# SC503 Z180 Processor Card Kit for Z50Bus

This is a Z50Bus compatible card containing a Z180 CPU, ROM, RAM, and serial ports.

- **Seller:** [Small Computer Central](https://lectronz.com/stores/s-c-central), Stowmarket, England, UK
- **Price:** $57.00 (USD, before shipping and taxes)
- **Availability:** In stock
- **Categories:** Retrocomputing, Kits
- **HS code:** 854290
- **Product page:** https://lectronz.com/products/sc503-z180-processor-card-kit-for-z50bus

## Options

**Printed circuit board colour**

- Black
- Red
- Blue
- Green
- White

**SC346 Serial to USB C adapter**

- No thanks
- 1 x Serial adapter [Add $5.50]
- 2 x Serial adapter [Add $11.00]

**SC303 Micro SD card adapter**

- No thanks
- 1 x Micro SD adapter [Add $3.00]

**SC305 Adapter cable, 6-way, 8"/200mm**

- No thanks
- 1 x Adapter cable [Add $1.00]
- 2 x Adapter cable [Add $2.00]
- 3 x Adapter cable [Add $3.00]

## Links

- [Documentation](https://smallcomputercentral.com/)

## Images

![SC503 Z180 Processor Card Kit for Z50Bus](https://lectronz-images.b-cdn.net/lectronz/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6MTg4NDYsInB1ciI6ImJsb2JfaWQifX0=--c353e8c923c37533a35ae7180ec1d96de01250f0/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJqcGciLCJyZXNpemVfdG9fbGltaXQiOls5NjAsNjQwXSwic2F2ZXIiOnsic3RyaXAiOnRydWV9fSwicHVyIjoidmFyaWF0aW9uIn19--970c165836a83091725a1a0fd4f37ce9408da1bf/SC503%20-%20Assembled%20-%203x2.jpg)
![SC503 Z180 Processor Card Kit for Z50Bus](https://lectronz-images.b-cdn.net/lectronz/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6NDA2MzYsInB1ciI6ImJsb2JfaWQifX0=--22a8184337cbbe7d4c7c8aaff7418e04e08d46b2/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJqcGciLCJyZXNpemVfdG9fbGltaXQiOls5NjAsNjQwXSwic2F2ZXIiOnsic3RyaXAiOnRydWV9fSwicHVyIjoidmFyaWF0aW9uIn19--970c165836a83091725a1a0fd4f37ce9408da1bf/USB%20serial%20Adapter%20A%20-%20w1359.jpg)
![SC503 Z180 Processor Card Kit for Z50Bus](https://lectronz-images.b-cdn.net/lectronz/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6NDA2NDAsInB1ciI6ImJsb2JfaWQifX0=--f652d9565f687714808a677505f3cb8792f07905/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJqcGciLCJyZXNpemVfdG9fbGltaXQiOls5NjAsNjQwXSwic2F2ZXIiOnsic3RyaXAiOnRydWV9fSwicHVyIjoidmFyaWF0aW9uIn19--970c165836a83091725a1a0fd4f37ce9408da1bf/SD%20Card%20Adapter%20-%20w1814%20-%20brighter.jpg)
![SC503 Z180 Processor Card Kit for Z50Bus](https://lectronz-images.b-cdn.net/lectronz/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6NDA2NDQsInB1ciI6ImJsb2JfaWQifX0=--05f3a72484ba87ec76d926e25d5f899822231fb6/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJqcGciLCJyZXNpemVfdG9fbGltaXQiOls5NjAsNjQwXSwic2F2ZXIiOnsic3RyaXAiOnRydWV9fSwicHVyIjoidmFyaWF0aW9uIn19--970c165836a83091725a1a0fd4f37ce9408da1bf/Adapter%20cable%206-way%20-%203x2.jpg)
![SC503 Z180 Processor Card Kit for Z50Bus](https://lectronz-images.b-cdn.net/lectronz/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6MTg4NTQsInB1ciI6ImJsb2JfaWQifX0=--7e03aa5514f0f44bd746334b1620b054a45d5a51/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJqcGciLCJyZXNpemVfdG9fbGltaXQiOls5NjAsNjQwXSwic2F2ZXIiOnsic3RyaXAiOnRydWV9fSwicHVyIjoidmFyaWF0aW9uIn19--970c165836a83091725a1a0fd4f37ce9408da1bf/SC503%20-%20PCB%20colours%20-%203x2.jpg)
![SC503 Z180 Processor Card Kit for Z50Bus](https://lectronz-images.b-cdn.net/lectronz/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6MTg4NTAsInB1ciI6ImJsb2JfaWQifX0=--e3d182b1729f0989275a8d42e4040a0ee8d932b4/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJqcGciLCJyZXNpemVfdG9fbGltaXQiOls5NjAsNjQwXSwic2F2ZXIiOnsic3RyaXAiOnRydWV9fSwicHVyIjoidmFyaWF0aW9uIn19--970c165836a83091725a1a0fd4f37ce9408da1bf/SC503%20-%20Plus%20accessories%20-%203x2.jpg)
![SC503 Z180 Processor Card Kit for Z50Bus](https://lectronz-images.b-cdn.net/lectronz/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6MTg4NTgsInB1ciI6ImJsb2JfaWQifX0=--104accceef70cca5881f1ccc8e908e720d28aa4f/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJqcGciLCJyZXNpemVfdG9fbGltaXQiOls5NjAsNjQwXSwic2F2ZXIiOnsic3RyaXAiOnRydWV9fSwicHVyIjoidmFyaWF0aW9uIn19--970c165836a83091725a1a0fd4f37ce9408da1bf/SC501+502+503+506%20-%20Black%202%20-%203x2.jpg)
![SC503 Z180 Processor Card Kit for Z50Bus](https://lectronz-images.b-cdn.net/lectronz/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6MTkyMzYsInB1ciI6ImJsb2JfaWQifX0=--0634ea12cbb300a58a552aa31c4a6cec298cb730/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJqcGciLCJyZXNpemVfdG9fbGltaXQiOls5NjAsNjQwXSwic2F2ZXIiOnsic3RyaXAiOnRydWV9fSwicHVyIjoidmFyaWF0aW9uIn19--970c165836a83091725a1a0fd4f37ce9408da1bf/SC503%20-%20Render%20-%20black%20-%20t%20x2.jpg)

