HYDRA Game Development Kit
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The HYDRA Game Development Kit is the latest (launched in September 2006) creation of Andre LaMothe similar to the XGameStation. Like the XGameStation, HYDRA is an open system, allowing anyone to create games for it. However, being less focused on teaching electronics and more about homebrew games, the HYDRA uses a more complex and powerful CPU - the recently released Parallax Propeller processing unit, which has eight 32 bit RISC CPUs called cogs with 32KB built in RAM and 32KB built in ROM.
The HYDRA Game Development Kit has the following specifications:
It has a Propeller CPU at 160 MIPS, (80 MHz, 20 MIPS per cog) 8 PIC-like CPU cores each with 496 32bit-words of workspace plus a shared 32kB RAM and 32kB ROM and 128kB serial EEPROM.
Its ports are: two NES Compatible Game Ports, one USB Programming port, one Serial Port or second USB port, two PS/2-compliant Ports for Mouse and Keyboard, one NTSC or PAL Video Output, or alternatively one VGA Video Output, one mono Audio output, one 20-Pin Expansion Interface connector, and one RJ-11 Peer-to-Peer Networking Port.
The Hydra comes with the large book (800+ pages) "Game programming for the propeller powered HYDRA", a CD with extensive software including demo games and a second book by LaMothe, a keyboard, a mouse, a NES keypad, USB and audio/video cables, a 128kB "memory card", an experimenter card and a power supply.
The system can be programmed as the target of a PC-hosted IDE or through locally hosted programming languages. Tiny BASIC is included with the system, and the FORTH language is also available. Of course, the Hydra can also be programmed in assembler, and in the Propeller's own built-in Spin programming language.
As the video display is generated in software, the capabilities of it depend on the software driver, but a typical PAL/NTSC driver would be able to generate a 256x192 screen resolution, and typically 80 to 96 colors maximum . The color resolution for the VGA display is hardwired to 64 colors maximum, and a typical resolution would be 800x600 depending on the available display memory. A video driver uses the main 32kB RAM which it must share with code space. With the aid of the new 512kB memory expander, video drivers can be written that extend the video generator's capabilities. To aid in the display of text the Propeller chip has a complete character font in its ROM.
Memory expansion system
A 512kB RAM expansion card, the HYDRA "XTREME 512K CARD", is available  and can be plugged into the expansion connector. It has two memory segments, a 64kB completely randomly accessible segment, and a 448kB linear accessible segment. During boot time the memory interface can be programmed to optionally auto-increment or -decrement the memory pointer for faster memory access. But the interface is based on a reprogrammable CPLD chip, so the access method can be re-programmed to suit the application; for most applications the chosen method is optimal for speed (for the 64kB segment) and utility.
The memory expansion card also has its own 128kB EEPROM on board.
- Discussion forum about the HYDRA at parallax.com
- Wiki for propeller applications, the HYDRA in particular
- More information on the HYDRA can be found at the Parallax site here and at the XGameStation site here.
- Interview of Andre LaMothe about the HYDRA at Gamasutra.
- Save and Load data in EEProm by file name.
- Image of the new HYDRA Game Development Kit