TK50Z-GA EPROM

From: dave dameron <ddameron_at_earthlink.net>
Date: Mon Jan 18 22:44:41 1999

At 09:07 PM 1/18/99 +0000, Tony wrote:
>> Hmm. You're comparing CMOS with TTL. The traditional EPROMs are not TTL
>> but NMOS - very similar components (at the transistor level) to CMOS, but
>
>Were some of the early EPROMS PMOS? The 1702 might have been (the supply
>voltages look like PMOS supply rails), but it's not stated in either the
>Intel or NatSemi data sheets.
>
Yes, as well as National's (5203), as well as families like Intel's 1101,
4004, 4040, 8008, etc.
My guess back then = around 1974, was NMOS was not used (much) yet, so MOS
only meant pMOS.
Another giveaway would be the negative Vdd. It puzzled me for a bit that
some pMOS
chips had no ground (0 Volt) pin, a 1101, for example, ran off a 14 Volt
supply with the positive tied to 5 Volts so the pMOS outputs could drive TTL.
Am sure there were very many others such as the AY-5-1013 UART and 2513
(in)famous character generator...

One of Intel's last pMOS products was the 1103 1K ram. I seem to remember it
was marketed as a replacement RAM for various mini's. This is _only_ 25
years ago, does anyone have a system RAM board running with these?
(Connecting the thread for 100 year old systems.)
-Dave
Received on Mon Jan 18 1999 - 22:44:41 GMT