A smartphone-sized PCB is in a person's hand. A large blue chip package houses a 486 and the board has a SoundBlaster card and a 40 PIN Raspberry Pi Connector along one edge for attaching a Raspberry Pi Zero.

TinyLlama Is A 486 In Your Pocket

November 20, 2022 by Navarre Bartz 39 Comments

We love retrocomputing and tiny computers here at Hackaday, so it’s always nice to see projects that combine the two. [Eivind]’s TinyLlama lets you play DOS games on a board that fits in your hand.

Using the 486 SOM from the 86Duino, the TinyLlama adds an integrated Crystal Semiconductor audio chip for AdLib and SoundBlaster support. If you populate the 40 PIN Raspberry Pi connector, you can also use a Pi Zero 2 to give the system MIDI capabilities when coupled with a GY-PCM5102 I²S DAC module.

Audio has been one of the trickier things to get running on these small 486s, so its nice to see a simple, integrated solution available. [Eivind] shows the machine running DOOM (in the video below the break) and starts up Monkey Island at the end. There is a breakout board for serial and PS/2 mouse/keyboard, but he says that USB peripherals work well if you don’t want to drag your Model M out of the closet.

Looking for more projects using the 86Duino? Checkout ISA Sound Cards on 86Duino or Using an 86Duino with a Graphics Card.

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Colorful Split Keyboard Uses VGA Connections

November 19, 2022 by Kristina Panos 14 Comments

When it comes to building a split keyboard, you have a lot of options when it comes to the cable. Many will use a standard 3.5 mm TRRS cable, and others might use something more esoteric like RJ-45 to run between the halves. This only works if you’re using two controllers; if you only want one controller, you have to pass the matrix from one side to the other, which typically requires more than the four wires offered by the aforementioned choices. While rummaging around, [Joe Scotto] found a VGA cable and thought, why not use that?

This lovely Barbie-themed peripheral is a split version of an earlier board he built called the ScottoFly, which is a monoblock split with a void in the middle. As with that one, this is hand-wired using thicc brass insulated with heat-shrink, uses a solid 3D-printed plate, and a printed case. And like a madman, [Joe] coiled the cable.

Unfortunately, this proved to be problematic in the wire breakage sense, or so he thought. The real problem turned out to be that the middle row of pins on a VGA connector all act like ground, so they can’t be used to pass rows and columns. However, there were still enough viable pins to send the 4×5 matrix across. Be sure to check out the build video after the break.

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TRS-80 Gains Multiple Monitor Support, And High-Resolution Graphics

September 24, 2022 by Donald Papp 25 Comments

To call [Glen Kleinschmidt] a vintage computing enthusiast would be an understatement. Who else would add the ability to control and address multiple VGA monitors to a rack-mounted TRS-80 Model 1? Multiple 64-color 640×480 monitors might not be considered particularly amazing by today’s standards, but for 70s-era computing, it’s a different story.

Drawing this sin(x)/x ripple surface can be done in only 17 lines of BASIC.

How does a TRS-80 even manage to output anything useful to these monitors? [Glen] wrote his own low-level driver in machine code to handle that. The driver even has useful routines that are callable from within BASIC, meaning that programs written on the TRS-80 are granted powerful drawing abilities. Oh, and did we mention that the VGA graphics cards themselves were designed and made by [Glen]?

Interested in making your own? [Glen] provides all the resources you’ll need to re-create his work, including machine code drivers and demonstration BASIC programs as downloadable audio files, just as they would have been on original cassette tapes.

Watch things in action in the videos embedded below. The first draws a Land Rover, and the second plots a simple Moiré pattern star. Not bad for 70s-era hardware and 74xx logic!

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Z80 Single-Board Computer Looks Like It Could Have Been A Killer Product

August 20, 2022 by Dan Maloney 30 Comments

Most retrocomputer builds seem to focus on either restoring old machines or rebuilding them from scratch. Either way, the goal is to get as close as possible to the original machine, and while we certainly respect those builds, there are other ways to celebrate the computers of yesterday, as this Z80 single-board computer nicely demonstrates.

[Ivan Farafontov]’s SBC is sort of a “Z80 that never was” build, one that would almost have been possible back in the heyday of 8-bit computing, and would have made quite a splash if it had. Most of the peripheral chips are from Zilog and would have been found in many of the Z80 machines of the day, like the TRS-80 and ZX Spectrum. Where it goes off the old-school path is with the video section, which uses an Atmel CPLD chip and a dual-port RAM to drive a VGA monitor. It still looks the part, though, with a 256×192 pixel, 16-color display. The compact video section helps keep the overall footprint of this machine pretty small, at least by the standards of the old machines. The machine is barely larger than its custom keyboard, which is populated with mechanical switches and really nice-looking custom keycaps, and everything fits into a 3D-printed case.

