For about a year, I've been using AMD 2764 EPROMs for my cartridges. My programmer doesn't support very high voltages, and the AMDs can be programmed at 12.5V, which is perfect. And they're super-reliable; I've only had two go bad on me.
But my stock of these is dwindling, and they're getting more expensive. A year ago, I could pick them up for $1.50 (USD) to $2.00, as many as I wanted. Now, it's common to see AMD 2764s going for up to $6 with shipping, and I don't see the lots of 10 chips as much.
In response, I've started evaluating EEPROMs, the 28C64B. These cost as much as AMD 2764s were a year ago, and it's kind of nice not to have to erase them with UV. They seem to be able to replace the 2764 with no modifications, even on the original Commodore cartridge PCBs.
Are there any caveats to using 28C64Bs as direct 2764 replacements that I haven't observed?
AM2764 Replacements
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chysn
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AM2764 Replacements
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Mike
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Re: AM2764 Replacements
Not any that I am aware of. The 2864 EEPROM is supposed to work as drop-in replacement in any design that otherwise hosts a 2764 EPROM.chysn wrote:Are there any caveats to using 28C64Bs as direct 2764 replacements that I haven't observed?
Some more details here: ROM replacement options (split/OT from: WIP: MINIMON)
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chysn
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Re: AM2764 Replacements
Thanks... Heh, it seems like I asked this question almost exactly a year ago, in a slightly different way!Mike wrote: ↑Tue Jul 20, 2021 10:59 am Some more details here: ROM replacement options (split/OT from: WIP: MINIMON)
I guess I just didn't have the financial pressure to experiment with it before. I bought enough 28C64Bs to last me a few years, assuming modest sales growth with new cartridges.
Knowing this, I might pick up some 28C16s and try populating 8K (VIC-1110) cartridges again. I was never able to get an 8K cartridge to host a pair of 2716s. One, but never two.