The Dual-Core, ARM-Powered Commodore 64

July 2, 2016 by 28 Comments

There is no CPU that is better understood than the 6502 and its cousins the 6510, 6507, 6509, and whatever we’re calling the CPU in the NES. With this vast amount of documentation, just about anything can be done. Want a discrete and un-discreet 6502? Sure thing. It’s the NMOS version, though. Want an emulated version. Sure. With libraries porting the 6502 to every platform ever, there’s only one place left to go: putting a 6502 in a Commodore 64. Make it dual-core, too, so we can run CP/M.

This build is based on one of [telmomoya]’s earlier builds – a soft-core 6510 running on an ARM Cortex M3. The inspiration for this build came from a 6502 emulator running on an Arduino, which got [telmomoya] wondering what would happen if he attached some external RAM, CIA or a SID. Doing this on an Arduino is hard, but there are a few 5 Volt tolerant ARM chips out there, and with a few banks of SRAM, [tel] quickly had an emulated 6502 running EhBasic.

Running an emulated 6502 on an ARM chip is nothing new. What makes this build spectacular is the adaptation to the C64 motherboard. Since [telmomoya] was already breaking out the data and address lines to go to the SRAMs, it didn’t take much extra work to simply build an adapter for the DIP40 CPU socket on a C64. A few 74-series logic chips made the interface easy, and after a bit of soldering, [telmomoya] had a Commodore 64 powered by an ARM chip.

If you’re emulating one chip, you can emulate two, and with the Commodore 64, this leads to a few interesting possibilities. The C64 had a CP/M cartridge — a cartridge that contained a Z80 CPU, sharing the data and address bus with the 6510. This cartridge allowed the ‘toy computer’ C64 to run the ‘business’ CP/M operating system (and the Z80 made the Commodore 128 much cooler).  Since [telmomoya] was already emulating a CPU, emulating a second CPU wasn’t really that hard.

It’s a phenomenal build, and great if you’ve ever wanted to speed up VisiCalc.

Adding A Second Drive To A Forgotten Commodore

December 13, 2015 by 18 Comments

Commodore would never release a laptop, or really much of anything resembling the chunky luggable portable computers of the 1980s. This doesn’t mean a ‘Commodore LCD’ wasn’t designed – it’s sitting in [Bil Herd]’s basement. Of the entire Commodore lineup, the only computer that could remotely be called ‘portable’ is the SX-64, the ‘executive’ version that came with a built-in 5″ monitor, the usual C64 circuitry, one floppy drive, and an empty hole that could obviously hold a second floppy drive. Something must be done about that missing floppy drive, and it only took thirty years for someone to do something about it.

While the conversion requires mucking around in an already tight enclosure, the parts for this conversion are readily available thanks to a few people trying to repair an SX-64, giving up, and parting the whole thing out on eBay. These parts include the 1541 controller relabeled as the ‘FDD’ board in the SX-64, and of course the floppy drive itself. With the right teardown guide, putting the new drive in this old computer isn’t that hard; just remember to cut a jumper to assign the new drive a number other than 8.

The missing floppy drive of the SX-64 is what happens when marketing is put in charge of engineering. There were a few of these dual drive Commodore luggables back in ’83, and we have the computer magazine clippings to prove it. The official story is the power supply wasn’t beefy enough to handle the second drive. This mod, though, seems to work well enough, albeit with a distinct lack of somewhere to store a few floppies.

Find yourself getting sentimental while reading about this great hardware? Keep those feelings going by listening to [Bil] recount some stories from his time at Commodore.

Ditch The IPad; Build A Commodore 64 Tablet

November 16, 2015 by 17 Comments

The classic Commodore 64 has had its share of modernizing in the OS department. From its roots starting up a basic prompt, to full high resolution GUI packages like GEOS, to today where [Jim_64] added a tablet like launcher complete with a touch screen interface.

The GUI itself takes advantage of the high resolution graphics of the C-64 that looks similar to iOS, Icons are selected via cursor keys or joystick (what? no light pen?) and launch the various functions they represent. To add to the tablet-like feel of the OS, an off the shelf 3m touch screen panel and its corresponding RS232 interface board were obtained from digikey.

With the panel securely attached to the monitor, XY data from the various finger pokes are sent via serial at a blazing 1200 bps where the program interprets the position. Using the available demo (download sideA and sideB) and off the shelf parts, this should be easy for anyone with a classic C-64 to set up in their own home and have some fun.

