Apple ][ Disk Emulation

March 29, 2015 by Brian Benchoff 18 Comments

A while ago, [Steve] over at Big Mess ‘O Wires created a device that would emulate old Macintosh disk drives, storing all the data on an SD card. No, it’s not SCSI; the early Apples had a DB-19 connector for connecting 400 and 800kB disk drives. It’s a great piece of hardware for bootstrapping that old Mac you might have sitting around. Apple ][s, IIs, and //s use an extremely similar connector for their disk drives. A few rumors on some forums led [Steve] to experiment with some ancient bromide-stained boxes, and the results are interesting to say the least.

After pulling out an old //e and IIgs from storage, [Steve] found his Macintosh Floppy Emulator didn’t work with the Apples. This was due to the way Apples could daisy chain their disk drives. There’s an extra enable signal on the connector that either brings Drive 1 or Drive 2 into the circuit. Macs don’t care about this signal, but Apples do. Luckily the 800kB drives for the IIgs have an extra board that handles this daisy chain and drive eject circuitry.

After removing this extra board from a IIgs drive and connecting it to the Floppy Emu, everything worked beautifully. With schematics and a working circuit in hand, it’s now a piece of cake to build an adapter board for using the Macintosh Floppy Emu with Apples, or to build that circuit into a future revision of the Floppy Emulator.

Considering how much trouble [Steve] had bootstrapping these Apples without an SD card to Floppy drive emulator, we’re thinking this is great. The current way of making an Apple II useful is ADTPro, a program that uses audio to communicate with Apples over the cassette port. In case you haven’t noticed, microphone and headphone ports on laptops are inexplicably disappearing, making a hardware device like a SD card floppy emulator the best way to bring disk images to 30-year-old hardware.

An FPGA Based 6502 Computer

August 16, 2014 by Eric Evenchick 20 Comments

A diagram of the CHOCHI Board

It’s no secret that people love the 6502 processor. This historic processor powered some of our favorite devices, including the Apple II, the Commodore 64, and the NES. If you want to play with the 6502, but don’t want to bother with obtaining legacy chips, the CHOCHI board is for you.

While many people have built modern homebrew 6502 computers, the CHOCHI will be much easier for those looking to play with the architecture. It’s based on a Xilinx XC3S50 FPGA which comes preconfigured as a 6502 processor.

After powering on the board, you can load a variety of provided binaries onto it. This collection includes a BASIC interpreter and a Forth interpreter. Of course, you’re free to write your own applications in 6502 assembly, or compile C code for the device using the cc65 compiler.

If you get bored with the 6502 core, you can always grab Xilinx’s ISE WebPACK for free and use the board as a generic FPGA development tool. It comes with 128K of SRAM and 31 I/O pins. Not bad for a $30 board.

Apple ][ Graphics As Your Screensaver Or Second Screen

July 18, 2014 by Mike Szczys 16 Comments

Hipsters rejoice, you can actually make those high-tech IPS panels look like crap. Really nostalgic crap. [Kaveen Rodrigo] wrote in to show how he displays weather data as his Apple ][ emulated screensaver.

He’s building on the Apple2 package that is part of the xscreensaver available on Linux systems. The program has an option flag that allows you to run another program inside of it. This can be just about anything including using it as your terminal emulator. [Adrian] recently sent us the screenshot shown here for our retro edition. He is running bash and loaded up freenet just to enjoy what it used to be like in the good old days.

In this case, [Kaveen] is using Python to pull in, parse, and print out a Yahoo weather json packet. Since it’s just a program that is called when the screensaver is launched, you can use it as such or just launch it manually and fill your second monitor whenever not in use.

We gave it a whirl, altering his code to take a tuple of zip codes. Every hour it will pull down the data and redraw the screen. But we’ve put enough in there that you’ll be able to replace it with your own data in a matter of minutes. If you do, post a screenshot and what you’re using it for in the comments.

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VCF East: The Swyft Card

April 6, 2014 by Brian Benchoff 31 Comments

Ninety five percent of the population will say Apple computers is the brainchild of [Steve Jobs]. The other five percent will be right, but what nearly no one knows is that the Macintosh project was originally conceived by [Jef Raskin]. He holds the honor of turning the Mac into an, ‘information appliance’ and being one of the first people to seriously consider how millions of people would interact with computers.

The Mac wasn’t [Jef]’s first project at Apple, though. Before the Mac project he was working on something called Swyft – an easy to use command line system that was first implemented as a firmware card for the Apple IIe. [Mike Willegal] was kind enough to bring one of these Swyft cards to the Vintage Computer Fest this weekend, and did a demo of it for us.

The basic idea behind the Swyft card was to have an integrated word processor, calculator, and access to Applesoft Basic. Holding down a ‘leap’ key – in the case of the Apple IIe add-on, the open apple key – allowed the user to search for text and perform operations on any result. It’s odd, but it just makes sense in some strange way.

[Mike] is doing a build class at the VCF today where anyone attending can build their own Swyft card. He also has instructions for building your own, should you want to experiment with one of the ‘could have beens’ of user interface design.

