EPROM Coffee Table

Either in need of a coffee table or suffering a severe lack of upscaled electronics, [Darren] just finished up a great build for his living room. It’s a huge, scaled up version of a UV erasable EPROM with an infinity mirror in place of the fused quartz window.

[Darren]’s coffee table was inspired by an earlier build by the geniuses at Evil Mad Scientist. A few years ago, they built a 555 footstool that was scaled up about 30 times its normal size. Even at footstool scale, the 555 is still relatively tiny.

[Darren] is using a similar construction technique by forming the legs of the EPROM out of laminated plywood. Since this build is significantly larger, building the entire device out of solid, laminated plywood would result in an unwieldy and expensive piece of furniture. Instead, [Darren] constructed the legs and sides out of plywood laminations, covering the ends, top, and bottom with plywood panels. The result is a hollow EPROM/coffee table that’s still structurally sound.

If you’re a bit confused after counting the number of pins on the coffee table, you’re in good company. This is technically a scaled-up version of a 16-pin 0.600″ PDIP, something that a quick googling suggest isn’t historically accurate. Maybe there was an EPROM with a 4-bit wide data bus somewhere in the annals of electronics history, but we’re happy with saying that a completely accurate scaled-up ROM would be far too big for [Darren]’s living room.

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DIY UV Lamp Is the Cure for Nails and More

We must admit to wondering how Adafruit’s [Becky Stern] gets anything done with those fingernails of hers. They’re always long and beautifully painted without any chips, dings, or dents. As it turns out, she uses UV gel nail polish. It’s much more durable than standard air-dry polishes, but it requires UV light to cure. [Becky] bought a lamp to use at home, but it’s very bulky and must be plugged into the wall. She knew there was a better way and devised her DIY UV mini manicure lamp.

She really thought of everything. The open source 3D-printed enclosure includes a small compartment in the top for cuticle sticks, emery boards, and tweezers. The Li-poly battery is rechargeable over USB in conjunction with Adafruit’s PowerBoost 500c. The lamp itself is made from 30 UV LEDs and 100Ω resistors. [Becky] lined the inside of hers with silver sticky paper to help distribute the UV light evenly.

You know, this can also be used to erase EPROMs or to cure small DLP 3D prints. Do you have another use for it? Tell us in the comments. Introductory and partially hyperlapsed video after the break.

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Overhauling an IC Programmer

Willem IC Programmer

[NeXT] needed an EPROM programmer to work with chips from vintage computers. Starting with a low cost programmer, he built this custom IC programmer to handle all of his programming needs.

The device is based on the Willem 5.0e programmer. [NeXT] was not satisfied with the device, noting that it had to be carefully isolated from metal surfaces during use and required setting many annoying jumpers.

To solve these problems, he started off by dismantling the programmer. The IC sockets were moved to a daughter board, which could be mounted cleanly into the metal enclosure. Replacing the jumpers was a bit more complicated, a combination of toggle and rotary switches were chosen to make changing settings easier.

Soldering the boards together looks like it was not an easy task, with 200 solder joints needed to connect the sockets and switches. After debugging some shorts and dead connections, [NeXT] managed to finish the 1.5 year project right before his Christmas deadline.

Fail of the Week: EPROM Reading and Erasing

It may be a failure but it sure does look cool. [Scott Lawrence] had a fair number of EPROM chips on hand and decided to get rid of the traditional eraser and programmer in order to play around with the concepts using his own hardware. He was met with disappointment at several steps in the process. No worries though, each of these upsets sent him back to the drawing board and he learned way more than he ever would have if it had actually worked. It’s fair to say this failure was highly successful.

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Add features (that should have already been there) to an EPROM programmer


[Morten Overgaard Hansen] has a cheap EPROM programmer which he uses to program chips for retro gaming (among other things). He was surprised that although the device includes a 40-pin ZIF socket it seems to lack the ability to program 16-bit chips. He figured he could get it to play ball if he put in a little effort. Above you can see that a few add-on parts enabled 16-bit programming on the device.

If you look inside the case you may be surprised to find it uses an FPGA. [Morten] searched around and found a few others online who had been looking to stretch the functionality of these types of programmer. Specifically, he came across a Python program for this programmer’s bigger bother that already implemented the functions necessary to program the larger chips. He used it as a guide when writing his own programming application.

On the hardware side of things he needed to feed a higher voltage to the VCC pin, which is done with the boost converter seen to the right. He also added some jumper wires to manage the output enable signal. To make the whole thing modular he ordered a ZIF socket with long pins and soldered the alterations in place. Look closely and you’ll see two levers for ZIF sockets. The one on the right is for the original socket, the one on the left is for the adapter.

Atari 800 EPROM cartridge hack


[Chris Osborn] had an old Atari 800 collecting dust and decided to pull it out and get to work. The problem is that it’s seen some rough storage conditions over the years including what appears to be moisture damage. He’s read about a cartridge called SALT II which can run automatic diagnostics. Getting your hands on that original hardware can be almost impossible, but if he had a flashable cartridge he could just download an image. So he bought the cheapest cartridge he could find and modified it to use an EPROM.

When he cracked open his new purchase he was greeted with the what you see on the left. It’s a PCB with the edge connector and two 24-pin sockets. These are designed to take 4k ROMs. He dropped in an EPROM of the same size but the pin-out doesn’t match what the board layout had in mind. After following the traces he found that it is pretty much an exact match for an Intel 2764 chip. The one problem being that the chip has 28-pins, four too many for the footprint. The interesting thing is that the larger footprint (compared to the 2732) uses all the same pins, simply adding to the top and moving the power pins. A small amount of jumper wire soldering and [Chris] is in business.

2708 EPROM dumper

[Andrea “Mancausoft” Milazzo] has been restoring old equipment which often contain EPROM chips. He thought he was all set with an EPROM reader which easily dumped the data from 2716 chips and a few others. But he found that the hardware was unable to read 2708 and 2704 chips. His solution was to build a PIC-based EPROM dumper.

You may remember from some of our recent features that these chips are something of a ticking clock. They store program code and other information vital to the functioning of old hardware. Since they’re erased with UV light, years of exposure to ambient light can zap some of the data.

The specs needed to read a chip of this type are rather rudimentary. There are ten address pins and eight data pins. [Andrea] also needed a way to get data from the microcontroller to a computer for backup. He uses two more pins for this purpose, bringing the I/O count to 20. He went with  PIC 18F4610 and built the rest of the reader around it.