connector, a PS2 keyboard, and the power via the USB/Firewire connector, and yes, I could see a startup message on the screen! However, I could not get any characters from the M-100 to show up on the screen, and this is where Steve's support shines through! A few emails back and forth and we found that: 1. Make sure you have a color selected in the VGA jumper (I did; I used green) 2. Don't bother to set the BAUD jumper on the board, but DO jump into settings and set the baud rate to 19200. 3. Press Shift-F12 on your PS2 keyboard (NOT the M-100) to jump to settings and set: - Baud rate: 19200 - Invert RS-232: 2 (INVERTED) Save your settings and exit. 4. On the M-100, jump into CP/M and Press LABEL, F3, LABEL. This will cause REXCPM to divert the console to RS-232. I had my M-100 connected via a standard DB9 to DB25 RS-232 cable with a gender changer on the DB-9 end. Keep using the LABEL, F3, LABEL sequence to cycle through the various options: M100, RS232, CASS. The option does not take effect until you press LABEL that second time to exit the setting. 5. On the MVT100 board, MAKE SURE you place a jumper on at least one RS232 pin; I used Rx-3. If you don't do this, your RS-232 port is not connected. You will be able to tell if it is connected when you see the activity LED flicker as you press keys. Per Steve, a flickering LED just means that the PIC senses activity, not that it understands any characters. 6. Another way to test is to use TELCOM on the native M-100. Set the comms parameters to 98N1E (19200 baud) and start a session. As you press keys, you should see the LED flicker and characters appear on your screen. All you veterans are probably nodding your heads and thinking: "Yep, we know all this" :-) but this post isn't for you (but feel free to poke holes in my methodology if you want :-) I hope this helps folks who are maybe a bit nervous about putting together a kit and troubleshooting any issues; don't be. There's plenty of help here on the mailing list. Good luck and have fun with it. Cheers, Bert
