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For Sale: HP-71B MultiMod ROM Emulator
03-21-2021, 12:53 AM
Post: #16
RE: For Sale: HP-71B MultiMod ROM Emulator
There are a few vulnerabilities in the serial monitor code, none of which I thought would result in an unrecoverable change. Wrong! There is one case (not using Xon/Xoff) in which the default ROM Configuration Table stored in flash could become corrupted. This default is written to RAM each time the processor is reset, and can't be fixed with regular monitor commands.

Luckily I have an undocumented way (other than the boot loader) to update flash via the serial monitor. This was meant to be a platform independent means of updating the ROM emulator code without using the Windows-based boot loader client. I've used this update method to patch a corrupted ROM Table back to its initial default configuration.

I'm updating the documentation to reflect this problem and how to recover. The repair file is available in the DAT directory in the github repository. The recovery procedure will be used to update the ROM emulator software itself when new revisions are available.

I'm sure both Diego and Hans have their stories of teething pains with first releases. I'm *pretty* sure there's no other way to break things, but we'll see. Meantime, save your serial port settings in TeraTerm or other terminal emulator so you start out clean.

~Mark

Remember kids, "In a democracy, you get the government you deserve."
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RE: For Sale: HP-71B MultiMod ROM Emulator - mfleming - 03-21-2021 12:53 AM



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