🧵cont'd
6. now time to dump that norpak ROM. the underside read "jl27c512d/n331018". i am no @foone so it took me a few tries to figure out what it was. a quick web search showed that it was some variant of the 27C512 - a 512 kbit EPROM (that's 64 kbytes).
the software i use for reading/writing roms on my TL-866/II programmer is called XGpro. when you type in 27C512, you get about 30 different options for that rom.
i knew a few things about it: it's a 28-pin package, and a DIP socket. so that narrowed it down to 20 choices.
i had to go through every single manufacturer option, read the chip, and watch it fail about 10 times. i finally stumbled on the right manufacturer (since "JL" wasn't an option) ... it read properly using Texas Instruments as the manufacturer: SMJ27C512
#alextel #minitel #bbs