The demo that starts at the 4:30 mark of the video below will be a nostalgia storm for a lot of readers, starting as it does with a version of Boulder Dash that [Ivan] wrote from scratch, along with the tile editor he used to create the sprites for the game. All the design files and code are available if you want to build your own, of course. We recently featured another Z80 that never was, but [Ivan]’s machine really makes a statement with its compact size and its capabilities.

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Have You Heard Of MCGA?

June 2, 2022 by Jenny List 21 Comments

In the world of PC graphics, the early standards followed the various video cards of the day. There was MDA, familiar through the original text-based DOS prompt, CGA, then EGA, and the non-IBM Hercules along the way. Finally in 1987 IBM produced the VGA, or Video Graphics Array standard for their PS/2 line of computers, which became the bedrock on which all subsequent PC graphics cards, even those with digital outputs, have been built. It’s interesting then to read an account from [Dave Farquhar] of the other now-forgotten video standard that made its debut with the PS/2, MCGA, or Multicolor Graphics Array. This was intended as an entry-level graphics system to compete with the more multimedia-oriented home computers of the day such as the Commodore Amiga and Atari ST.

Offering 320×200 graphics at 256 colors but only two colors at 640×480 it’s difficult to see how it could have been a viable competitor to the Amiga’s 4096-color HAM mode, but it did offer the ability to drive an RGB monitor through its VGA-like socket. The story goes that IBM intended it to provide an upgrade incentive for PS/2 customers to buy a more powerful model with VGA, but in the event a host of third-party VGA-compatible cards emerged and allowed more traditional ISA computers from third parties to retain a competitive edge and eventually sideline the PS/2 line entirely.

We called time on VGA back in 2016, and it’s fair to say that it’s disappeared from PC hardware since then even if much of its technologies still lurk within. It’s pleasing to see though that it remains a stalwart of hacked-together display interfaces, with efforts such as this 7400-based VGA card continuing to impress us.

Retro Serial Terminal Uses Modern Chips To Get CP/M Machine Talking

March 6, 2022 by Dan Maloney 26 Comments

The hobbyists of the early days of the home computer era worked wonders with the comparatively primitive chips of the day, and what couldn’t be accomplished with a Z80 or a 6502 was often relegated to complex designs based on logic chips and discrete components. One wonders what these hackers could have accomplished with the modern components we take for granted.

Perhaps it would be something like this minimal serial terminal for the current crop of homebrew retrocomputers. The board is by [Augusto Baffa] and is used in his Baffa-2 homebrew microcomputer, an RC2014-esque Z80 machine that runs CP/M. This terminal board is one of many peripheral boards that plug into the Baffa-2’s backplane, but it’s one of the few that seems to have taken the shortcut of using modern microcontrollers to get its job done. The board sports a pair of ATmega328s; one handles serial communication with the Baffa-2 backplane, while the other takes care of running the VGA interface. The card also has a PS/2 keyboard interface, and supports VT-100 ANSI escapes. The video below shows it in action with a 17″ LCD monitor in the old 4:3 aspect ratio.

We like the way this terminal card gets the job done simply and easily, and we really like the look of the Baffa-2 itself. We also spied an IMSAI 8080 and an Altair 8800 in the background of the video. We’d love to know more about those.

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Game Boy Becomes Super Game Boy With A Pair Of Pis

January 14, 2022 by Bryan Cockfield 13 Comments

For the Nintendo aficionados of the 90s, the Super Game Boy was a must-have cartridge for the Super Nintendo which allowed gamers to play Game Boy games on your TV. Not only did it allow four-color dot-matrix gaming on the big screen, but it let you play those favorite Game Boy titles without spending a fortune on AA batteries. While later handhelds like the PSP or even Nintendo Switch are able to output video directly to TVs without issue, the original Game Boy needed processing help from an SNES or, as [Andy West] shows us, it can also get that help from a modern microcontroller.

Testing the design before installing it in the NES case.

The extra processing power in this case comes from a Raspberry Pi Pico which is small enough to easily fit inside of a donor NES case and also powerful enough to handle the VGA directly. For video data input, the Pico is connected to the video pins on the Game Boy’s main board through a level shifter. The main board is also connected to a second Pico which handles the controller input from an NES controller. Some fancy conversion needed to be done at this point because although the controller layouts are very similar, they are handles by the respective consoles completely differently.

With all of the technical work largely out of the way, [Andy] was able to put the finishing touches on the build. These included making sure the power buttons, status LEDs, and reset button all functioned, and restoring the NES case complete with some custom “Game Guy” graphics to match the original design of the Game Boy. We commend the use of original Game Boy hardware in this build as well, which even made it possible for [Andy] and his wife to play a head-to-head game of Dr. Mario through a link cable with another Game Boy. If you’re looking for a simpler way of playing on original hardware without burning a hole in your wallet buying AA batteries, take a look at this Game Boy restoration which uses a Lithium battery instead.

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