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Read DS89C420 as an EPROM

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Newbie level 3
Sep 14, 2009
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I have the above device and we suspect that it's been fried by static but have been informed that it might be still readable and thus we can flash another device to repair the item it came from. Looking at the datasheet it seems there a two main options

1. Read via an EPROM programmer
2. Create a simple RS232 interface and read directly from the chip's bootloader menu.

I would imagine that option 2 is less likely to work given that we suspec chip damage so I would first like to try option 1.

My father has a HILO Systems All 07c programmer which supports a huge range of devices but this item is not listed explicitly. How would I go about finding a similar device type that we might use to make a read?

If the answer is simply that that programmer won't read the device then could somebody point me in the direction of a budget programmer that would?

If you think option 2 is worth trying, I would still prefer to purchase a kit or ready made interface - can anybody suggest one?

Any help and advice is a appreciated.


go to maxim site , you can program using com port. details in data sheet. the software is available from the web site

Thanks but that doesn't really address my points.

If the device is locked (Memory is read/write protected), which I am sure is, you have no options left.
No manufacturer leaves the device unlocked these days.

Ok. So if we're working on the assumption that it's locked then I'll need to use my original option 2. I already have the Loader420 software, I've seen the schematic in the Help file and I've seen the PCB posted on this site but as per the original post I would appreciate it somebody can point to a place that I can purchase a kit or preassembled interface. Does anybody know if this is something I'm likely to be able to find?


Even bootloader will not be able to read the memory of a locked microcontroller. This feature is to avoid code theft.

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