This board features printing in ENIG.

The project is an upgraded / evolved TRS-80 Model I main board replacement. It was designed to provide a reliable, compact, and modern replacement, removing some limitations of the original 1970's product, while still remaining faithful to the original technology (i.e. no emulation)

Features at a Glance

• CPU double speed (3.56 Mhz), configurable by jumper or external switch.
• System ROM's have been replaced with standard 32 pin EPROM (27xxx) or EEPROM (28xxx).
• Larger ROM's allow multiple paged ROM images selectable by Jumper.
• ROM can be configured to occupy the empty memory region (12-14kb) above the main ROM.
• A full 48Kb of RAM is provided by a single modern SRAM chip.
• Video character generation is provided by standard 32 pin 27xxx EPROM's or 28xxx EEPROM's
• Video character generator provides full 6x12 pixel matrix (Gendon3 compatible) descenders.
• Multiple character sets can be defined, the character set chosen is by dip switches.
• The Video sync has been upgraded with improved stability, and 50Hz PAL support.
• Video Output is via traditional DIN, or optional RCA socket.
• An internal 40 pin header is provided for plug in expansion cards
• A FreHD board has been developed primarily for internal expansion.
• Power and Reset switches can be either traditional or modern components.
• The cassette input has minor improvements in the A/D design.
• All internal power regulation circuitry has been removed, now externally provided.
• Overall modernisation, including full GND planes, decoupling capacitors, silkscreen.
• A prototyping area is provided on the board, for user provided enhancements.