MOS Technology

3 Articles

Was There A Programmable PONG Chip?

August 8, 2022 by 18 Comments

Students of game console history will reach back into the 1970s for the primordial machines, tracing from the Magnavox Odyssey onwards, and thence via the Fairchild Channel F into the world of microprocessors and the chain of machines that lead us to those we enjoy today. In the early days there was a parallel evolution for a few years of dedicated video game consoles with no interchangeable cartridges or microprocessors, these took their inspiration from the legendary PONG arcade game and used dedicated non-programmable hardware in custom chips to create their video. But was there a programmable PONG chip lurking among all the others? [Old VCR] takes a look.

Many readers will be familiar with MOS Technology as the originator of the 6502 processor used in so many 8-bit home computers. But perhaps many of our attention spans will have passed over another of their products, the MOS 7600 and 7601. These were the chip company’s entry into the surprisingly congested mid-70s PONG-in-a-chip market, and the article investigates the question of whether they might in fact be mask-programmed microcontrollers masquerading as dedicated chips.

It’s a fascinating tour through the mid-70s in terms of games consoles, MOS, and through their eventual takeover, Commodore. The possibility of a mask-programmed PONG chip is explored in detail and discounted, though like [Old VCR], we’d love to see one decapped and reverse engineered. For us a stronger line of evidence comes in asking why MOS would stop at PONG if they had a mask-programmed microcontroller in their catalogue, and that our not having seen MOS microcontrollers appearing all over Commodore’s subsequent products suggests that it may be simply another dedicated PONG chip like all the others.

We’ve seen quite a few variants of this iconic game over the years, but few as impressive as one made from discrete components.

A CIA In 74HCT

September 28, 2019 by 14 Comments

If you owned a classic Commodore home computer you might not have known it at the time, but it would have contained a versatile integrated circuit called the MOS6526. This so-called CIA chip, for Complex Interface Adaptor, contained parallel and serial ports, timers, and a time-of-day counter. Like so many similar pieces of classic silicon it’s long out of production, so [Daniel Molina] decided to replicate a modern version of it on a PCB using 74HGT CMOS logic.

The result will be a stack of boards board that appear to be about the size of a 3.5″ floppy disk covered in surface-mount 74 chips, and connected to the CIA socket of the Commodore by a ribbon cable. The base board is the only one completed so far and contains the data direction registers and parallel ports, but the succeding boards will each carry one of the chip’s other functions.

It seems rather odd to use so much silicon to recreate a single chip, but the point is not of course to provide a practical CIA replacement. Instead it’s instructive, it shows us how these interfaces work as well as just how much circuitry is crammed into the chip. It’s no surprise that it’s inspired by the C74 Project, a TTL 6502 processor that we featured last year.

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Hackaday Links: August 5, 2018

August 5, 2018 by 18 Comments

Here’s something of historical interest. The daughter of Terry Holdt, project manager for the 6502, cleaned out a garage and found shelves full of MOS Technology binders, test results, notes, instructions for processes, letters to customers, and datasheets full of errata. Some of these documents have been posted on Twitter, and efforts are underway to collect, scan, upload, and preserve them. In the distance, a man in a fabulous suit is screaming, ‘donate them to the Internet Archive’.

This is a link to Defcad, the repository of 3D printable files for weapons. Under an agreement with the US Department of State, Defcad was set to go online on August 1st. This caused much handwringing in the tech journalist thoughtspace, with reporters calling to end the first amendment because they don’t like the second. Alyssa Milano chimed in. Defcad was ordered shut down by a federal judge in the western district of Washington before going live.

As you may well be aware, Printrbot ceased operations last month. It’s sad to see them go, but they made some acceptable machines and were really pushing the boundaries of what was possible with their infinite build volume prototype printer. But what about all those existing printrbots in the wild, you might ask. Well, good news for anyone who hasn’t changed their hotend over to an E3D yet: Ubis is going to be selling hotends. Get ’em while they’re hot (or not, I don’t know how this pun works).

File this one into the ‘awesome government auctions’ category. The city of Longmont, Colorado decommissioned their tornado sirens last year because they ‘self-activated’ and malfunctioned. These sirens were put up for auction, with a winning bid of $526. Someone bought the most annoying thing imaginable for just over five bills. The world of government auctions is amazing.