Winning The Console Wars – An In-Depth Architectural Study

November 6, 2015 by Brian Benchoff 79 Comments

From time to time, we at Hackaday like to publish a few engineering war stories – the tales of bravery and intrigue in getting a product to market, getting a product cancelled, and why one technology won out over another. Today’s war story is from the most brutal and savage conflicts of our time, the console wars.

The thing most people don’t realize about the console wars is that it was never really about the consoles at all. While the war was divided along the Genesis / Mega Drive and the Super Nintendo fronts, the battles were between games. Mortal Kombat was a bloody battle, but in the end, Sega won that one. The 3D graphics campaign was hard, and the Starfox offensive would be compared to the Desert Fox’s success at the Kasserine Pass. In either case, only Sega’s 32X and the British 7th Armoured Division entering Tunis would bring hostilities to an end.

In any event, these pitched battles are consigned to be interpreted and reinterpreted by historians evermore. I can only offer my war story of the console wars, and that means a deconstruction of the hardware.

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Breadboarding A 68000 Computer In Under A Week

November 8, 2014 by Mike Szczys 16 Comments

We’ve been lurking over at Big Mess ‘o Wires as [Steve] geared up for his 68000 computer build. One of his previous posts mentioned a working breadboard version but we figured it would be a ways off. Surprise, he’s got it working and what you see above took just 6 days of “occasional work” to get running.

The chip in use is actually a 68008 but we remember reading that he does plan to migrate to a 68000 because this one lacks the memory pins to address more than 1 MB of RAM. The trick here was just to get the thing running and he made some common choices to get there. For instance, he grounded the /DTACK in much the same way [Brian Benchoff] explained in his own 68k build.

We’re not sure if his address decoding was a time saver or not. If you study [Steve’s] original planning post you’ll learn that he’s going to use programmable logic to handle the address decoding. But above he wired up 74-series logic chips to perform these functions. On the one hand you know your Hardware Description Language isn’t the problem, but did you terminate one of those wires where you ought not?

Additional tripping points include a bouncing reset pin. Looking at that we’d tell [Steve] there’s a problem with his chip, except that this was his first thought as well. He went the extra mile by building and testing a replica of the reset system. This makes our brain spin… shouldn’t the reset be among the most reliable parts of a processor?

At any rate, great work so far. We can’t wait to see where this goes and we hope that it unfolds in a way that is as exciting as watching [Quinn Dunki’s] Veronica project take shape.

When Worlds Collide: 68008 Bootstrapped By An Arduino Uno

August 21, 2014 by Adam Fabio 23 Comments

68008-ardu

[Peter Bjornx] brings classic microprocessors and modern microcontrollers together with his Arduino bootstrapped 68008 computer. The Motorola 68008 is the 8-bit external bus version of the well-known 68000 (or 68k) microprocessor. A friend gave [Peter] one of these chips, so he built a simple computer around it.

This isn’t one of those clean retrocomputers with every connection carefully planned out and wire wrapped. [Peter’s] created a true hack – a working 68k system on a breadboard created with whatever he had on hand at the time. The real gem of this system is the ROM. [Peter] replaced an EPROM chip with an Arduino.

In the not-so-good-old-days, microprocessors (and many microcontrollers) ran from an external ROM chip. This often was a UV-erasable EPROM. Carefully compiled code was burned into the EPROM with a device programmer. If the code wasn’t perfect, the EPROM had to be pulled and placed under a UV lamp for 20 minutes or so to erase it before it was time to try again. EPROM emulators were available, but they were way too expensive for the hobbyist.

Thankfully those days are far behind us now with the advent of EEPROM and then Flash. [Peter] didn’t want to revisit the past either, so he wrote a simple Arduino sketch which allowed it to act as an EPROM emulator, including address logging via the serial port.

The design still caused [Peter] some headaches, though. His major problem was a classic 68k issue, /DTACK timing. /DTACK or Data Transfer Acknowledge is one of several bus control signals used by the 68k. When the 68k performs a read from the data bus, it waits for /DTACK before it transfers data. The Arduino was too slow to release /DTACK in this case, which caused the 68k to think every read was immediately completed. There is a much clearer explanation of the 68k bus cycles on this Big Mess O Wires page. [Peter’s] solution was simple – a D flip-flop connected to the address strobe took care of the timing issues.

