I have a need to replace an ancient, long obsolete Hitachi microcontroller in a Uniden radio, it's one of the HMCS400 series, specifically the HD4074016 variant.
I believe these are a pretty simple EPROM based device, hold a couple of lines low in an adapter and it functions like a simple 27Cxxx EPROM for a programmer (I'd assume the algorithm would be similar to Hitachi EPROM algorithms but I'll research that more later)
The main problem I think I am likely to face would be sourcing a blank chip to program, there are lots of them listed on Ali etc. but none of the listings are very clear if they are new and blank or if they're just new and I assume the vendors will have no idea how to check anyway.
So, is anyone aware of a source of these chips that can guarantee they're new and unprogrammed? Is there a later, code and pin compatible version or an eraseable version?