A Better Use For The AGP Slot, Decades Later

March 3, 2024 by Jenny List 25 Comments

For a while around a quarter century ago PC motherboards came with a special slot, a little shorter than the PCI slots which ruled the roost back then, and offset from them further into the case. This was the Accelerated Graphics Port, or AGP, a standard created to more quickly serve the 3D graphics cards which were then taking the world by storm. It was everywhere for a few years, then in the mid-2000s it was replaced by PCI Express and faded into obscurity. [Peter] has a Socket 7-based NAS with an AGP slot, and was left wondering whether the unused port could be put to a worthwhile purpose.

AGP is a superset of PCI clocked at 66 MHz, and usually benefiting from having its own exclusive bridge to the processor bus. Thus he reasoned that he could make an AGP to PCI adapter and it might work, as the right connections are all there. A hacked-together version was made by butchering two riser cards, and when a network card worked quite happily he knew he was on to something and made a PCB. There’s a caveat that it only works with 66-MHz capable PCI cards so not everything will work, but if you’re one of the very few people who must be in the market for one, he can do you a PCB.

We’d normally end with a link to a related project here, but we must instead congratulate [Peter]. As far as we can find, this is Hackaday’s first AGP hack, two decades later. Continue reading “A Better Use For The AGP Slot, Decades Later” →

DIY Geophone Build Performs Well

March 2, 2024 by Lewin Day 14 Comments

If you want to know what’s going on with the ground, geologically speaking, a geophone is a great tool to have. It lets you listen in on the rumbles and grumbles beneath your feet, and can give you great insight into matters of seismic importance. [mircemk] has designed a very capable geophone that’s simple enough for you to build at home.

The geophone relies on a mass suspended upon a spring inside a chamber, which as you might imagine, will move when shaken by seismic vibrations. The mass is in fact a plastic rod, fitted with an iron nut and a magnet on the end.

This is mounted above a coil, which is fixed to the base of the chamber. Thus, when the chamber is shaken by seismic activity, the mass moves relative to the coil, with the coil picking up the varying magnetic field as it dances around.

The YouTube video does a great job of explaining the concepts involved and how to practically build the device. [mircemk] has also had some other great projects featured on Hackaday before, too.

Continue reading “DIY Geophone Build Performs Well” →

Wire Wrap Odyssey: A 7400-series Homebrew 8-bit Computer

February 27, 2024 by Maya Posch 15 Comments

The Wire Wrap Odyssey's first Hello World from the CPU module, here hooked up to a logic analyzer in July of 2020. (Credit: Paul Krizak) — The Wire Wrap Odyssey’s first Hello World from the CPU module, here hooked up to a logic analyzer in July of 2020. (Credit: Paul Krizak)

As part of his computer science curriculum at Texas A&M University in the early 2000s, [Paul Krizak] took a computer architecture course on the basics of their functioning. This and being exposed to dozens of homebuilt computer projects inspired him to begin building his own 8-bit computer in 2010, which eventually grew into the Wire Wrap Odyssey. This name covers both the primary construction method chosen around 2019 in the form of wire-wrapped connections, as well the harrowing journey to reach this point with a functioning computer system despite many choices and setbacks.

The Odyssey CPU is an 8-bit microcoded design with 16-bit address bus, using mostly 74HC-series logic. A VGA graphics card is also part of the design, which can output a 640×480 text display, with character glyphs read from the system ROM (32 kB AT28C256). As for the RAM, this is an extravagant 32 kB dual-port SRAM (Renesas 7007), which also allows both the CPU and video card to use the same SRAM. Currently the system has four peripherals: a PS/2 keyboard controller, an RTC and timer (DS1511Y+), 82C52 UART and 1 MB of extended RAM, but an ATA port and parallel port are in development.

Perhaps the most impressive part about this product is the level of documentation, from the early stages including paper doodles to the current state of the system, including the GitHub repository for the software. [Paul] was also an exhibitor at the Vintage Computing Festival (VCF) SoCal recently with his Wire Wrap Odyssey, where he was able to show off the progress so far. Next year he hopes to visit VCF SoCal again, with the remaining planned peripherals implemented.

Classic Calculator Goes RPN, With New Brain

February 27, 2024 by Jenny List 7 Comments

In the era of the smartphone, an electronic calculator may seem a bit old-hat. But they continue to hold a fascination in our community, both when used for their original purpose, and as objects for hardware hacking in their own right. After their first few years when they were a rare and exclusive gadget, they were manufactured in such huge numbers as to be readily available for the curious hacker. [Suikan] has taken one of these plentiful models and done something special for it, creating a new mainboard, and a firmware which transforms it into a reverse Polish, or RPN, scientific calculator.

The Sharp EL210 and EL215 were ubiquitous early-1980s calculators without scientific functions, and with a VFD display. We remember them being common during our schooldays, and they and similar models can still be found on a trawl through thrift stores.

On the board is one of the STM32 microcontrollers and a Maxim VFD driver, and fitting it is simply a case of soldering the Sharp’s VFD to it, placing it in the calculator, and attaching the keyboard. The firmware meanwhile uses the orange C key from the original calculator as a function key, alternating between standard and scientific operations.

If you’re curious about RPN, we’ve taken a look at it here in the past.

The Latest Advancements In Portable N64 Modding

February 22, 2024 by Donald Papp 7 Comments

[Chris Downing] has been in the mod scene a long time, and his 5th GeN64 Portable is his most modern portable Nintendo 64 yet. The new build has an improved form factor, makes smart use of 3D printing and CNC cutting, efficiently uses PCBs to reduce wiring, and incorporates a battery level indicator. That last feature is a real quality of life improvement, nicely complementing the ability to charge over USB-C.

What’s interesting about builds like this is that it’s all about the execution. The basic parts required to mod a classic games console into a portable unit are pretty well understood, and off-the-shelf modules like button assemblies exist to make the job far easier than it was back in the day when all had to be done from scratch. We’ve admired [Chris Downing]’s previous builds, and what differentiates one mod from another really comes down to layout and execution, and that’s where the 5th GeN64 Portable shines. Continue reading “The Latest Advancements In Portable N64 Modding” →

Pi Pico Enhances RadioShack Computer Kit

February 20, 2024 by Bryan Cockfield 9 Comments

While most of us now remember Radio Shack as a store that tried to force us to buy batteries and cell phones whenever we went to buy a few transistors and other circuit components, for a time it was an innovative and valuable store for electronics enthusiasts before it began its long demise. Among other electronics and radio parts and kits there were even a few DIY microcomputers, and even though it’s a bit of an antique now a Raspberry Pi Pico is just the thing to modernize this Radio Shack vintage microcomputer kit from the mid 80s.

The microcomputer kit itself is built around the 4-bit Texas Instruments TMS1100, one of the first mass-produced microcontrollers. The kit makes the processor’s functionality more readily available to the user, with a keypad and various switches for programming and a number of status LEDs to monitor its state. The Pi Pico comes into the equation programmed to act as a digital clock with an LED display to drive the antique computer. The Pi then sends a switching pulse through a relay to the microcomputer, which is programmed as a binary counter.

While the microcomputer isn’t going to win any speed or processing power anytime soon, especially with its clock signal coming from a slow relay module, the computer itself is still fulfilling its purpose as an educational tool despite being nearly four decades old. With the slow clock speeds it’s much more intuitive how the computer is stepping through its tasks, and the modern Pi Pico helps it with its tasks quite well. Relays on their own can be a substitute for the entire microcontroller as well, like this computer which has a satisfying mechanical noise when it’s running a program.

Continue reading “Pi Pico Enhances RadioShack Computer Kit” →