I want to have copes of all the roms on fusible-link prom so when the orignals go bad I have the code saved and the proms ready, I cant make roms so would need some help with that, my 4016 has one custom rom as it was used in a lab, the old roms were only ment to be good for 5 to 10 years and my ones are 31! years old,
Well, I'm not sure what MOS datasheet specifies the lifetime of the ROM's as 5-10 years but it's certainly inaccurate. The 10 PET's I've reconditioned over thet last couple of years probably contained 60 ROM's of which I had maybe 3 dead ones and by definition, they're all between 30 and 35 years old as well.
I think there's a better than even's chance that you're ROM's are still good and if they do need replacing then by far the easiest option is to buy a $6 adapter from JB and put an EPROM in it. Sure, EPROM's lose their contents over time but I have Commodore prototype boards which contain working EPROMS's burnt by Commodore themselves 30 years ago, so if you put new ones in now, they stand a good chance of outliving you (assuming you're a similar age to me!)
As already mentioned, it's more likely that you'll have problems with RAM, PIA/VIA's and glue logic.
a lot of electronic parts work a lot longer than destined for, and I want this computer to be working in 32 years, I have spare ram somewhere?