Slowest-seeking floppy or hard drive ever made?

On 02/27/2012 03:41 PM, Tony Duell wrote: SA400(35track) and SA400L (40 track version) and the SA450 (two sided 40 track) they were slow and ugly in every way. But they were the only reasonable game in town in 1977 and for a while after. Step rate was 40ms or if you had a controller that could 35ms was as fast as it could go. You had to wait an additional 40ms for the head to settle after stepping. The Tandon TM100 was a major improvement over shugart. Same for MPI. The bulk of the 5.25 inch drives never got faster than 6ms/step. The 3.5" most of them were 6 or even 3mS. I still run enough non-PC systems with 8, 5.25 and even 3.5" drives to appreciate what just a faster step rate can buy in response time if the OS knows that. Another slow poke hard disk was the SA1000, it's used a stepper. By time Tandy got into the act with a disk the market had already started to turn on shugart for the problematic SA400. But they used it anyway for cost and the first year with the EI and disks (never mind DRAM timing issues) was seriously painful as the data jitter on some SA400s made disks unreadable using the 1771 internal data separator. Using the internal 1771 data sep was stupid to the extreme but the SA400 really was bad. I was there for all that. It wasn't pretty. Allison