It took quite a bit of tinkering, but the system eventually worked. Peter was able to run the 68008 from its reset vector into a simple loop using the Arduino. It’s only fitting that the 68k program loaded by the Arduino was an LED blinker, everyone’s favorite hardware Hello World.

Thanks [Robert!]

Hackaday 68k: So You Want A Kit?

March 27, 2014 by Brian Benchoff 67 Comments

68000

It’s yet another update to the Hackaday 68k, the wire-wrapped backplane computer that will eventually be serving up our retro site.

This is also a demo of Hackaday Projects, our new, fancy online documentation tool for all your adventures in making and tinkering. Did you know we’re having a contest on Hackaday Projects? Make something sci-fi, and you’re in the running for some really good prizes. There’s soldering stations, o-scopes, and a lot of other prizes being thrown at the winners. It’s awesome. First one to build a working Mr. Fusion wins.

In this update, I’m going to go over the beginnings of the video board, why Hammond enclosures are awesome and terrible at the same time, and some thoughts on turning this into a kit or product of some type. Click that, ‘Read more…’ link.

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Hackaday 68k: Gluing Architecture Buffer Maps

March 13, 2014 by Brian Benchoff 24 Comments

It’s time for more blatant advertising for Hackaday Projects, the best project hosting site on the Internet. Did we tell you it’s collaborative? That you and your friends can work on projects together? Want more encouragement to join? How about a contest with prizes that include oscilloscopes, FPGA dev boards, soldering and rework stations, Beaglebones and Raspberries and Spark Cores? Oh my!

Oh. We’re also developing a retrocomputer to show off the features of Hackaday Projects. This is the latest update, showing off the architecture of the entire system, the memory map, and the logic glue and buffers. The plan for this project is to have it host another awesome Hackaday site, our retro version, a small off-shoot of the main Hackaday site that’s specifically designed to be loaded by computers built before 1993. There haven’t been many retro successes in the Hackaday tip line recently, so if you manage to get a vintage computer to pull the retro site up, snap a pic and send it in.

For those of you wanting to catch up on the Hackaday 68k project, here’s the Hackaday Projects page, and here’s all the front page updates. Click that ‘Read more…’ link for the update.

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Hackaday 68k: Blinking An LED

March 5, 2014 by Brian Benchoff 47 Comments

Time for another update for the Hackaday 68k, the 16-bit retrocomputer developed on Hackaday to show off both our love for vintage hardware and our new project hosting site. There’s still invites to be had, people. Get ’em while they’re hot.

This post is going to cover exactly how complex a simple 68000 system is. The answer is, “not very.” A simple 68k system is at least as simple to design than some other homebrew systems we’ve seen around here. Yes, a 16-bit data bus means there’s more wires going everywhere, but like she said, just because it’s bigger doesn’t mean it’s harder.

There is some progress to report on the construction of the Hackaday 68k. The processor has been verified as working with a blinking LED. It’s the ‘Hello World’ of computer design, and it’s at least as complex as blinking a LED with an Arduino.

You’re gonna want to click that ‘Read more’ link.

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Hackaday 68k: Enclosure, Backplane, And Power

February 26, 2014 by Brian Benchoff 46 Comments

It’s about time for an update for Hackaday’s latest project – a modern retrocomputer based on the Motorola 68000 CPU. In this update, we’ll be taking a look at the enclosure, the backplane itself, and how we’re going to power this thing.

This is only an update to the project; you can check out the current status over on Hackaday Projects. It’s Hackaday’s new collaborative project hosting site where you (and your friends) can design, build, or document anything you have in mind. Request an invite for the alpha release of Hackaday Projects and you can give this project a skull! Seriously, this project is only the third ‘most skulled’ one on Hackaday Projects.

Now that the completely transparent pitch for Hackaday Projects is over with, we can get on to the update for the Hackaday 68k. Click that ‘Read More…’ link.

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