## Description

This card is essentially a Single Board Computer (SBC) based on the Z180 CPU. It only needs a power source, a reset single, and a terminal to make a complete CP/M computer.

The card uses a Z180 CPU for good performance and RomWBW firmware for a robust implementation of CP/M with support for a wide range of hardware.

The kit comprises parts to build a Z50Bus compatible card with these main features:

- Z180 CPU running at 18.432 MHz
- 512k byte RAM
- 512k byte Flash containing RomWBW
- Two asynchronous serial ports
- SPI port primarily for SD card

Optional items:

- Micro SD card adapter 
- Serial adapter to USB
- USB cable, A to mini-B, 18"/500mm long
- Adapter cable, 6-way, 8"/200mm 

RomWBW is a robust ROM-based operating system for retro computers. It includes CP/M 2.2 and Z-System and supports a wide range of hardware, including SD cards and Compact Flash cards for storage. RomWBW has been provided free of charge by its author Wayne Warthen. Thank you, Wayne, for providing this and all the support.

The full kit includes the printed circuit board and all the components needed to make the card, as shown in the first picture. Other cards and backplanes shown in the other pictures are not included. You will require tools, solder, and cleaning materials to assemble this kit.

To use this card you will need a Z50Bus backplane, a power source, and a reset signal. The recommended modules are SC501 (or similar) backplane and SC502 power and reset card. Alternatively, you could use a backplane with a power input and a reset circuit, such as SC513. In each case, you will need to provide a D.C. power supply.

The Z180 CPU (Z8S180xx) is no longer in production and finding stock is becoming increasingly difficult. The CPU supplied in this kit is either the 20MHz or 33MHz version, and is either old or used stock. I test all of them before packing in kits. Some of the CPUs have superficial scratches. All other integrated circuits are brand new and from major retailers in the UK or USA.

### Documentation

The documentation can be found at [www.smallcomputercentral.com](https://smallcomputercentral.com/)

### Related items

- SC501 - 7-slot backplane
- SC502 - Power, reset, and status card
- SC504 - Compact Flash Interface Card for Z50Bus
- SC505 - RTC and I2C Card for Z50Bus
- SC506 - Digital I/O Card for Z50Bus
- SC138 - I2C memory card
- Components, spares, and accessories
- Pick'n'Mix printed circuit boards

### Notes

- This product is supplied as a kit of parts that require assembly.
- It is your responsibility to pay any import duty or taxes charged by your home country.
- This design is made with the permission of LiNC (designers of the Z50Bus).
- This product is designed for hobby use and is not suitable for industrial, commercial, or safety-critical applications.
- RomWBW has been provided free of charge by its author Wayne Warthen.

## Shipping policy

Products usually ship within 3 days