What debugger can you use on a DOS procted mode program?

I have a program written in CA-Clipper 5.2 and linked with Blinker 7. I recently learned how to compile it into protected mode in place of real mode. Now the real mode debugger won't work with the program. So now I need a way to debug my code. The documentation for Blinker says to use "NuMega SoftICE" or "Periscope". I'm not family with those debuggers, and can't find much on them 开发者_Python百科from Google. It sounds like SofeICE was turn into some type of hacking tool. Any suggestion on a way to debug my program?

NuMega was bought out, and SoftICE was killed (something like five years ago, if memory serves). It was a kernel debugger, which is a kind of tool some hackers (in either sense of the word) find useful, but wasn't really a hacking tool as such. (Silly trivia of the day: people who beta-tested the original version of SoftICE for Windows NT got a T-shirt that read: "...and they said it couldn't be done!").

Periscope is (was) an in-circuit emulator. It was a board with a plug to fit into your CPU socket, and a socket where you put the original CPU. It would then monitor all the traffic over the CPU bus, providing a lot of debugging capability that most software debuggers can't even hope to match. As CPU buses got faster, however, it got extremely expensive, and eventually got to the point that there was no market left. There was definitely a version for the 486 (I've used it), but I don't think there was ever a version for the Pentium or newer.

As to what you would use: the HX DOS Extender is probably the only DOS Extender still maintained. Their page lists debuggers that can be used with it. I certainly can't guarantee compatibility with the DOS extender you're using, but there's at least a chance one of them might work.

try watcom debugger with commandline startup: wd /tr=rsi trap for rational systems dos extender be sure to get latest version: open-watcom-c-dos-1.9.7z it has problems doing search but earlier versions do not work well