PropTerm Hardware Prototype

Saturday, 14 March 2009 06:42 administrator
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The PropTerm prototype was built using Parallax's " Propeller Proto Board" and accessory kit. The only hardware added to the board was an RS232 driver, required support capacitors, and a DB9M connector. The terminal requires four propeller chip pin connections for the host RS232 interface; TX Data, RX DATA, RTS, and CTS. The first version of the software used an external serial eeprom connected to pins A0 and A1. Once I realized that there was a 64K serial eeprom on the Propeller Proto Board I changed the software to use the 32K of the on-board eeprom not used by the Propeller chip. The four pins used for serial communications are set in the "ComHelper.spin" project file as constants.

Parallax's Propeller Proto Board

 

Proto Board Accesories Kit

The "ComHelper.spin" unit also contains the eeprom pin numbers and other eeprom related settings (page size, start offset...).

The VGA output format and pin usage are set in the "VGA_HColor_Text.spin" source file. By default the VGA is set to display 100 columns by 50 rows (800x600 @ 72hz) and uses the default Proto Board connections to VGA and PS2 keyboard.

PropTerm RS232 ProtoType

 

Last Updated on Thursday, 26 March 2009 13:30