Heathkit ET-3400 Microprocessor Trainer

This repository contains resources for the Heathkit ET-3400 Microprocessor Training System. We did not generate these resources unless otherwise noted. These resources are provided to help students independantly gain a deeper understanding of embedded systems. While the 6800 processor family is long obsolete, the architecture of these processors lives on in many embedded systems. Understanding these "simple" processors of the past helps gain a deeper appreciation of modern systems.

Repository also includes examples of Kansas City Standard (KCS) encoding and decoding of files as audio that can be used with the Heathkit ET-3400 Microprocessor Training System to store files on audio casette (or as audio files) or separately, typically referred to in the past as Kansas City Standard (KCS) Cassette Data.

There are four great resources for emulation that exist. The required ROM files are present in this repository to run the emulation systems, but are not our creation. Give love and support the creators who put hard work into this effort! Please see how the ROMs were sourced: http://www.andysarcade.net/personal/tech/ETA-3400.htm

1. MAME (version 0.193b and later): http://mamedev.org/release.html For MAME, use the debugger in use with the following execution switches (for MAME located in C:\EMULATORS\MAME) C:\EMULATORS\MAME\mame64.exe -window -debug to allow the debugger to be used (to see the memory locations and use the cassette interface). Use the Kansas City Standard Audio interfacing python programs (included in this repository in the "KCS_Example" directory) to allow data input and output from the emulated 6800's memory using the cassette emulator feature in the debugger.

2. C Sharp 6800 Emulator:https://github.com/RupertAvery/sharp6800 (Rupert Avery, former info: https://sharp6800.codeplex.com/, https://www.codeplex.com/site/users/view/RupertAvery)

3. HyperVision 6800 IDE Assembler: http://www.hvrsoftware.com/6800emu.htm

4. Bill Lovegrove's ET-3400 Emulator: http://www.pilgrimworks.com/trainer.htm (created circa year 1999, now obsolete and will not run on modern versions of windows, available from http://www.classiccmp.org/dunfield/heath/index.htm)

Additional Resources:

Please see the manual excerpt here: https://archive.org/details/HeathkitManualForTheEt-3400MicroprocessorTrainer and here: http://www.classiccmp.org/dunfield/heath/index.htm, and details on the ET-3400 main board: http://gc.org/et-3400/

Details for the ETA-3400 I/O Accessory: http://www.andysarcade.net/personal/tech/ETA-3400.htm and http://www.vintagecomputer.net/browse_thread.cfm?id=553

The kit had the following features:

Motorola 6800 8-bit CPU clocked at 1MHz, Six 7-segment LED displays used to display address and data information, and as a visual output device, 17 push-button switches for the hex keypad, 8 LEDs for general purpose visual output, an 8-bit DIP switch for data input, a 1 KB ROM containing the Monitor program, 256 bytes RAM, buffered 8-bit data and 16-bit address lines, exposed through breadboard connectors.

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Quick ET-3400 Guide:

ACCA - View contents of Accumulator A Register

ACCB - View contents of Accumulator B Register

PC - View contents of Program Counter Register

INDEX - View contents of Index Pointer Register

CC - View contents of Condition Codes Register

SP - View contents of Stack Pointer Register

RTI - Return from Interrupt

SS - Single Step

BR - Break

AUTO - Start entering hex at specified address

BACK - During EXAMine mode, move address back

CHAN - During EXAMine mode, edit hex at specified address. During ACCA/ACCB/PC mode, edit hex in selected register

DO - Execute RAM at given address

EXAM - Start viewing hex at specified address

FWD - During EXAMine mode, move address forward

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Motorola 6800 Architecture Overview: http://www.cpu-world.com/Arch/6800.html

Motorola 6800 Basic Operation Overview: http://www.hvrsoftware.com/6800.pdf

Motolola 6800 Assembly: http://www.inf.pucrs.br/~calazans/undergrad/orgcomp_EC/mat_microproc/MC6800-AssemblyLProg.pdf

A great review on the history of modern CPUs: https://www.cl.cam.ac.uk/teaching/2006/CompArch/documents/all/trends/cpu_history.html (The 6800 Family): https://www.cl.cam.ac.uk/teaching/2006/CompArch/documents/all/trends/cpu_history.html#6809)