Salvaged Robot Arm Used For Light Painting And Pen Plotting

June 26, 2012 by Mike Szczys 5 Comments

The members of Shackspace got their hands on an antiquated robot arm. It’s a Mitsubishi Movemaster RM-101 and was probably manufactured in the mid 1980’s. There’s almost nothing out there that tells you how to use the thing, and so they set out to figure out how to control the hardware.

This is a great example of how an EPROM dump can be really useful. After further inspection the team discovered that the arm is driven by a Z80 processor whose program is stored on an EPROM. The first thing the guys did was dump the memory since the aging storage will be useless if just a few bits become degraded. This dump will be really useful for others whose chip has already given up the ghost. The data from that dump was disassembled and painstakingly pawed through to figure out what commands were being sent to the arm. This technique worked, as the team was able to re-implement the control protocol and has already used the arm for some light painting and pen plotting (seen above). After the break you can see a control demonstration.

Continue reading “Salvaged Robot Arm Used For Light Painting And Pen Plotting” →

Easy To Build Z80 Single Board Computer

August 16, 2011 by Brian Benchoff 27 Comments

[Alexis] sent in a single board computer he’s been working on. The project goal of his build was making it easily reproducible. From looking at the schematics, it’s one of the simplest fully-functional computers we’ve seen. The build runs CP/M 2.2 off of two 3.5 inch floppies. This opens up a lot of options as to what software is already available. Although it operates over a serial terminal, [Alexis] pretty much duplicated an Osborne I, only at double the speed.

[Alexis] got a little e-fame from his earlier 8088 homebrew computer built from very early 8088’s rescued from an electronics junk shop. These 8088 computers made the blog rounds by playing Still Alive with a SID chip from a Commodore 64 and a YM2151 FM synth chip.

For now, I guess we’ll have to settle for a video of [Alexis]’ Z80 computer running CP/M. Check out a video after the break of his computer running the greatest Infocom adventure, Hitchhiker’s Guide to the Galaxy.

Continue reading “Easy To Build Z80 Single Board Computer” →

Adding Persistent Memory And Ethernet To Vintage Arcade Machines

May 27, 2011 by Mike Nathan 13 Comments

z80_bus_tapper

If you are a frequent reader, you are undoubtedly familiar with hacker [Sprite_tm]. He has been working with fellow members of the TkkrLab hackerspace to get things ready for their official grand opening on May 28th, and wrote in to share a project he recently completed to kick things off.

As part of their preparations, they have been stocking the joint with all sorts of hacker-friendly goodies including plenty of tools and Club Mate, as well as a vintage ‘1943’ arcade cabinet. The game is a group favorite, though every time the power is turned off, it loses all of the hard-earned high scores. [Sprite_tm] knew he could improve on the current paper-based score register, so he pulled the machine open to see what could be done.

He used an AVR to tap into the machine’s Z80 logic board, allowing him to read and write to the entirety of the game’s RAM whenever he pleased. This enabled him to keep tabs on the high scores, restoring them to memory whenever the machine is powered back on. The addition of the AVR also allowed him to add a TCP/IP interface, which is used to send high scores to Twitter whenever someone beats the previous record.

His modular bus tap can be used in all sorts of Z80-based hardware, so if you have some vintage equipment laying around, be sure to swing by his site for a more detailed look at the build process.

Zork On The Microtouch

April 20, 2011 by Mike Szczys 10 Comments

[Rossum] just finished porting Zork over to the Microtouch. This hardware, which he originally designed, is now available for purchase through Adafruit. It’s a tiny 320×240 TFT touchscreen, driven by an AVR ATmega32u4 microcontroller. The device draws power from a lithium battery, and also boast a USB connection and a MicroSD slot.

The hack here is getting Zork to run with the limited resources available on the device. [Rossum] needed to emulate the Z80 processor, but didn’t want to use extra hardware in the way that [Sprite_TM] did when he emulated a Z80 using an AVR. Instead, this is based on a stripped-down implementation of Frotz. The final code is too big to fit on the chip along side of the bootloader. This means you’ll need to use an ISP programmer in order to flash this example to the chip. We’re pretty sure that AVRdude can program the ATmega32u4, so pretty much any ISP (including an Arduino) can be used to do the programming.

V4Z80P: The 8-bit Laptop

November 8, 2010 by James Munns 14 Comments

[Phil] over at Retroleum has cobbled together a clean, well put together laptop based entirely around a Zilog Z80 microprocessor and a pair of Spartan II FPGAs. These FPGAs allow him to reduce the number of devices on his board, and therefore cut his production cost as well as device size. He even managed to integrate a salvaged PSOne screen. The laptop comes complete with [Phil]’s own Homebrew OS as well as a great graphical vector based demo.

Sure he’s updated the project in recent years to shrink the board, speeding up the Z80, and increasing the peripheral speed and functionality, but we’re suckers here for a total package hack. Seriously though, check out the newest version of the device as well as the backlog that shows the project growing over time.

Thanks to [Steth] for the heads up.

Z80 Emulated On PIC Hardware

May 22, 2010 by Mike Szczys 18 Comments

[Jaromir Sukuba] built a very portable, low power consumption Z80 emulator using a PIC microcontroller. Looking through his build photos we love the clean and resilient construction which includes a breakout board for the PIC 32MX795F512H that interfaces with the main board via pin headers and sockets. He’s using a home-built keyboard and a 4×40 character display but there is also the option to communicate with the device over an RS232 connection. Oh, and yes it plays Zork, which seems to be the benchmark whether you are emulating a Z80 with AVR hardware, or if you built one from transistor-transistor logic.

Emulating A Z80 Computer With An AVR Chip

April 27, 2010 by Mike Szczys 13 Comments

[Sprite_tm] dusted off his assembly skills and managed to emulate a Z80 computer using an AVR ATmega88. He’s using an SD card in place of the floppy and a 128 KB DRAM chip to handle the memory for the emulated machine. An FT232 board gives him terminal access which he uses for input and display. As you can see, the hardware is much simpler than building the original would have been. He makes up for this with complicated firmware. In the end, the emulated core occupies about 2 KB of programming space after he followed the Z80 Propeller project’s idea of dividing the instructions into different modules and using a lookup table to access them.