To all- Please read through this- you'll be glad you did.
Gus- I know I don't post often, but that's because I always wait for something to say ;). Big news from the Feb. 97 issue of Data Storage which I have just received. An extensive feature article concerning torodial heads as the latest head design to generate two to three times less head noise and allowing two to three times higher transfer rates than conventional heads. Evidently, head noise and electrical resonance are limiting tranfer rates and recording densities. The article featured a thin-film torodial head that has a solenoid coil, rather than a flat spiral coil, that has five to ten times lower resistance and inductance than conventional inductive thin-film heads. The torodial heads support applications requiring data transfer rates exceeding 300 Mbit/s, disk speeds above 10,000 rpm, and areal densities of up to 3 Gbit/square inch. Very interesting technical paper, but enough of that, here's what's really interesting: In addition to the great specifications mentioned earlier, as well as low manufacturing costs, "the toroidal head will be particularly suitable for variable reluctance recording...Due to their very low inductance, the torodial heads will facilitate areal densities exceeding 5 Gbit/square inch to 10 Gbit/square inch and data transfer rates surpassing 500 Mbit/s when used for variable reluctance recording." So what the heck is "variable reluctance", anyway? For that you'll have to review post #319, which discussed the article in Data Storage on "keepered media". From that post, "The article went into some technical details on how the keepered media works, dicussing the concept of the variable reluctance circuit and how the keeper layer acts as a paramagnetic amplifier when its biased with a small magnetic field." But wait, there's more. The authors of this latest article are none other than Uri Cohen , Dennis Hollars, William Reed, and Robert Zubeck all of VELOCIDATA. Also, Mr. Cohen and Mr. Hollars have a patent pending claim on this new torodial head design. So there you have it, more evidence of keepered media in the works, long before any Wall Street analyst will know, or even care to know. What you are witnessing is the birth of keepered media - a new head design that will work in conjunction with Ampex's keepered media and further advance areal density, disk velocity, transfer rates and drive capacity. And you don't have to be an engineer or an astrophysist to understand what's going on. Just keep your eyes open for articles such as these and wait for the rest of the world to catch up. Maybe this is why Ampex has been so quiet and we have not heard news of expected agreements. Perhaps this has something to do with a bigger picture than merely using keepred media with existing head technology. |
