Quote:
Originally Posted by _dx
I don't think you need this. Entering ISP mode is very easy and its done in few steps. But quality of bricked devices will be to high anyway.. I have some experience... Definitely we need parallel writer to develop firmware from scratch.
I am ready to develop custom firmware with almost any possible 5725 features and settings available from OSD, but i need community donate to buy parallel writer.
If anybody interested in this project and ready to donate - please let me know.
I need about $350. Or LabTool 48UXP programmer(may be someone have one)
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No I do not think you need the parallel programmer. I've loaded code at the end of the OFW by creating a jump branch.
There is a brick risk with the initial flash, but after that you don't need to mess with ISP code path. You can just write after the ISP check.
I've disassembled the original firmware in IDA Pro and have found the ISP initialisation and can simulate assembly in S51 simulator in the SDCC pack, then flash it to the chip no problems. You could buy 10 GBS boards for $350.