EPROM Programmer Adapter for 27C400/800/160 and 27C322 16bit EPROMS

Amongst Retro Gaming and Retro Computer enthusiasts, there is often a need to program relatively large 42 pin (and 40 pin) 16bit wide EPROM chips.

Often this requirement comes about due to a need to replace an original MASK ROM in 16bit devices like SNES & Sega consoles, and Amiga computers etc. No doubt, this also applies to various other cool Retro devices from the 16bit era.

There is a popular family of EPROM’s which are fit for this MASK ROM replacement purpose. This family utilise a pin-out that is compatible with MASK ROM’s of the same size, so in many cases they are a simple drop-in replacement.

This popular EPROM family includes:

27C400 – 4Mb, organised as 256K x 16bit in a 40 pin DIP
27C800 – 8Mb, organised as 512K x 16bit in a 42 pin DIP
27C160 – 16Mb, organised as 1M x 16bit in a 42 pin DIP
27C322 – 32Mb, organised as 2M x 16bit in a 42 pin DIP

EPROM Programming Challenge

The challenge is finding a reasonably priced programming solution for these devices.

Most of the popular “reasonably priced” EPROM programmers only accept devices up to 40 pins. EPROM programmers that support the above family of devices “out of the box” can run into the hundreds of dollars! Not particularly wallet friendly for most Retro enthusiasts or electronics hobbyists!

Here at Digicool Things we created an Adapter to work with popular “reasonably priced” EPROM programmers. Specifically, we targeted creating an Adapter for the hugely popular TL866 series EPROM programmer.

In addition, we also wanted to improve on EPROM Adapter designs that had come before. We did this by being the first to make use of the innovative Rotary bank select switch, for simple bank selection, avoiding the tedium of manually toggled DIL switches.

Also, our Adapter should work equally well with other 40-pin EPROM Programmers, but, more on that in the Compatibility post, linked below.

If you’d like one of these Adapters, you’ll find a Kitset or a Fully Assembled & Tested option, on our Tindie store:
https://www.tindie.com/stores/DigicoolThings/

The Fully Assembled & Tested Adapter is also available on eBay (Tindie is preferred):
https://www.ebay.com/itm/284550002479

Discussion

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