Scrumpel 7d Z8S180 SBC

The successor of Scrumpel 7c on one Eurocard PCB

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This SBC is a complete computer build around the Z8S180 at 18 MHz. It has 1MB RAM, 32K ROM, 8 Bit I/O Port, LCD interface for 20*4 LCD and 4 SPI devices. (The first one is for DS3234 RTC). It can run several operatingsystems made for the Z80, I.E. CP/M Fuzix.

The goal of this board is to have a complete computer-system on one PCB. It has no bus for expansions but has enough I/O to play with. The first serial port uses RTS/CTS handshaking, the second serial port doesn't. The console is on the first serial port. All components, except the CPU are trough-hole components, so easy to build. For the CPU a PLCC trough hole IC-socket is used.

A DS3234 RTC module from Dead-on is necessary for full functionality of the monitor. This module is shown in the middle of the picture below. On the right the micro SD-card module with levelconverter 5V to 3.3V is shown. On the left the serial TTL (5V) to RS232 module.

The Dead-on RTC DS3234 module is very expensive, so I designed my own module with a more commonly available battery. See picture below.

On the next picture an example how the enclosure could be with the mounted LCD

Scrumpel 7d is certified opensource hardware by the Open Source Hardware Association.


A compressed 512 MB diskimage, containing ZCPM for sd-card less or equal then 2GB. This image contains several utilities usable for Scrumpel7d on disk A:. It can be booted by the CP/M boot command in the Z180 monitor.

x-gzip - 755.01 kB - 07/12/2020 at 08:01



This is an Intel-hex file that contains the monitor for Scrumpel 7d. This version is a revision of the previous Scrumpel monitor, It support Grant Searle CP/M boot, the LCD and DS3234 RTC. It has a RTC autodetect and temperature read-out. If no RTC is detected, all RTC related functions are disabled. The DEFAULT BAUDRATE is 38400 in stead of 9600 baud.

- 19.66 kB - 06/03/2020 at 05:06



This is the Schematic diagram of Scrumpel 7d

Adobe Portable Document Format - 194.21 kB - 05/07/2020 at 04:35


These are the gerber files needed for making a Scrumpel 7d PCB, Silk screen looks better with better text lay-out

application/zip - 235.13 kB - 05/07/2020 at 04:30


  • 13 × 100 nF Ceramic capacitor
  • 1 × Z8S18033VSC CPU
  • 1 × 82C55A 8MHz Parallel port
  • 1 × Bus header female 7 pins Connector
  • 2 × ASC6C4008 55nS SRAM 512K*8

View all 35 components

View all 12 project logs

  • 1
    Soldering ceramic capacitors

    The capacitor C7 (CPU) must be placed on the solderside of he PCB and soldered on the component side, before placing the IC socket.

  • 2
    Led polarity: Power, Disk, Reset and Halt.

    The square pad on the PCB indicates the Cathode side of the LED. Long leg of LED is the Anode.

  • 3
    First start-up

    After inserting the ROM with the Scrumpel monitor you can power-up the board. But you need to connect  COM1 via FTDI or better a TTL-to-RS232 converter to a PC running a terminal program with hardware handshaking on. Otherwise the board will not run the monitor, because it's waiting for sending serial info on COM1. The default speed is set to 38400, data is 8N1 ( 8 bits, no parity, 1 stopbit). The Dead-on DS3234 RTC-module is required for saving and setting the baudrate to another speed.

    If you have connected the 20*4 LCD some info is shown with the current time and date if the RTC is also inserted. On the terminal the monitor greets you with displaying monitor greetings and, if RTC is installed the current temperature, time and date.

    ATTENTION! You must install the LC- display to be able running the monitor. The software uses hardware LCD-status check, if no LCD is installed the monitor is waiting for LCD to become ready.

View all 4 instructions

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