FPGABee Version 1 - ROM Based PC85B
The first version FPGABee delivered a mostly working clone of a ROM based Microbee - similar to the PC85B model. Although the original intention was to take it further, I decided to back track and take a different approach which led to version 2 (see below).
- Runs on a Digilent Nexys3 FPGA Development Board.
- Uses OpenCore T80 for Z80 CPU
- 32K RAM, 28K ROM, 4K Video RAM/Character ROM
- Partly functional 6545 CRTC implementation - cursor, keyboard, video generation
- Connects to VGA monitor at 640x480 resolution with the Microbee output (512x256) displayed centered.
- Uses PC keyboard with natural character mapping.
- Programmable Character Graphics (PCG)
- Cassette Load (Save not implemented yet) from FAT32 formatted SD card.
- Console Mode for control over peripheral functions - read more.
Building FPGAbee Version 1
These articles describe in detail how the original version of FPGABee was built. Phase I functionality includes most of a features of a PC85B ROM based (ie: cassette) Microbee.
Note: Some of this information is now obsolete (most notably the console mode and PCU).