MEK6802D3 Microcomputer Unit - Manual
The information in this document has been carefully checked and is believed to be entirely reliable. However, no responsibility is assumed for inaccuracies. Furthermore, such information does not convey to the purchaser of this product described any license under the patent rights of Motorola, Inc., or others.
Introduction
The MEK6802D3 is a single board computer system that empìoys the MC6802 microcomputer chip. In addition to the MC6802, the system contains a 2K operating system in firmware, Random Access Memory (RAM) data storage, keyboard/display for input and display of data, and an I/O bus interface for expansion.
The MEK6802D3 computer system was developed as an educational tool for people interested in learning about microcomputers. This low cost single board computer system contains sufficient hardware and firmware for beginners to write, debug, and execute programs in machine language containing up to 256 bytes. Provisions are made for extensive system expansion using the system bus. There is a family of bus compatible support boards that permit easy expansion of the D3 card into a highly sophisticated computer.
This manual provides a general operating description of both the hardware and firmware, and the features of the MEK6802D3 as a stand-alone computer. The details of how to expand the MEK6802D3 are separated from the main material to minimize confusion.
Table of Contents
- Chapter 1 - General description and operation
- 1.0 Generaì Description
- 1.1 Address Space (stand-alone computer)
- 1.2 Firmware Features
- 1.3 Preparation For Use
- 1.4 Start Up Procedure
- 1.5 Operating Procedure
- Chapter 2 - Hardware Description
- 2.0 Central Processing Unit (CPU)
- 2.1 Memory and Address Logic
- 2.2 I/O
- Chapter 3 - Expansion Description
- 3.0 Introduction
- 3.1 System Configurations
- 3.2 Expanded Memory Address Space
- 3.2.1 Expansion Firmware Features
- 3.3 I/0 Expansion Bus
- Chapter 4 - Software Description (D3BUB Monitor)
- 4.0 General Description
- 4.1 Restart/Initiaï ization Routine
- 4.2 Display/Comnand Execution Routine
- 4.3 Keypad/Decode Routine
- 4.4 Function Decode Routine
- 4.5 Interrupt Handling Routines
- 4.5.1 Maskable Interrupt Request
- 4.5.2 NonMaskable Interrupt
- 4.5.3 Software Interrupt
- 4.6 User Callable Subroutines
- 4.6.1 ROLENT
- 4.6.2 DYSCOD
- 4.6.3 ADDXA
- 4.6.4 EFPI
- 4.6.5 EXTST
- 4.6.6 CLRD
- 4.6.7 DLY, DYL1, DLY25
- 4. 6.8 GET
- 4.6.9 ADDR
- 4.6.10 DISNMI
- 4.6.11 ENNMI
- 4.6.12 GETIT
- 4.6.13 IRQ
- 4.6.14 LOAD
- 4.6.15 S300LD
- 4.6.16 S1200P
- 4.6.17 S300P
- Appendix 1: D3BUG 1.0 Assembly Listing
- Appendix 2: Parts List
- Appendix 3: System Schematic
- Appendix 4: Data Sheets
- Appendix 5: Number Systems and 6800 Addressing Modes