Meaning, of course, the switch of the internal RAM block from data space to program space, or both. I'm a believer in starting with small steps and one at a time.

You say,"The program spits out {HI'0x0'.} which only shows up as HI because the terminal program truncates at the end of a string."

What does the terminal program interpret as the end of the string? When you say it truncates, does that mean that if you send it 10 characters it deletes the last 3, or what? How does any of that lead you to the conclusion that the XRAM block isn't functioning? IDE drives are RAM buffered, and, in any case, even the pre-buffering type are loosely coupled so you can fetch the data at any rate between the access time of the buffer RAM and two or three fortnights per transfer. There's no rush.

Why are you using 32 MHz? Is there some reason for that? Apparently the "bootloader" will autobaud to 9600 baud from 24.00 MHz. Is there some timing constraint that causes you to use 32 MHz, or was that just the only crystal or oscillator you had available?

I don't know SBCMON but that sounds like it's on the order of what I meant. I had ULTRAMON51, which allows assembly and disassembly in mind, but you could use pretty much whatever you like. The reason is that you can "manually" examine/modify SFR bits with that one, and I suppose many others will do the same.

You ask, "I guess I don't understand the "no path of retreat to safe ground". What is there a need to retreat from? I've tested as I've built (yes notably except for the SRAM but I didn't decide to use that till later)."

What I meant, of course, was that you provided no safe ground to which to retreat. That would have been provided by the 35-cent socket. As it stands, you have no easy way to determine whether there's a fault in your circuit or in your MCU. If you had another 8052 application, you could extract the MCU and drop it in there. When I have a couple of hours to myself, I'll do just that with one of the '420's that I have, in order to download the code snippet to which you referred, just to see what it does. I, of course, don't use a terminal emulator, but, rather, a terminal. That will change the landscape somewhat, but we'll see what that reveals.

Free PCB's for what? There are lots of guys who'd like to have someone else do their work for them. Be sure you're justly compensated for your part of the work.

RE