HP82143 Processor details

[blackjetrock]

(06-03-2023 01:31 AM)cruff Wrote:  I recall Steve Leibson told me in reference to the 98037A that the 3870 has no way to read out the contents of the ROM without decapping the chip and extracting it from the mask.

Yes, that is a very common situation. Sometimes there is an exploit that can be used to get ROM data, but a lot of the time a de-cap is the only way. I have done this a few times and have a metallurgical microscope to do the image capture. Sometimes the ROM contents aren't visible without layer removal, which I haven't attempted yet. Sometimes it is visible without further processing.

This is totally destructive so a dead IC and/or printer is the best donor device to use for this.

Andrew