MCM68764 EPROMs

[RWAP]

Is there any interest in some MCM68764 EPROMs ??

I have managed to find a small stock (25 off) but price would end up being about £15 each ....

Probably better just to use the EL-2364 Flash EPROM which we stock.... Why do companies that have stocks of these old components think they are going to sell them at ridiculous prices?

[RetroTechie]

Those are regular 8Kx8 UV erasable EPROMs, right? And possibly using 21 or even 25V programming voltage.

Why on earth would one pay £15 / piece for those, when equivalents are easy to find, starting as low as £1 / piece? (or even less). And why would one want to use that these days, when a 27C64 is equally cheap, and does the same but using much less power?

Or is there something special about this particular type EPROM that I'm missing?

[1024MAK]

Or is there something special about this particular type EPROM that I'm missing?

I haven't checked (currently on a mobile device), but am guessing that they are pin-out compatible with the ROM socket. Unlike the 2764 / 27C64 types.

Mark

[RWAP]

Yes, I believe that they can be used in the original ZX80 and ZX81 ROM sockets - they are 24 pin chips programmable at 25V and I understand have been used in the past for the upgrade to the ZX80 ROM

We do of course offer the EL-2364 FLash EPROM already (and for only £10 each)

[Moggy]

Or cheaper still the 2764's I got a bucket of for 75p each which nobody wants as they are 21 volt devices, luckily My Spectrum EPROM programmer loves them, a quick 2 minute rewire and bob's yer uncle so no don't think I'll be paying silly money for chips new or otherwise.

[zx80nut]

...just double-check the pinout of the socket matches the EPROM . The ZX80 is a bit non-standard (in EPROM pinout terms) - I haven't checked the 81.

EPROM and ROM pinouts

ROMPinouts.gif (17.11 KiB) Viewed 3840 times

Details are on my page.

Regards.

Grant
http://searle.hostei.com/grant/zx80/zx80.html