Mastermind DLS information

[Unaugmented]

Hello,
I have a Mastermind DLS that I purchased in the early 90's. It's been sitting in a box for 25 years. I need to have the battery pack replaced and I seem to have lost the charger. Does anyone have the specs on the power supply and/or battery pack? Thanks in advance.

[Robert Austin]

Hello, Unaugmented--the Mastermind DLS used a NiCad (!) battery pack which included 4xAA cells, which were soldered to the PCB. The console is held together by a single screw under the label on the bottom--just peel that off and open it up. Are you handy with a soldering iron? Battery packs like this are (or at least used to be) available from sources like Mouser, Digi-key, and other larger electronics suppliers. The power supply was a wall wart, DC output about 6-7.5 volts, 200-400 ma, but unfortunately I don't recall if the sheath or the center pin was ground. I did learn from our UK distributor at the time that plugging the wrong polarity into the board could trash it. I've just had a look through my design archive, but it's not there--most probably the data is stored on some 5.25" floppy discs in our storage locker somewhere. If you are into electronics though you could check the direction of current flow on the power input.

-Robert

[Mind Voyager]

That was a great machine, I wish I never sold mine. At least kept it as part of my collection.

[Unaugmented]

Hello, Unaugmented--the Mastermind DLS used a NiCad (!) battery pack which included 4xAA cells, which were soldered to the PCB. The console is held together by a single screw under the label on the bottom--just peel that off and open it up. Are you handy with a soldering iron? Battery packs like this are (or at least used to be) available from sources like Mouser, Digi-key, and other larger electronics suppliers. The power supply was a wall wart, DC output about 6-7.5 volts, 200-400 ma, but unfortunately I don't recall if the sheath or the center pin was ground. I did learn from our UK distributor at the time that plugging the wrong polarity into the board could trash it. I've just had a look through my design archive, but it's not there--most probably the data is stored on some 5.25" floppy discs in our storage locker somewhere. If you are into electronics though you could check the direction of current flow on the power input.

-Robert

Robert, to thank you so much for the info. It is exactly what I was looking for.