On 5/26/2016 1:41 PM, David Riley via vcf-midatlantic wrote:
On May 26, 2016, at 00:48, Dave McGuire via vcf-midatlantic <vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
Yup, "OTP" EPROMs. I think that's just called a "PROM". :-)
- Dave
No, from what I understand of the usual usage of terms, PROMS are the bipolar/fusible link parts like 82s137, MMI6301, etc. These can be open collector or tri-state. OTPROMs aka OTP EPROMs are floating gate 2764/27128/etc EPROMs with no window, so they can't be erased with UV light (though, as we can see here, age can still cause them to become slowly erased). Mask ROMs are the 2364/23128/etc parts which are mask programmed at the chip fab, and never lose their contents unless they lose their smoke. -- Jonathan Gevaryahu jgevaryahu@gmail.com jgevaryahu@hotmail.com