Dealing With The 1970s EPROM Chaos In 2025

August 23, 2025 by Maya Posch 15 Comments

It could be argued that erasable programmable ROMs (EPROMs) with their quaint UV-transparent windows are firmly obsolete today in an era of various flavors of EEPROMs. Yet many of these EPROMs are still around, and people want to program them. Unfortunately, the earliest EPROMs were made during a time when JEDEC standardization hadn’t taken root yet, leading to unique pinouts, programming voltages, and programming sequences, as [Anders Nielsen] explains in a recent video.

[Anders]’s Relatively Universal-ROM-Programmer project recently gained the ability to program even the oldest types of EPROMs, something which required modifying the hardware design to accommodate EPROMs like Ti’s TMS2716 and the similar-but-completely-different TMS2516. Although not the hardest thing to support – requiring just a diode and resistor added to the BOM along with a firmware update – it’s just one of those pre-standardization traps.

As [Anders] put it, it’s sometimes good to be unencumbered by the burden of future knowledge. Who would have willingly subjected themselves to the chaos of incompatible pinouts, voltages, etc., if they had known beforehand that in a few years EEPROMs and JEDEC standardization would make life so much easier? Maybe that’s why messing with retro hardware like this is fun, as afterwards you can go back to the future.

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Amiga Programming In 2025 With AmiBlitz

August 10, 2025 by Tyler August 30 Comments

Having owned an Amiga microcomputer is apparently a little bit like having shaken hands with Shoggoth: no one can escape unchanged from the experience. Thirty-two years on, [Neil] at The Retro Collective remains haunted by the memories — specifically, the memory of BlitzBasic 2, an Amiga-specific programming language he never found the time to use. What better time to make a game for the Amiga than the year 2025 of the common era?

[Neil] takes us on a long journey, with more than a little reminiscing along the way. BlitzBasic may not have been the main programming language for the Amiga, but it was by no means the least, with a good pedigree that included the best-selling 1993 game Skidmarks. Obviously BlitzBasic was not a slow, interpreted language as one might think hearing “BASIC”. Not only is it a compiled language, it was fast enough to be billed as the next best thing to C for the Amiga, according to [Neil].

[Neil] wasn’t the only one whose dreams have been haunted by the rugose touch of the Amiga and its scquomose BlitzBasic language– you’ll find a version on GitHub called AmiBlitz3 that is maintained by [Sven] aka [honitas] to this day, complete with an improved IDE. The video includes a history lesson on the open-source AmiBlitz, and enough information to get you started.

For the vibe-coders amongst you, [Neil] has an excellent tip that you can use LLMs like ChatGPT to help you learn niche languages like this not by asking for code (which isn’t likely to give you anything useful, unless you’ve given it special training) but by requesting techniques and psudocode you can then implement to make your game. The LLM also proved a useful assistent for [Neil]’s excel-based pixel art workflow.

If you’re wondering why bother, well, why not? As [Neil] says, writing Amiga games is his version of a crossword puzzle. It may also be the only way to keep the dreams at bay. Others have taken to writing new operating systems or reproducing PCBs to keep vintage Amiga hardware alive. If some gather under the light of the full moon to chant “Ia! Ia! Commodore f’thagan”– well, perhaps we can thank them for Commodore for rising from the sunless depths of bankruptcy once again.

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Soldered RAM Upgrades Finally Available For Mac-PPC

July 30, 2025 by Tyler August 8 Comments

In the retrocomputing world, [DosDude1] is a name spoken with more than a little respect. He’s back again with a long-awaited hack for PowerPC Macintosh: soldered RAM upgrades!

[DosDude1] is no stranger to soldering his way to more storage– upgrading the SSD on an M4 Mac Mini, or doubling the VRAM on an old GPU. For a PPC Mac, though, it is not enough just to solder more RAM onto the board; if that’s all it was, we’d have been doing it 20 years ago. Once the RAM is in place, you have to have some way to make sure the computer knows the RAM is in place. For a WinTel machine, getting that information to the BIOS can be as easy as plugging in the right resistors. Continue reading “Soldered RAM Upgrades Finally Available For Mac-PPC” →

Commodore 64 On New FPGA

July 28, 2025 by Bryan Cockfield 19 Comments

When it comes to getting retro hardware running again, there are many approaches. On one hand, the easiest path could be to emulate the hardware on something modern, using nothing but software to bring it back to life. On the other, many prefer to restore the original hardware itself and make sure everything is exactly as it was when it was new. A middle way exists, though, thanks to the widespread adoption of FPGAs which allow for programmable hardware emulation and [Jo] has come up with a new implementation of the Commodore 64 by taking this path.

The project is called the VIC64-T9K and is meant as a proof-of-concept that can run the Commodore 64’s VIC-II video chip alongside a 6502 CPU on the inexpensive Tang Nano 9k FPGA. Taking inspiration from the C64_MiSTer project, another FPGA implementation of the C64 based on the DE10-Nano FPGA, it doesn’t implement everything an original Commodore system would have had, but it does provide most of the core hardware needed to run a system. The project supports HDMI video with a custom kernel, and [Jo] has used it to get a few demos running including sprite animations.

