Reverse engineering a ROM DOS device

Question

I understand that my question is probably too abstract and complicated to answer OneTrueAnswer ©, but I hope that I can express myself well enough to get useful feedback.

I came up with an interesting device that has the following characteristics. (from http://www.motia.co.kr/product/product_03.asp ):

• 80386 Compatible Processor (Intel) 33 MHz
• SRAM 512KB
• 4 MB flash
• ROM 512KB
• Video 32KB
• 320 x 200 pixels STN LCD with backlight, with touch panel
• 3 RS-232 ports
• ROM Dos 6.2 OS

Of course, this is not iNexus-Pre, but it was free;). In any case, it should be integrated into the road and tracer operations installed in the truck console. Not for me. My goal is to bend this device of my own free will, linking it to an Arduino (or similar) to satisfy my lust for DIY projects. Come on, three serial ports and a touch screen make my eyes glow.

And although I proceed from some technical background, I must admit that I do not know where to start. I can do the same as turning it on and accessing its shell from a serial terminal, meanwhile, the display only shows: "Initializing the system. Wait a bit ..." and what is it.

Naturally, I tried to contact Motia to ask for an SDK, but I was quickly and elegantly rejected.

So, without further ado, I reveal my questions:

• First and foremost: is it worth it? I am ready to spend several days off on this issue, but, given my endless stupidity, I do not realize the difficulty of my search. If so...

• ... where to begin? I have never developed anything (at least at least) in DOS, especially with a graphical interface. I hope I can change that.

• What else can I provide you to help me fulfill my goal?

Each type of feedback is approved.

Thanks in advance!

Answer 1

Is it worth it? I am ready to spend several days off on this issue.

Absolutely not. It will be very painful, and you will learn much more by spending your time after purchasing a development board with documentation.

What else can I provide you to help me fulfill my goal?

If saving money is your goal, do an ebay search for “touch screen development.” Right now there is a $ 58 STM32 module.

Better yet, grab $ 89 Chumby for http://www.adafruit.com (no LCD).

If you really want to play with a microprocessor and spend less than $ 5, get a TI development kit at http://www.yourwarrantyisvoid.com/2010/11/05/ti-launchpad-dev-kit-for-under-5/ . p>

Answer 2

It is difficult to say too much without any details, I am not familiar with this particular platform, but I can try to offer general advice.

It seems to be something like an embedded PC. The BIOS will load (MS?) DOS from the flash drive. When DOS starts, it first loads the drivers through config.sys, and then starts autoexec.bat. You probably have some kind of custom flash drive app that knows how to talk to the rest of the hardware (LCD, etc.). Is flash in the slot? One way would be to try to read the flash and / or reprogram it. Have you opened a business? Are there any other markings on the board and / or IC - can you upload a photo?

If you want to use the LCD, you will need to find out how it is connected. If it's just a PC-compatible video adapter (which seems dubious because you don't see it much), then it's pretty easy to program. If this is not without documentation, it will be very difficult.

It seems that at least you will need to reprogram the flash on the board after you define the file system on it. Without documentation and without tools (?) It will be quite difficult. From a software point of view, you should find many free tools for developing PC / MS-DOS, but until you can deploy your software on this device and control its hardware sounds, like for more than a couple of days off, given that you have zero documentation. If you are very lucky when you open the case, you will find some clearly marked port where you can connect a PC monitor and keyboard and, possibly, even a floppy drive - some built-in PC boards have such.

Answer 3

I have used the built-in ROM-DOS before.

This comes from General Software Corporation.

You can use the PC on COM1 as a terminal. The default behavior is the serial console on COM1. The data rate is from 19,200 to 115200 baud. First try 115200.

Send a break to reset your device and control-C to abort autoexec.bat

I am not kidding.

This is probably an AMD ELAN processor; The specifications look like the device I filed the lawsuit to work with. I think I still have my own home board that we were tearing away from work.

A quick google for embedded DOS-ROM gets http://www.compulab.co.il/all-products/download/edos-man.pdf

You can program it using an old (dos) copy of Borland C or Turbo Pascal.

Iterserver has a hint version that is not 100% compatible with Microsoft DOS.