joerg wrote:
... but be aware that you MUST have a real serial port on your PC. Since USB converters are causing mostly trouble.
I'm sorry, but this is part of the problem.
There is NOTHING wrong with USB interfaces. Or USB to serial interfaces.
That is, if the software that is driving the USB-serial interface is worth anything.
Yes, there IS some damaged software out there that only works on 'real' serial ports. But 99% the problem can be tracked down to one of 2 issues.
1) The software author wrote the code BEFORE there use 'virtual' serial ports for greater than COM1 and COM2. There may be nothing wrong with the serial port as such. Just that the software is 10+ years out of date with current technology. In these cases not only will you have trouble with USB-serial interfaces, but you probably also have serious issues with ANY and ALL serial interfaces that are 'beyond' the original COM1 and/or COM2 spec of the original PC-XT. That means PC-Cards and even add on cards. And even with some machines that DO have COM1 and COM2.
2) The software author wrote code using tools that limit what they can do with com ports and just hasn't upgraded. Writing programs with something like Turbo Basic... Or worse!
In both the above cases it's NOT the USB-serial issue, it's the programmer not knowing what to do issue.
To be honest, there IS an issue with USB-Serial usage that can turn around and bite you on the lips. USB devices can be more aggressive with power management and that can be a problem. For example, I have some stuff that uses DTR and other modem control lines. In practice, I was using DTR to hold power to a 1-wire device (a counter) and if I let the device go idle, my counter would reset and loose it's count. But once I built an exteral 'mux box' to talk to multiple devices with one port, and the mux box had it's own power supply that didn't turn off with power management, then the problem went away. Oh, and my software works fine at ANY com port, even up above COM100. (There are real simple tricks to use high numbered com ports, and if you hear a software writer say it doesn't work, then question the REST of what that writer tries to tell you!)
As to the original posters question... realize there are some '08 parts that support BDM. If you choose one of them, then you can pretty much use the same setups and tools for the 12 on your '08 project. My last '08 project I used the MON08 interface, and it's not bad, but not close at all to the BDM setup I use with the '12. Just for the interface connections... In my case, I made my '08 board so that it had .156" card edge fingers and I just 'drop in' the card to a connector to program/debug it. It's only a credit card size, so that was a simple option, especially since I used a real simple '08. If I had to do anything more complex at all, I'm choose an '08 variant that supported BDM.
Mike