The design is built around a ZiLOG eZ80L92 Z80-compatible microprocessor. System memory is provided by a 128KiB SRAM. Disk storage is provided by a microSD card connected to the L92's SPI bus. A USB to Dual UART bridge provides connectivity for a serial console. A ZiLOG Z8 Encore! XP microcontroller bootstraps the system using the L92's ZDI debug interface. An LDO regulator powers the system from the USB bus. Below is a block diagram of the system.
The default disk manager configuration emulates four 8" single density floppy disks and two 4MB hard disk. Disk images on the microSD card are associated with a drive using the mount command, e.g. mount mbasic.dsk b.
Use of a microSD card and the FAT file system makes loading disk images as simple as copying files. The choice of disk geometries matches many of the disk images provided for the z80pack development system.
This project would not have many of its features without projects like FatFs, z80pack and others.
Here's a short video of the board in action.
Software Development Tools
- ASxxxx Cross Assemblers
- ZDS II – eZ80Acclaim! version 5.3.0
- ZDS II – Z8 Encore! Version 5.2.2
The Zilog Developer Studio packages now appear to be gratis.