- Ed Thelen (working on 1401) visited Joe Feng in the RAMAC room. Joe seems to be there most Wednesdays
recording data wave forms from the RAMAC. He says that he is working on disk 41 of the 50 disks,
about 85% complete :-)) He says that his software data recovery program works perfectly with such
beautiful signals. He says that signals coming off the extremely high density of the current disks
is much more "interesting" to recover.
- The replacement (borrowed?) track position pot (all taps working) has been installed.
- Joe showed wave forms, data vs. blanks, and outside track vs. inside track. (The higher inches/second on the
outside track gives a higher signal voltage. The noise signal is about the same. Joe said that
the noise in the images shown would be decreased if the bandwidth into the scope was reduced from about 10 MHz
to 0.5 MHz ( the signal rate is about 0.1 MHz.)
- He says that his software data recovery program works perfectly with such
beautiful signals. He says that data coming off the extremely high density of the current disks
is much more "interesting" to recover - and that the validity and recovery methods are REALLY necessary
due to the much higher distortion and much lower signal to noise ratios.
| Wave form, blanks, outer track
| 
| Wave form, non-blanks, outer track
| 
| Wave form, no-blanks, inner track
| 
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