Welcome to EPROM Hut!

Obsolete EPROM Services For Today's Vintage Aficionado

The elusive Intel 1702A is our speciality! ;-)
Many types of early EPROM (Erasable Programmable Read-Only Memory) chips from the 1970s are not readable or programmable using commercially-available equipment. I have suitable equipment, and I also stock working vintage chips. This is a small hobbyist-run service for the retro-computing community. EPROM Hut offers:
Don't spend $$$ on risky vintage equipment if you only need a couple chips!

I can work with most of the 24-pin EPROM chips right back to the the early 1970s, including the Intel 1702A (and the original 1702!), the 2704, 2708, 2716, and many more. (See below for list.)

Services Menu (2024)

All prices include the cost of return shipping in the US; substantial discounts for multiples. Again, cost of shipping to you in the US is included. This is not a profit-making enterprise :-)

How does it work?

Just send an email to order@eprom-hut.com and tell me what you need. I'll quote you the cost and send a PayPal invoice. I turn stuff around pretty quickly, but I am just a guy so if you have particular needs or timing please do ask up front.

What is an EPROM and why can't I do all this myself?

EPROM stands for Erasable Programmable Read-Only Memory, and they were the first kind of ROM chip that you could repeatedly flash/burn your own data into. They can be erased using a special kind of UV light (that's what the little "window" on the top of the chip is for) and programmed using special voltages and timings. The Intel 1702/1702A was the first such device, containing a whopping 256 bytes of storage, followed by other series with more space. EPROMs are found most often in early microcomputers of the 1970s to store ROM bootstrap and user program code. They also show up in other devices of the era such as pinball machines and disco light controllers (!).

EPROMs have been obsolete for decades. There are cheap modern devices that will interface with many later EPROMs, but never the very early ones. Why? Because the oldest EPROMs used very weird high voltages and strange pin configurations and were obsolete quickly. There's no market for a modern commercial device for them. So what people do these days is either build a homebrew or DIY programmer/reader, or try to source yet another piece of 1970s vintage tech that itself may need restoration. Both of these paths are a lot of work, I did this once so you don't have to. :)

What formats do you accept data in?

EPROM Hut can work with any of the following: raw binary files containing the bytes to be programmed; Intel hex format text files; Motorola s-record text files; or a text file containing only ordered hex data.

If your data is substantially different from one of these formats, I may quote additional cost for data conversion.

I'm looking for preprogrammed chips. What do you have in stock?

I always keep 1702As in stock. I also maintain quantities of other 27xx chips that can be purchased pre-programmed, including 2708, 2716, 2732, 2764, 27128 and 27256 variants. The programmed chips you receive may be from Intel or another manufacturer, may be NOS or used, and will always be verfied working. These will sadly not have the fancy gold and ceramic packages -- those scarce variants are prized by chip collectors (and gold harvesters).

I'm doing a restoration and a fancy gold and ceramic EPROM would look awesome on my board! Can you help?

Maybe! I happen to have a few impressive looking 1702As and others on hand. Please ask. You can also send in whatever chips you want programmed and I will erase, program, and return them to you.

Will the EPROM I get from you do what I want?

I can guarantee that the EPROMs you ask for will be correctly programmed with the data you send me. Unfortunately, I am not able to guarantee fitness for purpose beyond that, and you will generally want to understand the device you're trying to restore/fix/update and how it works. I love hearing about the interesting projects people are working on, so I'm happy to offer suggestions in figuring out what you need, but ultimately what will work for you is your call to make.

I want to program old EPROMs myself. How do you do it?

For the oldest chips I assembled Eberhard programming devices for my own projects and now that I have all that, I'm happy to keep it busy. You can build a programmer too (get in touch if you want the kit referral), but do be aware that it takes some effort and can be somewhat costly. Mostly makes sense if you (a) like the idea of the additional project and/or (b) need more than just a couple chips programmed. (Both were true for me, now here I am.)

I need some diagnostic or BIOS ROMs for my IBM PC 5150, 5160, etc. Can you help?

Yes, probably! I've helped a few people with getting the Ruud's Diagnostic ROM for early PCs programmed onto the requisite EPROMs. The 5150 requires the somewhat hard to source Motorola MCM68766C35 part, so I keep those in stock and do those at the same rate as the rare 1702As (above). Later PCs (5160...) seem to use more common parts that are less costly. I'm not an early PC expert myself though so I only ask that you be able to point me to the specific ROM image that you need.

What about later EPROMs from the 1980s?

I am happy to help you program nearly any type of EPROM. I specialize in the very early ones that are impossible to do without special equipment, but if you simply need a single chip programmed, it may not make sense for you to invest in a brand new USB EPROM programmer from e.g. Amazon. I have one of those, so feel free to get in touch with your small-batch needs. The one you want to look for to do these yourself are any of the Xgecu standard devices—the "TL866" and its relatives are very capable, supported by multiple platforms, and not terribly costly.

Can you help me recover data from a physically damaged EPROM?


Maybe! Some of the antistatic foam used in the 1970s has proven incredibly corrosive to the gold legs of early EPROM chips. The legs rot and weaken or dissolve completely, falling off at the lightest touch. This is a long-term chemical process that cannot be reversed, ruining otherwise lovely parts. These chips can no longer be used in the normal way, and will not make contact in a socket. However, it is often possible to dump out the data from a chip damaged in this way. I have developed some techniques and tools that I've had success with. If you have an EPROM with important data but rotted legs, get in touch. I'm happy to give it a shot!

I have other questions, or I'd like a quote or to place an order

Please send a note and ask at order@eprom-hut.com.

What is the full list of EPROM devices you are able to read and program?

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