Can you develop on the Hydra then port to the Propeller Proto board?

TonyA

Hi,

Would it be difficult to port a prog written for the·Hydra to one of the·the Propeller Proto boards?
What would I need to do that?

Thanks.



·

Mike Green

The Protoboard is a mostly uncommitted Propeller development board. If you add the accessory kit to get a VGA display, keyboard, and mouse, you'll find that the hardware used for the keyboard and mouse is different from that used by the Hydra and the VGA display uses different pins than that on the Hydra board. None of these are problems. There's a "universal" keyboard driver in the Propeller Object Exchange library that will work with either the Hydra convention or that used on the Parallax boards. There's no equivalent yet for mouse use, but the Hydra driver uses the same calls as the standard Parallax driver and you can generally substitute one for the other. The VGA drivers are all configurable in terms of the I/O pins used. The Hydra uses a 10MHz crystal and a PLL8X multiplier while all of the Parallax devices except the Spin Stamp use a 5MHz crystal and PLL16X multiplier. Again, these are trivially configurable in your program. Have a look at FemtoBasic (in the Propeller Object Exchange) which uses a single source file for all of the Parallax devices and boards and the Hydra.

If you want a TV output from a Protoboard, you'll have to add your own resistors and a socket for the video cable. You'll have to do the same for audio if you want that ... just copy the circuitry in the Hydra manual. Similarly, if you want to use a Hydra expansion card, you'll have to add an appropriate socket to the Protoboard.

TonyA

Thank you.

So there will have to be some small changes in hardware, resistors, sockets, crystals, and drivers (if using mouse).

So, with those changes made (above) the same prog written for the Hydra could be downloaded into the Propeller chip? Would I have to add extra memory to the Propeller chip?

Mike Green

The Propeller chip has a fixed amount of memory no matter what board it's plugged into (32K main or hub RAM, 32K ROM, 8x2K cog RAM). It's the external memory that varies. The Hydra has 128Kx8 EEPROM on the board and 128Kx8 EEPROM that can be added with a memory card. Other Propeller boards usually have less, but more can be added with varying degrees of effort. The Protoboard comes with 64Kx8 of EEPROM. The Propeller chip itself only uses the first 32K of the EEPROM address space and there are very very few programs that use any space beyond that.

Please keep in mind that the Hydra is a Propeller with some specific I/O devices attached and the Propeller chip is doing most of the I/O. All of the I/O devices consist generally of a few passive components and the appropriate sockets for connection. The primary advantage of buying a Hydra is that you get a well made board at a price that you can't duplicate doing it yourself and you get the Hydra manual (with its CD) which is well written, very thorough, and with plenty of examples. Its focus is on gaming, but there's plenty on Spin and assembly and some of the video information is not available elsewhere.

TonyA

Ok, I see what you're saying. Thanks again for the help, I appreciate it.

Tony A