Built with a mix of Verilog and VHDL, it was designed as a learning tool for [Jo] to experiment with the retro hardware, and also brings a more affordable FPGA board to the table for Commodore enthusiasts. If you’re in the market for something with more of the original look and feel of the Commodore 64, though, this project uses the original case and keyboard while still using an FPGA recreation for the core of the computer.

Don’t Turn That Old System On, First Take It Apart

July 21, 2025 by Maya Posch 35 Comments

When you first get your hands on an old piece of equipment, regardless of whether it’s an old PC or some lab equipment, there is often the temptation to stick a power lead into it and see what the happy electrons make it do. Although often this will work out fine, there are many reasons why this is a terrible idea. As many people have found out by now, you can be met by the wonderful smell of a Rifa capacitor blowing smoke in the power supply, or by fascinatingly dangly damaged power wires, as the [Retro Hack Shack] on YouTube found recently in an old Gateway PC.

Fortunately, this video is a public service announcement and a demonstration of why you should always follow the sage advice of “Don’t turn it on, take it apart”. Inside this Gateway 2000 PC from 1999 lurked a cut audio cable, which wasn’t terribly concerning. The problem was also a Molex connector that had at some point been violently ripped off, leaving exposed wiring inside the case. The connector and the rest of the wiring were still found in the HDD.

Other wires were also damaged, making it clear that the previous owner had tried and failed to remove some connectors, including the front panel I/O wiring. Thankfully, this PC was first torn apart so that the damage could be repaired, but it shows just how easily a ‘quick power-on check’ can turn into something very unpleasant and smelly.

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2025 One-Hertz Challenge: ZX Spectrum Is Now A Z80 Frequency Counter

July 18, 2025 by Lewin Day 1 Comment

The ZX Spectrum is perhaps most fondly remembered as a home computer and a games machine. [Tito] has grabbed the faithful black plastic box and turned it into a frequency counter as an innovative entry to our 2025 One Hertz Challenge.

The code was prepared in assembly using ZASM—a Z80 online assembler. It works in quite a simple manner. The code runs for one second at a time, counting rising edges on the EAR port of the ZX Spectrum. Those edges are added up to determine the frequency in question, and the job is done. [Tito] has tested the code and found it’s capable of reading frequencies up to 20 KHz. Since it runs on a one second period, it’s thus eligible for entry by meeting the requirements of the One Hertz Challenge. Code is available on Github for the curious.

The ZX Spectrum has a clock speed of 3.5 MHz, meaning it’s not exactly the tool of choice if you’re reading faster signals. We’ve seen similar done before. In any case, this project was a great way to exercise assembly coding skills and to bust out some classic Speccy hardware—and that’s always a good time. If you’ve got your own retrocomputer hacks brewing up in the lab, don’t hesitate to let us know!

MR Browser Is The Package Manager Classic Macs Never Had

July 18, 2025 by Tyler August 2 Comments

Homebrew bills itself as the package manager MacOS never had (conveniently ignoring MacPorts) but they leave the PPC crowd criminally under-served, to say nothing of the 68k gang. Enter [that-ben] with MR Browser, a simple utility to fetch software from Macintosh Repository for computers too old to hit up the website.

If you’re not familiar with Macintosh Repository, it is what it says on the tin: a repository of vintage Macintosh software, like Macintosh Garden but apparently less accessible to vintage machines.

There are two versions available, depending on the age of your machine. For machines running System 6, the appropriately-named MR Browser sys6 will run on any 68000 Mac in only 157 KB of and MacTCP networking. (So the 128K obviously isn’t going to cut it, but a Plus from ’86 would be fine.)

The other version, called MR Browser 68K, ironically won’t run on the 68000. It needs a newer processor (68020 or newer, up-to and including PPC) and TCP/IP networking. Anything starting from the Macintosh II or newer should be game; it’s looking for System 7.x upto the final release of Mac OS 9, 9.2.2. You’ll want to give it at least 3 MB of RAM, but can squeak by on 1.6 MB if you aren’t using pictures in the chat.

Chat? Yes, perhaps uniquely for a software store, there’s a chat function. That’s not so weird when you consider that this program is meant to be a stand-alone interface for the Macintosh Repository website, which does, indeed, have a chat feature. It beats an uncaring algorithm for software recommendations, that’s for sure. Check it out in action in the demo video below.

It’s nice to see people still making utilities to keep the old machines going, even if coding on them isn’t always the easiest. If you want to go online on with vintage hardware (Macintosh or otherwise) anywhere else, you’re virtually locked-out unless you use something like FrogFind.

Thanks to [PlanetFox] for the tip. Submit your own, and you may win fabulous prizes. Not from us, of course, but anything’s possible!

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