Join us after the break for a few demo videos!

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Golden Commodore C64 Brings The Bling To 8-Bit Computing

September 18, 2015 by 9 Comments

Sometimes, a hack is just a hack. And sometimes, a hack is nothing but a gold-plated Commodore C64.

Alright, it’s not gold-plated, it’s gilded. For the uninitiated, gilding is the process of gluing gold powder or gold leaf to an object. Gold is amazingly ductile – a tiny nugget 5mm in diameter can be hammered into a sheet of gold leaf that can cover about a half a square meter. It’s extremely thin and delicate and has to be handled very gingerly, and the gilder’s craft is therefore very meticulous. For more on gilding, see this post on signmaking with gold leaf.

[thefuturewas8bit], who runs a vintage Commodore web store, did a great job gilding a C64 case, just because. The attention to detail is fantastic – notice that even the edges of the keyboard cutouts are gilded and burnished. A nice finishing touch is swapping out the stock red power LED for a yellow one – red simply clashes too much. Lest you think there’s nothing to learn from a purely aesthetic hack, [thefuturewas8bit] shares a great tip for removing the metal badges from a plastic case – spray them with freeze-spray from the back to pop off the glue. No need to dig at them with a screwdriver and gouge or bend them. Nice trick.

Any hack can earn extra points for style, and we think that gold works well on the C64.  But if gold is a little too overstated for you, you can always try to score a colorful new injection-molded case for your vintage Commodore.

Commodore C16 Resurrection With A Raspberry Pi

August 16, 2015 by 27 Comments

[lactobacillusprime] had a non-working Commodore C16 and too many Raspberry Pi computers, so he decided to bring the C16 back to life by emulating it on the Pi. At the heart of the project is the Pi, along with a small board that converts the old style Commodore keyboards (and joysticks) to a USB port.

Once you have the keyboard as a USB port, the rest of the project is more or less mechanics and software. [lactobacillusprime] did a nice job of getting everything in the new case, along with all the I/O wires routed through the existing ports. For software, Emulation Station does the job of launching the Commodore emulation on the Pi.

Of course, there’s no reason to limit yourself to just the Commodore emulator. Emulation Station along with the right back end emulators will allow this machine to play games that no real Commodore C16 could.

Of course, we were happiest to see him boot up Commodore 64 BASIC. Perhaps we should complete all those half finished C64 BASIC projects we started back in the 1980’s. In general, we hate to see old computers gutted instead of repaired, but at least this one will continue running its software. If you are upset about seeing a machine gutted,  you can always switch over to our previous coverage of putting Commodore guts in a new box.

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CommVEx 2015: What Happens When Commodore Users Gather

July 28, 2015 by 27 Comments

I’m not getting any younger, in fact I’m getting older by the day.  This fact along with the fact that this year is the 30th anniversary of the Commodore C-128 and the original Commodore Amiga prompted me to attend this year’s CommVEx in Las Vegas lest I not be around for the next significant anniversary. For those that don’t know me, I designed the C-128 at the ripe old age of 25 back in 1984-85, though I would ask that you not hold that against me as it was a very long time ago.

Also this year Dr. Leonard Tramiel, son of Commodore’s founder Jack Tramiel, was able to swing by which was an unprecedented and unforgettable event.

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Commodore 64 Mods Make A Mobile Computer

May 22, 2015 by 16 Comments

Some Commodore C64 owners and enthusiasts keep tinkering with their precious units, adding upgrades all the time. [wpqrek]’s latest upgrade to his C64 makes it totally portable – he added DC-DC converters to allow it to run off external battery sources.

He installed two separate DC-DC converters – one for 5V and another for 9V inside the enclosure. He opted for these high-efficiency converters because he planned to use batteries to power the device and wanted to maximize the juice he was extracting. He wired up a barrel jack socket to accept a 12V input, and another XT60 socket where he could attach a LiPo battery. A common 2200mAh RC battery is enough to power his C64 for 1.5 hours. To ensure the LiPo battery doesn’t get fully discharged, he’s added a simple buzzer circuit that starts beeping at around 3.3V.

How does just adding an external battery help make it portable? Well, he’s already added a small LCD display and a couple of other mods, that we featured in an earlier post. These earlier mod’s didn’t make the unit truly portable. Adding the latest hack does. Check out the video after the break.

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