If you are interested in how a computer works at the hardware grass-roots level, past all the hardware and software abstractions intended to make them easier to use, you can sometimes find yourself frustrated in your investigations. Desktop and laptop computers are black boxes both physically and figuratively, and microcontrollers have retreated into their packages behind all the built-in peripherals that make them into systems-on-chips.
Continue reading “The BASIC Issue With Retro Computers”
As hackers and makers we are surrounded by accessible computing in an astonishing diversity. From tiny microcontrollers to multi-processor powerhouses, they have become the universal tool of our art. If you consider their architecture though you come to a surprising realisation. It is rare these days to interface directly to a microprocessor bus. Microcontrollers and systems-on-chip have all the functions that were once separate peripherals integrated into their packages, and though larger machines such as your laptop or server have their processor bus exposed you will never touch them as they head into your motherboard’s chipset.
A few decades ago this was definitely not the case. A typical 8-bit microprocessor of the 1970s had an 8-bit data bus, a 16-bit address bus, and a couple of request lines to indicate whether it wanted to talk to memory or an I/O port. Every peripheral you connected to it had to have some logic to decode its address and select it when you wanted to use it, and all shared the processor’s bus. This was how those of us whose first computers were the 8-bit machines of the late 1970s and early 1980s learned the craft of computer hardware, and in a world of Arduino and Raspberry Pi this now seems a lost art.
The subject of today’s review then provides a rare opportunity for the curious hardware hacker to get to grips with a traditional microprocessor bus. The RC2014 is a modular 8-bit computer in which daughter cards containing RAM, ROM, serial interface, clock, and Z80 processor are ranged on a backplane board, allowing complete understanding of and access to the workings of each part of the system. It comes with a ROM BASIC, and interfaces to a host computer through a serial port. There is also an ever-expanding range of further peripheral cards, including ones for digital I/O, LED matrixes, blinkenlights, a Raspberry Pi Zero for use as a VDU, and a small keyboard.
Continue reading “Review: The RC2014 Z80 Computer”
[gilmour509] posted a thorough gallery of a new custom-built computer and case made to look like a 1995 IBM Aptiva. While the whole build is impressive, the most clever part involves a 3 1/2″ floppy disk that hides an SD card and works like a regular USB flash drive when inserted into the floppy drive.
He makes use of the fact that floppy disk edge card connectors have the same spacing as SD cards. Add in a hacked USB card reader, some careful cutting and assembly, and [gilmour509] has a very convincing floppy drive with gigabytes of space.
The best part is that with everything put together, the floppy disks and floppy drive look completely unmodified. He even made the file explorer icon show a floppy drive.
The faux-Aptiva gallery includes the full build, but skip to about 2/3 down to see the floppy SD card section.
Continue reading “Floppy Drive Hides SD Card Reader”
Some readers out there probably have nostalgic feelings for their first 386 based PC, the beeps and hisses of the modem, and the classic sound of a floppy drive’s stepper motor. Perhaps that turbo button that we could never quite figure out.
If you want the power of a 386 processor today, you’re in luck: [Pierre Surply] has developed a modern development board for the 80386SX CPU. This board is based on a 386 processor that comes in a LQFP package for “easy” soldering, and an Altera Cyclone IV FPGA.
To allow the CPU to run, the FPGA emulates the chipset you would usually find on a PC motherboard. The FPGA acts as both a bus controller and a memory controller for the CPU. On the board, there’s an SRAM chip and internal memory on the FPGA, which can be accessed through the 386’s bus access protocol.
The FPGA also provides debugging features. A supervisor application running on the FPGA gives debugging functionality via a FTDI USB to UART chip. This lets you control operation of the CPU from a PC for debugging purposes. The FPGA’s memory can be programmed through a JTAG interface.
The project is very well documented, and is a great read if you’re wondering how your old 386 actually worked. It can even be hand soldered, so the adventurous can grab the design files and give it a go. The francophones reading can also watch the talk in the video below.
Continue reading “A Modern 386 Development Board”
By this point we are all familiar with [Quinn Dunki] and her awesome engineering and retro hacking. [Quinn] aims her latest blog post at the Apple IIc Plus and its tone deaf bleeping beep. You can hear it for yourself in her beep comparison video after the break.
[Quinn] gets straight into the source code as expected and works through a logical process that she explains quite nicely while looking for the origin of the problem. There are some interesting and hard to follow moves in the source as control jumps around the ROM(s) all in the name of minimizing RAM. In proper form [Quinn] uses the ROM bank switching ability to her advantage as she see’s [the Woz’s] efficiency and raises him some fancy footwork of her own along with a beep that doesn’t make our skin crawl.
Continue reading “[Quinn] Uses “Forsooth” To Win The Internet! –Also Fixes Apple IIc+ Beep”
All good things, and apparently our coverage of Maker Faire, must come to an end. Here’s a few more things we saw in New York this last weekend that piqued our interest:
A 10x scale Arduino
[Robert Fitzsimons] of Part Fusion Electronics made a gigantic Arduino. It wasn’t quite functional, but [Robert] did manage to make a few 10:1 scale LEDs (with built-in circuit protection), 1 inch pitch headers, and a few other miscellaneous components out of foam and paint.
Since he’s from Dublin, Ireland, [Robert] didn’t want to take this giant board home with him. He graciously gave it to me in the hopes of turning it in to a proper working Arduino. I’ll do my best, [Robert].
There are hundreds of Lisas buried in a landfill in Utah.
Tekserve, an indie Apple store located in the heart of Manhattan, really knows how to put on a good show. For the entirety of their stay at Maker Faire, they had people showing off one of the first digital cameras, Apple Newtons, and an awesome collection of vintage Macs. No, your eyes do not deceive you; that’s a real Lisa there in the bunch.
Sadly, they didn’t have the boot disk to turn any of these on. Pity.
Yes, there were celebrities at Maker Faire
Well, celebrities to the Hackaday crowd, at least. [Ben Heck] showed off the electronic automatic sunglasses he built. It’s a pair of lensless glasses, a servo, light detector, and a pair of clip-on sunglasses. When [Ben] is out in daylight, the sunglasses swivel down. Inside, the amount of light received by the detector decreases and the shades rotate up.
Continue reading “Wrapping up Maker Faire with [Ben Heck], giant Arduinos, and an Apple Lisa”
Part of the fun with old computers is playing some old school games, and while you could play them with a keyboard it is much more fun with a joystick. You can get old joysticks all day long on auction sites, but you have to watch out. Some are digital, which wont work for many games on many systems. Some were cheap to begin with and probably worn out, and many are flight sticks … ever play pac-man with a giant flight stick?
What I really wanted was a game pad like device for my 1986 Apple //c , using one of the modern thumbstick analog controllers. Using a thumbstick out of an old XBOX(1) controller, some generic parts from Radio Shack, and a little bit of effort , I ended up with exactly what I wanted.
Join us after the break and I will show you how to get there!
Continue reading “Analog Joypad for your Retro PC”