(c) Scott M Baker, smbaker@smbaker.com

This is a Z80 Single Board Computer with the following features:

• Z80 CPU
• RC-2014 Compatible Expansion Connector
• Eight TIL311 Displays, or a 2x16 LCD/VFD Module
• 20-Key Keypad for cherry MX Blue Keyswitches
• Two serial ports (Z80 SIO/2)
• 24-bit Parallel IO Connector (Z80 PIO)
• Counter/Timer chip, optionally usable as a baud rate generator for the SIO/2
• 512 KB of banked RAM
• 512 KB of banked ROM
• Single stepper, with automated slow stepping feature
• Flexible IO address decoding using programmable logic devices

As the Z80 is only able to address 64KB or memory, the RAM and ROM are banked. Typically the excess is used as a ROM disk and RAM disk when running the RomWBW CPM distribution.

The following github repositories will be useful:

• http://www.smbaker.com/scotts-z80sbc-z80-single-board-computer, project website
• https://github.com/sbelectronics/z80sbc, Scott's Z80SBC repository containing schematics, code for the programmable logic devices, etc.
• https://github.com/sbelectronics/RomWBW, my fork of the RomWBW CP/M distribution.

The schematics are available in the schematics directory for the github repo.

• Schematic revision 0.20

The gerbers are available in the gerbers directory for the github repo.

• Gerbers revision 0.20

Zip up all of the files in this directory, upload them to JLCPCB, and you should be able to fabricate five boards for around fifty bucks. Please do read the LICENSE agreement contained in this repository for licensing requirements, and please do consider a donation to support the work that went into producing this pcboard.

Note that the board design has not been tested beyond what I did in the original video; I can't guarantee that all features work as expected. I do plan on putting some more work into this project, but I've also had several requests for boards, and making the gerbers available does sound like the easiest way to get some boards into some peoples' hands.

• z80sbc-romwbw-10122020.BIN ... This is the ROM image I found in my assembled z80sbc in October of 2020. It appears to be my fork of Wayne Warchen's ROMWBW distribution. This has been sitting on the shelf for a while, and I'm unsure the status the last time I used it.

** PLD Images

I've checked what I believe to be the correct JED files for the PLDs into the pld-galasm directory.

Sergey Kiselev's Zeta-2 Single Board computer was used as the inspiration for several parts of this designed, including the banked memory scheme.

The RomWBW CP/M distribution was essential in getting CP/M running on this board.