Finally managed to solve this problem. In case anyone else runs into this with the ramdisk, shorting the turboboard's battery terminals momentarily-cuts the voltage to the flash ram chips and clears out the memory contents-seems to have done no harm, all ramdisk functions perform normally again-just have to get to the the turboboard battery, which is just under the keyboard assembly. I used a short piece of wire to the + and - terminals and presto, problem solved.