Flashback Project: SOCZ80 FPGA Retro Computer

Here’s a really great Papilio project that we wanted to revisit:

The SOCZ80 Retro Computer! Here is some more info:

I built a small FPGA microcomputer for the Papilio Pro board. I’ve ported a few operating systems to run on it. These 8-bit machines have very minimal features but (somewhat unexpectedly) I found they can run a multi-user, multi-tasking UNIX operating system.

The hardware specification is:

• Z80 compatible T80 CPU core at 128MHz
• 4KB paged MMU (64KB virtual, 64MB physical address space)
• 8MB SDRAM (at 128MHz), with 16KB direct-mapped cache
• 4KB ROM with monitor program
• 4KB SRAM
• UART with deep receive FIFO
• Optional second UART with FIFO and hardware flow control
• 1MHz Timer
• SPI master connected to SPI flash ROM
• SPI master connected to optional SD card socket
• GPIO

I’ve ported the following operating systems:

• CP/M-2.2
• MP/M-II
• UZI

Project Link