A photo of the internal wiring.

Imagining The CPS-1: An Early 70s 4-bit Microcomputer From Canada

September 19, 2025 by 4 Comments

[Michael Gardi] wrote in to let us know about his project: CPS-1: Imagining An Early 70s 4-bit Microcomputer.

The CPS-1 was the first Canadian microprocessor-based computer. It was built by Microsystems International Ltd. (MIL) in Ottawa between 1972 and 1973 and it is unknown how many were made and in what configurations. The CPS-1 supported a 12-bit address bus and a 4-bit data bus. MIL also developed the supporting hardware including RAM. The processor was called the MIL 7114.

[Michael] worked in collaboration with [Zbigniew Stachniak] from York University Computer Museum. [Zbigniew] had developed a MIL CPS-1 Emulator and [Michael]’s job was to implement a front panel hardware interface for the emulator which runs on a Raspberry Pi. The only complication: there are no remaining CPS-1 computers, and no known photographs, so no one can say for sure what a real front panel might have looked like!

With a bit of guess work and 3D printing, as well as some inspiration from contemporaneous hardware such as the DEC PDP-11, [Michael] came up with an implementation. He used an IO extender HAT which adds 32 IO pins to the existing Pi GPIO pins that are accessible via an 3-wire I2C interface. This was enough hardware to support the 26 switches and 29 LEDs on the panel. There’s a brief demo of the custom printed switches in the video embedded below.

If you’re interested in old school 4-bit tech you might also like to check out 4-bit Single Board Computer Based On The Intel 4004 Microprocessor.

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Reviewing Deluxe Paint, 40 Years On

September 16, 2025 by 22 Comments

When Deluxe Paint came out with the original Amiga in 1985, it was the killer app for the platform. [Christopher Drum] starts his recent article on just that note, remembering the day he and his mother walked into a computer store, and walked out with a brand new Amiga… thanks entirely to Deluxe Paint. Forty years on, how well can this killer app compete?

[Christopher] isn’t putting Deluxe Paint head-to-head with modern Photoshop; they’re hardly in the same class. Not Photoshop, no, but modern applications that do what Deluxe Paint did so well: pixel art. There was no need to call it pixel art back then, no, but with the resolutions on hand, all digital art was pixel art in 1985.

Or 1989, which is when Deluxe Paint III came out– that’s the last version written by Dan Silva and coincidentally the last version [Christopher] owned, and the one he focuses in on his tests. It has held up amazingly well.

Sure, you don’t get a full 24-bit colour palette, but most pixel artists stick to limited palettes still anyway. You don’t quite get a modern UI, but presence of useful keyboard shortcuts allows a Hands-On-Keybord-And-Mouse (We’ll call it HOKAM, in honour of HOTAS in aerospace) workflow that is incredibly efficient.

About the only things [Christopher] found Deluxe Paint III lacked compared to its successors were a proper layering system, and of course the infinite undo we’ve all gotten so used to. (DPIII has an undo button, but it could only store one operation.) He also complained about cursor latency for some brushes, but we wonder if that might have had something to do with Windows and the emulation layer adding a delay. One thing Amiga was always known for back in the day was the snappy cursor movement, even when the processor was loaded.

There were just as many features he found had been forgotten in the new generation — like palatte swapping animations, or flood-filling line gradients.

It’s a small detail, but that’s a nice gradient tool.

Anyone who owned an Amgia probably has fond memories of it, but alas, in spite of Commodore’s recent resurrection, we’re not likely to see a new one soon. On the other hand, at least when it comes to pixel art, there’s apparently no need to upgrade.

via reddit.

(Thumbnail and header image by Avril Harrison, distributed by Electronic Arts with Deluxe Paint.)

