Z80 in 3 Chips

Features

• Z80
  • 12.5 MHz operation
• 512KB SRAM
• PSoC5LP
  • PSoC5 LP emulates standard Z80 peripheral chips
    • Serial port with USB
  • Memory Management Unit (MMU)
    • Controls 512KB SRAM
  • Loader moves EPROM code to SRAM
  • Controls CPU reset
• Optional MCP23017 16-bit port expander
  • I2C Addresses 0x24
• Optional Front Panel
  • I2C Addresses 0x20-0x23
• SPI interface for SDHC card

Stackup (top to bottom)

• Front Panel For 8 Bit Computers
  • 32 LEDs
  • 32 pushbutton switches
  • I2C interface
• Z80 in 3 Chips (this card)
• SD_CARD_X49 mounted on CARRIER95TO49MM
• JOYPAD

Connectors

H1 - I2C Interface

• Connects to Front Panel Card via I2C

H2 - ISP Download

• Connects to PSoC programmer

H3- Serial Port or SPI (SD Card)

H4 - I/O

J1 - USB B

• 5V card Power
• USB to Serial comm port

J2, J3 - I/O Ports

• J3 connects to JOYPAD on GPA connector

J4 - Audio Out

• DAC is the Analog function generator in the PSoC

J5 - Z80 Signals

• Useful for monitoring the CPU lines

Software

• Hardware/Software options are set in the PSoC "Hardware_Config.h" file
  • Comment out all but one choice
  • Options
    • GRANT_9_CHIP_Z80
    • GRANT_7_CHIP_Z80
    • GRANT_7_CHIP_Z80_STANDALONE
    • GRANT_FPGA_CPM
    • MULTIBOOT_CPM

Front Panel

• Card boots into Front Panel Control
• SRAM can be examined/changed in SRAM from the Front Panel
• Options to run Z80 or PSoC Monitor
  • Upper right (SW32) = Increment address, read
  • SW31 = Store data, increment address, read data
  • SW30 = Load Address, read memory
  • SW29 = TBD
  • SW28 = TBD
  • SW27 = TBD
  • SW26 = Run Monitor
  • SW25 = Run Z80

Z80_PSoC Monitor

• Press SW26 button (one in from upper left) button on Front Panel For 8 Bit Computers to run the Monitor
• PSoC Code Github repo

• Type to check the SD card

R4000

• Result:

Multiboot Multicomp (MULTIBOOT_CPM)

• CP/M Multiboot - Runs MultiComp 512KB SRAM version
• Insert "M/CPM 512KB" SD card
• Insert USB B cable
• Run PuTTY
  • 115,200 baud
• Card will power up and cycle through all the LEDs on the Front Panel
• Press SW25 (upper left button) on Front Panel For 8 Bit Computers to run Multiboot software
• PuTTY will display

Press [SPACE] to activate console

• Press SPACE
• Press H for help menu

>
  Available Commands:

  :ccxxxxiibbbbbb       Load Intel-Hex file record
  Rxxxx         Run from address xxxx
  Sddd          System boot
  Iddd          Init: Format directory
  Pddd[,xxxx]   PutSys: write system image[,loadaddress]
                (No address: re-use last loadaddress)
  Gddd[,xxxx]   GetSys: load system track

  Dxxxx[,yyyy]  Dump memory from xxxx [,to yyyy]
                D (no address) shows next block
  Cxxxx         Change/show memory at xxxx
                CR advances "," quits

  ddd is a decimal volume number,
  xxxx, yyyy is a hexadecimal address.
  Leading zeros may be omitted.
  ESC or ^C aborts.

• Type Snnn to select OS at multiboot
  • S1 - Dos+ 2.5 Copyright 1986 (c) by C.B. Falconer, CCP+ Ver. 2.2 (CP/M 2.2 compatible)
  • S2 - CP/M 2.2 (c) 1979 by Digital Research
  • S3 - CP/M Version 3.0 BIOS (2016/9/13)
    • CP/M Version 3.0 Operating System System Guide
  • S4 - MP/M II V2.1
  • S5 - Z80 BASIC Ver 4.7b, Copyright (C) 1978 by Microsoft
  • S6 - ZSDOS v1.1 (c) 1986-8 Harold F. Bower & Cameron W. Cotrill, ZCPR2 (c) 1982 by Richard Conn (CP/M 2.2 compatible)
  • S7 - ZCPR compatible system for CP/M+ (CP/M 3.0) by Simeon Cran
  • SBC-2G-512 on Retrobrewing site - Original author
  • GitHub copy of SBC-2G-512

Z80 BASIC Ver 4.7b

Reference Designs

• Z80 Reference Designs

Hackaday Page

• Hackaday Page

Assembly Sheet

• Z80 in 3 Chips Assembly Sheet