dos

44 Articles

Repairing A Mill That Cost As Much As A Car

August 8, 2013 by 45 Comments

miters

Years ago, someone at the bio-instrumentation lab at MIT needed to change a CMOS battery in the controller for a three axis mill. This reset the machine’s BIOS and was widely regarded as a bad move. The mill sat in the lab for a few years before  Prof. [Ian Hunter] donated it to MITERS – the student shop at MIT. And so the task of repairing a machine that cost as much as a car fell upon a plucky group of students.

The machine – a  Dyna-Myte 1007 has a 10″x7″x10″ work area, pneumatic tool changers and carousel, and the working for a fourth axis. It is. however, driven by an ancient Pentium computer running DOS with all the fun of ISA slots and IRQs that entails.

The MITERS began their repair by digging around in the software configuration, finding the axis drive is controlled via IRQ 3, which was currently occupied by COM 2. Changing that in the BIOS let the computer control the axes and, with a few solenoids and an air compressor, the tool carousel also worked.

With a bit of digging around, the MITERS also got the spindle working, giving them a very awesome and very expensive CNC milling machine for free. Even though the computer could be replaced with a $35 Raspberry Pi, we really have to admire the MITERS for fixing what they already had; it’s a cheaper and much, much faster way to get their new toy up and running.

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Raspberry Pi: The Perfect Machine For Old DOS Games

March 26, 2013 by 62 Comments

DOS

There’s a treasure trove of excellent yet ancient games made for DOS that are nearly unplayable on modern computers. Awesome games like the Lucasarts SCUMM adventures, the original Civilization and SimCity, Starflight, the King’s Quest series and even Leisure Suit Larry aren’t played much today because of the near impossibilities of getting them to run on modern hardware or setting up an emulator with proper sound.

[Patrick] has been doing his best to help out classic gamers with an x86 emulator for the Raspberry Pi. It’s designed to be a very capable DOS box with 20 MB of extended memory, a 640×480 display with 256 colors, an ~20MHz 486 emulated CPU, and a Soundblaster 2.0 sound card.

There’s still a lot of work to be done, but outside of finding a 20-year-old computer, emulation on a Raspberry Pi it probably the most authentic DOS gaming experience you’ll get.

BASH Games

February 5, 2013 by 18 Comments

Get serious about your shell scripting skills and maybe you can pull this one off. It’s a game of snake played in a BASH shell. It seems like a coding nightmare, but the final product turns out to be organized well enough for us to understand and took less than 250 lines of code.

[Martin Bruchanov] started on the project after pining for an old DOS game called Housenka. It’s another version of the classic Snake game which we’ve coded ourselves and seen in several projects including this head-to-head version using musical recorders as controllers. When using a terminal emulator capable of ANSI sequences the game is displayed in color using extended characters.

We give [Martin] bonus points for the way he wrote about his project. It describes the mechanics most would be interested in, like how the user input is captured and what drives the update function and food generation. The rest of the details can be gleaned by reading through the code itself.

Hacking A Parallel Port Flash Memory Programmer

July 14, 2012 by 12 Comments

[Pulko Mandy] doesn’t use his flash ROM programmer very often, but he does use it. When he tried to get support for a new chip and the manufacturer suggested he just buy a newer version he decided to hack the programmer and it’s software instead.

This device connects to the parallel port and was intended for use with MS-DOS systems (no wonder there’s no longer support from the company). The board uses logic chips to add read and write function. So the first step was to analyze how they connect together and come up with a set of commands. While at it he also made some changes to the board to bring the voltage more in spec and ensure the logic levels on the parallel port met the correct voltages.

His plan was to use the board with a Linux system so the parallel port interface can stay. He used what he learned from the hardware inspection to write his own interface in C++. It works with a chip he was able to use under the MS-DOS software, but he hasn’t gotten it to work with the chip that sparked this adventure. If you’re familiar with how the AT29C040A works please consider lending a hand.

XT IDE Controller

July 31, 2010 by 35 Comments

[Geordy] wanted to use some IDE devices but he didn’t have an interface card for his XT system, which can’t handle 16-bit  IDE. He looked around for 8-bit ISA controllers but they were hard to find and quite expensive. Lucky for him there’s an open source project that makes a solution to this problem. The XTIDE project brought together a group of vintage computing enthusiasts to design this ISA card. [Geordy] was even able to order a professional PCB from one of the forum members. He ordered the parts an soldered it together, costing about $30 total. He had a friend help him burn the code to the EEPROM but that’s easy enough to do with an Arduino, Bus Pirate, or one of several other methods. Now his grand plans at installing DOS 6.22 have been realized.

DIY Picture Frame Better Than Store Bought

July 30, 2010 by 22 Comments

[Daniel’s] homemade digital picture frame looks great, it’s well-built, and it has a nice set of features. It’s not made from a broken laptop and he didn’t build it around a microcontroller. Instead, he saved a 19″ LCD monitor with a burnt out back light caused by the extremely common blown capacitor problem. Twenty dollars on eBay landed him a small industrial single board computer to drive the system.

The software end of things is a curious conglomeration but considering the hardware constraints [Daniel] made some great choices. He’s using MS-DOS along with LxPic for slide shows and Mplayer for video. The rest of the software gets him up on the home network and enables IR remote control via LIRC. All o this makes for a beautiful product (video after the break includes some Doom footage) and the package is pulling just 40W when in use.

Slowloris HTTP Denial Of Service

June 17, 2009 by 40 Comments

[RSnake] has developed a denial of service technique that can take down servers more effectively. Traditionally, performing a denial of service attack entailed sending thousands of requests to a server, these requests needlessly tie up resources until the server fails. This repetitive attack requires the requests to happen in quick succession, and is usually a distributed effort. However, [RSnake]’s new technique has a client open several HTTP sessions and keeps them open for as long as possible. Most servers are configured to handle only a set number of connections; the infinite sessions prevent legitimate requests from being handled, shutting down the site. This vulnerability is present on webservers that use threading, such as Apache.

A positive side effect of the hack is that the server does not crash, only the HTTP server is affected. His example perl implementation, slowloris, is able to take down an average website using only one computer. Once the attack stops, the website will come back online immediately.

Update: Reader [Motoma] sent in a python implementation of slowloris called pyloris

[photo: cutebreak]