MaxiMite-DuinoMite and SimmStick.

I have recently received some private email regarding interfacing the MaxiMite and DuinoMite to the SimmStick bus, and felt some sort of explanation of events is in order to help explain the situation.

There has been some recent chat on TBS forum that reminded me that I should produce some up to date answers:

And there has been a couple of recent spin-off features from the Test-a-Mite MM-DM-CGMMSTICK1 GPIO tester board.

1) CGMMSTICK1 to Maximite-DuinoMite 26 pin GPIO Adapter.
2) Maximite or DuinoMite board, to SimmStick Adapter.

Read on…

SimmStick was designed around 1994 by Antti Lukats, a friend of mine living in Estonia. Geoff Graham (MaxiMite designer) recently credits Antti with producing the world's smallest Maximite:

In 1995 I designed a large range of SimmSticks and started selling them via Dontronics. Basically the platform was based on the then PC-XT 30 pin memory module socket, which was abundant at the time. My initial designs favoured PIC and AVR micro usage, and included a whole range of peripheral devices.

As an example, this was the world's first AVR third party prototype PCB manufactured:

It supported both the old Atmel 8051 family, as well as the new AVR family of micros.

The PCB had to be thinner than a normal PCB to fit into the memory socket, and it needed a notch up one end.

As the years rolled on, many new designs from independent third parties, added to the range. One of them was from another friend of mine, Rob Severson of the US.

Rob designed the DT209:
and gave me the PCB artwork, so I could manufacture them for all users.

His description of this product:
The DT209 I/O expansion board utilizes three I2C bus expansion integrated circuits to provide a total of 24 expansion lines. Each of the three port chips provides 8 i/o lines. These 24 i/o lines allow for input and output expansion without sacrificing any of the general control lines on the SimmBus, i.e. the lines labelled D0 – D15.

The SimmStick bus and the range of boards has declined over the years. One of the main reasons is that the memory sockets have become hard to get, however standard .1" male and female headers can be used with any thickness PCB. See:

I have been selling out my old stock of SimmStick boards at prices from $1 to $2. See:

Recently Rob Severson came up with his CGMMSTICK1, which is a MaxiMite basically on a SimmStick compatible bus. Close enough that at least we shouldn't see any blue smoke, when they are mated together.


Following on from this, Mick Gulovsen designed the MM-CGMMSTICK1-DM compatible Test-a-Mite that would allow testing of not only Rob's 30 pin bus, but also the 26 pin GPIO outputs from both the MaxiMite and DuinoMite.

Interestingly, this Test-a-Mite product has produced two new potential features.

1) CGMMSTICK1 to Maximite-DuinoMite 26 pin GPIO Adapter.

See picture below:

This is a MaxiMite CGMMSTICK1 board, connected via a blank Test-a-Mite board, to a right angle male 26 pin IDC connector.


2) Maximite or DuinoMite board, to SimmStick Adapter. See picture below:
This is a MaxiMite or DuinoMite, connected via a blank Test-a-Mite board, to a SimmStick board.

The boards pictured are a DuinoMite-Mini connected to a SimmStick DT203 LEDs and Switches board.


The Test-a-Mite boards can be purchased from:

Or we can post off the Test-a-Mite bare printed circuit board in a letter, world wide at a very cheap rate. In fact, we will do it for an extra $2.

I really don't know what the future of mating up SimmStick with MaxiMite and DuinoMite is, or even if there is a future, but as Rob has extended the useful life of the platform, I felt it was at least worth visiting the facts, and what is currently available.


Cheers Don…

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