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Hackaday Links: January 26, 2014

January 26, 2014 by Mike Szczys 7 Comments

The automotive industry is rolling more and more tech into their offerings. This is great for us because replacement or salvaged parts are great for projects. Here’s one component to look for. [MikesElectricStuff] tears apart the thermal imaging camera form an Audi. [via Hacked Gadgets]

Give your valentine an analog love note on the big day. [Tom’s] LED heart chaser design does it without any coding. It’s a 555 timer with CD4017 decade counter. The nice thing about the setup is a trimpot adjusts the chaser speed.

[Jan] is overclocking his Arduino to 32 MHz. For us that’s kind of an “eh” sort of thing. But his statement that you need to use a clock generator because the chip won’t work with an oscillator at that frequency raised an eyebrow. We saw an AVR chip running from a 32MHz crystal oscillator in the RetroWiz project from yesterday. So do we have it wrong or does [Jan]? Share your opinion in the comments.

Download a copy of the Apple II DOS source code… legally. Yay for releasing old code into the wild! The Computer History Museum has the DOS source code and a bunch of interesting history about it. [via Dangerous Prototypes]

While we were prowling around DP for the last link we came across [Ian’s] post on a new version of Bus Pirate cables. We’ve got the old rainbow cables which are pretty convenient. But if you’ve used them you’ll agree, hunting for the correct color for each connection isn’t anywhere near a fool-proof method. The new cable uses shrink tube printed with probe labels. They sound like a huge pain to manufacture. But this makes connections a lot easier. In our experience, when it doesn’t work its always a hardware problem! Hopefully this will mean fewer botched connections.

Make your tiny LiPo cells last longer. Not capacity wise, but physically. The delicate connections to the monitor PCB break easily, and the plug is really hard to connect and disconnect. [Sean] shows how he uses electrical tape for strain relief, and a bit of filing to loosen up the connector.

KerbalEdu: Kerbal Space Program for education. That’s right, you can play Kerbal as part of school now. Some may shake their heads at this, but school should be fun. And done right, we think gaming is a perfect way to educate. These initiatives must be the precursor to A Young Lady’s Illustrated Primer method of education. Right?

Apple And Raspberry Pis

December 26, 2013 by Brian Benchoff 22 Comments

A2Pi

Deep in the bowels of the Internet there are some crazy people who have a wish list for what the next Apple II should look like. The capabilities of this dream machine of 80s retrocomputing is generally said to be something with a 32-bit CPU, a UNIX OS, modern graphics, and networking. This sounds a lot like a Raspberry Pi, so [Dave] built an Apple II to Raspberry Pi adapter card.

Having a Pi talk to an Apple II over a serial connection doesn’t really give either machine the full capabilities of the other. To fix this issue, [Dave] wrote two pieces of software. The first is a UNIX daemon that listens to the Apple II on a serial port connection, handling the Apple II keyboard connection. The second piece of software is a ProDOS disk image file running on the Apple II. With these two pieces of software, [Dave] can run the Apple on the Raspi, or run the Raspi on the Apple, sending files and data back and forth with no problem.

Aside from providing a strange and awesome Apple II to UNIX interface, the Apple II Pi also has a lot of advantages that might not be readily apparent. An Apple II compact flash adapter can be used as an internal hard drive for these pieces of classic apple hardware, and the Uthernet Ethernet card for the AII brings networking. Both of these devices are absurdly expensive compared to the component cost of the Apple II Pi, and what they bring to the table can be easily copied by the Apple II Pi.

The Apple II Pi is just a simple double-sided board with a few resistors, a cap, header, a 7404 inverter, and a communications chip that’s $5 for quantity one. If you already have a Raspi hanging around your workbench and want to soup up an Apple II with some crazy hardware capabilities, you really can’t do better than getting one of these Apple II Pi boards. Now if we could only find the board files…

Video of the Apple II Pi below, showing off all the awesome capabilities of a Pi-powered Apple. Thanks [Itay] for sending this one in.

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The Apple IIe Becomes A Lisp Machine

October 20, 2013 by Brian Benchoff 36 Comments

Way back in the late 1970s and early 1980s, a few very awesome people around MIT were working on Lisp machines. These computers were designed specifically to run Lisp as their main programming language. Around the same time, a few [Steves] in California were working on the Apple II, which would soon become one of the most popular computers of all time. The Apple II ran BASIC as its main programming language, fine for the time, but surely not as elegant as Lisp. It took more than 30 years, but [Alex] and [Martin] figured out a way to turn the lowly Apple IIe into a Lisp machine.

Developing Lisp for the Apple IIe was surprisingly easy for these guys – they simply wrote a Lisp interpreter in C and used a 6502 compiler to generate some machine code. The main problem of porting Lisp to an Apple II was simply getting the code onto the Apple. We’re assuming this would have been easier had the same project been attempted in the 80s.

To get their interpreter onto the Apple, they used the very awesome ADTPro library that allows data to be loaded onto an Apple II via the cassette port and a modern computer’s microphone and speaker jack. After a solid minute of loading analog data onto this digital dinosaur, [Alex] and [Martin] had a Lisp interpreter running on ancient yet elegant hardware.

The source for the 6502 Lisp interpreter can be found on the GitHub along with all the necessary tools to load it via a modern computer. That’ll give you all the ancient lambdas and parens you could ever want. One warning, though: backspace doesn’t exactly work, so be prepared for a lot of frustration.

You can check out the demo video below.

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