[Coco] 128K EEPROM Cartridge board

[Chad H]

I was browsing prices on the 2764, 27128, 27256 and 27512 EPROMs this morning noticing how they are slowly getting more scarce, especially the 27128.  Also, the prices are not the best.  Ironically, at least to me, the 27512's with most capacity are the cheapest.  

Then I remembered I had a box of like 20 or so 29EE010 EEPROMs that I had ordered a few years ago. I only needed one to upgrade my Win'98 machines bios chip but was cheaper to buy the lot.  In any case, these are 128k parallel EEPROMs 150ns in the DIP 32-pin package and go for about $1.70 easy.  Even better, I can get the PLCC version for $0.25.  I know my old Willem programmer works with them and I wouldn't have to wait on UV erase cycles.

I have the idea of revamping the 2764-27512 EPROM boards I've been building, removing the existing DIP layouts and adding the option to mount either the DIP or PLCC version of the 29EE010.  I would also need to add one additional jumper for the A16 address line.  This would give more capacity for roms , each selectable by jumpers...

16 x 8K
8 x 16K
4 x 32K

I'm going to go ahead and work up some prototypes on this.  I'm wondering how much interest would there be out there in this?

- Chad

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