The MasterAdapter available for sale here is an authentic reproduction of the Schnelder Systems MasterAdapter created in the early 1990's.  This device allowed the simultaneous use of the TurboMaster CPU and a GEOram cartridge or Commodore  REU.

This device has been fully tested and proven to function with a stock TurboMaster CPU and original Berkley Softworks 512K GEOram cartridge operating under the GEOS 2.0r operating system on a stock Commodore 64 computer.  It has further successfully been tested with a Commodore REU.

The original design concept for this interface was to allow the user to use either a Commodore REU (ie: 1764 Commodore Ram Expansion Unit) or the GEOram cartridge from Berkley Softworks.  Out of the gate, the original GEOram cartridge worked fine, however during Schnedler Systems development, considerable problems were encountered during the development process to get the Commodore REU to function correctly.

At the end of Schnedler Systems involvement in Commodore technology, the MasterAdapter project was abandoned before development had been completed.  

All of the remaining information that exists for this device (including the final driver diskette that was created for the MasterAdapter) can be found in the files section for this item.  Please feel free to download any of the files you would like at no charge.

An instruction manual has been created to assist you in the deployment of your MasterAdapter, and can also be found in the files section for this item.

No compatibility issues have been found between Turbomaster/Masteradapter/GEOram and differing version of the Commodore 64 mainboard.  This however cannot be said for REU functionality.  Testing to date has shown that this combination functions well with the following mainboards (250466, 250469.Rev.3 ,250469.Rev.4, 250469.Rev.A).  The older the board, the more artifacting is seen.  Most long boards show varying degrees of artifacting, some so bad that it is not usable. 

It should also be noted that in order to take advantage of the REU functionality, you will HAVE to HAVE a MA/U18 chip installed in your Turbomaster CPU.  This was a special replacement PAL chip that was specifically modified for MasterAdapter compatibility.  I have managed to obtain a limited supply of these chips.  Please check your TurboMaster CPU to see if your U18 chip has the letters "MA" on it.  If it does, you do not need to purchase one from me.  Please don't buy one if you don't need it, as I only have a limited supply of them.  Once they're gone, they're gone.

Because this device was really still a pre-production prototype, I cannot guarantee functionality with all of the combinations that can be had.  There are many differing types of REUs, reproduction GEOram cartridges, and MANY differing C64 board versions.  Your results may differ. 

All MasterAdapter boards sold here through the shop are hand made, and tested prior to shipping.  I will test both the GEOram and REU functionality before shipping.  As a result, there will be a bit longer of a delay in shipping this item as quite a bit of effort will go into it before I will ship to ensure you get the best quality and tested product that can be provided.