Abstract: Currently available repeatable fluid dispensers require two valves. This invention eliminates one valve thus making possible a dispenser of more compact design and which possesses greater accuracy, greater precision and improved capability to dispense micro-quantities of fluid.

Abstract: Commercially available cassette cartridges which are reel-to-reel magnetic tape cartridges of a standard size and design can be converted to endless loop cartridges by replacing one of the reels with an auxiliary drive assembly including a drive hub with adjacent guides to insure positive driving in contact between the tape and the drive hub and replacing the other reel with a free wheeling tape platen with an endless loop of magnetic tape wound spirally thereon which is threaded so its innermost convolution is pulled from the hub of the platen by the combined action of the capstan drive and the forward reel drive of the recorder to insure positive tape transport without wow and flutter and returns to the peripheral tape convolution on the platen.