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app:using_analogtest [2022/03/02 15:09] – [How exactly does this work?] wordsmithing; added some explanation flanapp:using_analogtest [2022/03/02 20:21] (current) – ianoid
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 ==== Test settings ==== ==== Test settings ====
  
-There are only 2 setting for the analog test. The first is to choose the **Density**. This allows you to specify the density used for the test Low (DD) of High (HD). Be sure to use the proper media type with each setting or you will not get accurate results. For PC drives that support low and high density operation, many used different sets of filters for each density. The screen shots below show the same drive set to different densities with low on the left, and high on the right. The gold line clearly shows that the characteristics of the drive are quite different for each density.+There are only 2 settings for the analog test. The first setting is the **Density**. This allows you to specify Low (DD) or High (HD) density. Be sure to use the proper media type with each setting or you will not get accurate results. For PC drives that support low and high density operation, many used different sets of filters for each density. The screen shots below show the same drive set to different densities with low on the left, and high on the right. The gold line clearly shows that the characteristics of the drive are quite different for each density.
  
 {{:app:analog_pc525_dd.png?nolink&512 }}{{ :app:analog_pc525_hd.png?nolink&512 }} {{:app:analog_pc525_dd.png?nolink&512 }}{{ :app:analog_pc525_hd.png?nolink&512 }}
  
  
-The other setting is **View**. This allows you to perform the tests slightly differently. There is a **Heads** mode that put the head in the center of the disk and performs analysis on each head (in a 2 headed drive). The bottom drive head (head 0) will be shown on the bottom half of the graph, and the top head (head 1) will be shown on the top half. The other option is **Outer and Inner Tracks** which will perform the test with the head at each end of the media. The physical spacing of fluxes differs on the outer vs inner tracks, and so this lets you see how different the drive deals with each end.+The second setting is **View**. This allows you to perform the tests slightly differently. The **Heads** option puts the head in the center of the disk and performs analysis on each head (in a 2 headed drive). The bottom drive head (head 0) will be shown on the bottom half of the graph, and the top head (head 1) will be shown on the top half. The **Outer and Inner Tracks** will perform the test with the head at each end of the media. The physical spacing of fluxes differs on the outer vs inner tracks, and so this lets you see how different the drive deals with each end.
  
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 ==== If the Noise test is a worst-case scenario, why do we care about it? ==== ==== If the Noise test is a worst-case scenario, why do we care about it? ====
  
-For the most part when reading normally structured disks, you won't care about the noise level at all. Where it comes into play tends to be with various forms of copy protection that use no-flux areas on the disk (spiral track protections and such). These kinds of areas are not that uncommon for Apple II games. The below image shows three disk renderings of the same disk rendered in drives with low, medium, and high levels of noise.+For the most part when reading normally structured unprotected disks, you won't care about the noise level at all. Where it comes into play tends to be with various forms of copy protection that use no-flux areas on the disk (spiral track protections and such). These kinds of areas are common for Apple II games. The below image shows three disk renderings of the same disk rendered in drives with low, medium, and high levels of noise.
  
 {{ :app:analog_lr_noise.png?direct&768 |}} {{ :app:analog_lr_noise.png?direct&768 |}}