Photo: Red Hill.
Alps Electric DRR-40
A very odd little drive. Alps Electric haven't made hard drives for many years, though they continued manufacturing floppy drives for a long time, and laptop touchpad pointing devices for years after that, but these little 40MB units were always good performers. They were very small and thin, especially by the standards of the day, and used an odd-ball small power connector like a 3.5 inch floppy drive. As usual with early IDE drives, they didn't master/slave well. There were identical-looking Alps 105 and 200MB drives too.
The Alps drives were some of the first ones to use sector translation to get more than 1024 tracks on a disc. This used to cause troubles with the IDE 'identify' command, which was employed by auto-detect BIOS or drive utility programs to ask the drive what its correct parameters were (heads, cylinders and sectors per track). The Alps 40 returned its actual parameters, where more recent drives returned their logical parameters. So, if you auto-detected an Alps 40 using a standard pre-LBA BIOS, you had to halve the cylinder count and double either the heads or the sectors per track. (Or, for that matter, use any other three CHS figures that added up to the correct size and didn't violate the CHS maxima: 1024 cylinders, 16 heads, 63 SPT.) It's been some years since we've seen one of these.
|Estimated data rate||15 Mbit/sec||Spin rate||3600 RPM|
|Seek time||19ms||Actuator||Voice coil|
|Platter capacity||10.7MB||Interface||IDE mode 0|
|AT drive type||17||Form||3.5" quarter-height|
|DRR-40||42MB||2 thin-film heads|