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Hackaday Links: September 14, 2025

September 14, 2025 by 1 Comment

Is it finally time to cue up the Bowie? Or was the NASA presser on Wednesday announcing new findings of potential Martian biosignatures from Perseverance just another in a long line of “We are not alone” teases that turn out to be false alarms? Time will tell, but from the peer-reviewed paper released simultaneously with the news conference, it appears that biological activity is now the simplest explanation for the geochemistry observed in some rock samples analyzed by the rover last year. There’s a lot in the paper to unpack, most of which is naturally directed at planetary scientists and therefore somewhat dense reading. But the gist is that Perseverance sampled some sedimentary rocks in Jezero crater back in July of 2024 with the SHERLOC and PIXL instruments, extensive analysis of which suggests the presence of “reaction fronts” within the rock that produced iron phosphate and iron sulfide minerals in characteristic shapes, such as the ring-like formations they dubbed “leopard spots,” and the pinpoint “poppy seed” formations.

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Retro X86 With 486Tang

September 14, 2025 by 4 Comments

Tang FPGA boards are affordable, and [nand2mario] has been trying to get an x86 core running on one for a while. Looks like it finally worked out, as there is an early version of the ao486 design on a Tang FPGA board using a Gowin device. That core’s available on the MiSTer platform, which emulates games using an Altera Cyclone device.

Of course, porting something substantial between FPGA architectures is not trivial. In addition, [nand2mario] made some changes. The original core uses DDR3 memory, but for the Tang and the 486, SDRAM makes more sense. The only problem is that the Tang’s SDRAM is 16 bits wide, which would imply you need two cycles per 32-bit access. To mitigate this, the memory system runs at twice the main clock frequency. Of course, that’s kind of double data rate, but not in the same way as DDR memory.

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Hands holding a TI-99/4A.

How The TI-99/4A Home Computer Worked

September 11, 2025 by 59 Comments

Over on YouTube [The 8-Bit Guy] shows us how the TI-99/4A home computer worked.

[The 8-Bit Guy] runs us through this odd 16-bit home computer from back in the 1980s, starting with a mention of the mysterious extra “space” key on its antiquated keyboard. The port on the side is for two joysticks which share a bus, but you can find boards for compatibility with “newer” hardware, particularly the Atari-style joysticks which are easier to find. The AV port on the back is an old 5-pin DIN such as was typical from Commodore and Atari at the time (also there is a headphone port on the front). The other DB9 port on the back of the device is the port for the cassette interface.

The main cartridge interface is on the front right of the machine, and there’s a smaller expansion socket on the right hand side. The front interface is for loading software (on cartridges) and the side interface is for peripherals. The system boots to a now famous “press any key” prompt. (We know what you’re thinking: “where’s the any key!?” Thanks Homer.)

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Scott holding the demo board which has a 7-segment display and keyboard attached

4-bit Single Board Computer Based On The Intel 4004 Microprocessor

September 11, 2025 by 8 Comments

[Scott Baker] is at it again and this time he has built a 4-bit single board computer based on the Intel 4004 microprocessor.

In the board design [Scott] covers the CPU (both the Intel 4004 and 4040 are supported), and its support chips: the 4201A clock-generator, its crystal, and the 4289 Standard Memory Interface. The 4289 irons out the 4-bit interface for use with 8-bit ROMs. Included is a ATF22V10 PLD for miscellaneous logic, a 74HCT138 for chip-select, and a bunch of inverters for TTL compatibility (the 4004 itself uses 15 V logic with +5 V Vss and -10 V Vdd).

[Scott] goes on to discuss the power supply, ROM and page mapper, the serial interface, the RC2014 bus interface, RAM, and the multimodule interface. Then comes the implementation, a very tidy custom PCB populated with a bunch of integrated circuits, some passive components, a handful of LEDs, and a few I/O ports. [Scott] credits Jim Loo’s Intel 4004 SBC project as the genesis of his own build.

If you’re interested in seeing this board put to work check out the video embedded below. If you’d like to know more about the 4004 be sure to check out Supersize Your Intel 4004 By Over 10 Times, The 4004 Upgrade You’ve Been Waiting For, and Calculating Pi On The 4004 CPU, Intel’s First Microprocessor.

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