Eca Vrt Disk 2012 Dvd Iso Full35
Giraldo Allain
I wrote a fast loaded for the C64 back in the day too. I had access to a print out of the source code for the 4040 disk drive and using it as a guide I disassembled the 1541 roms and figured out what was going on. My fast loader worked using the standard cable. The hardest part was getting around the fact that the screen hardware stole cycles from the CPU. So my code had to look at the current raster value and pause when it was on a line that stole cycles from the CPU and then run full speed again when it could (other loaders got around this by turning off the screen). It was a lot of fun but also very frustrating debugging code inside the 1541 when it crashed.
The drives waited until the source disk was inserted and the drive door closed.. Then the destination drive waited until a disk was inserted and the drive door closed and they then started duplicating the disk..
I could have sworn there were some SATA Dell disks listed on their, or I am probably thinking Seagate Constellation SAS. From my experience as long as you have an HBA with decent QD (min LSI 2308), and over the top Enterprise PCIe SSD NVME, 6TB SATA 7200 disk have worked out just fine. Had flying success with high-end PCIe and 4x 6TB SATA per host. Works great. However 4TB SAS really is the way togo. IMHO
HP seems to have the best capability to scale VSAN, with the SL4540, 35 LFF drives, and a controller and 6TB SAS drives on the HCL. And even then, the largest HP SDD on the VSAN HCL is 1.6TB, when you should have 2.1TB per 42TB disk group.
Let's say it's a minimum 3 node cluster, that's 216 TB before overhead. It work load can consume that much space, but still perform well with only 6 sockets in the cluster? It seems like with disk that dense, you would run out of compute power before you could fill it up. Is it a few VMs that are massive? A lot of little VMs that don't consume much CPU? Something else I'm missing? Thank you, Zach.
Let's say it's a minimum 3 node cluster, that's 216 TB before overhead. It work load can consume that much space, but still perform well with only 6 sockets in the cluster? It seems like with disk that dense, you would run out of compute power before you could fill it up. Is it a few VMs that are massive? A lot of little VMs that don't consume much CPU? Something else I'm missing?
The VSAN HCL is pretty slow to update. Since release of 6.0 i don't think any NVME cards or SATA disks have made it into HCL yet. Of all the parts on the HCL, raid controller is most important followed by SSD. I'm not sure how important magnetic disks are to the HCL so far. The generalized thing I keep reading is that if you don't use enterprise/quality parts or try to cheap out with consumer level parts, things will suck and data will be lost. In particular, SSD drives will need power loss protection capability which isn't found on many consumer level drives.
In general, deleted files don't go anywhere. They remain on the disk exactly as they were until they happen to get overwritten. When they are deleted, a link to it is simply removed from the file system structure.
There are often debates about if data can still be recovered after a single overwrite. The fact is this has never been publicly done on a modern disk. Peter Gutmann wrote a paper about this, and one of the methods is named for him. You can read his paper here: pgut001/pubs/secure_del.html
The Gutmann method is an algorithm for securely erasing the contents of computer hard disk drives, such as files. Devised by Peter Gutmann and Colin Plumb and presented in the paper Secure Deletion of Data from Magnetic and Solid-State Memory in July 1996, it involved writing a series of 35 patterns over the region to be erased.
Most of the patterns in the Gutmann method were designed for older MFM/RLL encoded disks. Gutmann himself has noted that more modern drives no longer use these older encoding techniques, making parts of the method irrelevant. He said "In the time since this paper was published, some people have treated the 35-pass overwrite technique described in it more as a kind of voodoo incantation to banish evil spirits than the result of a technical analysis of drive encoding techniques".[1][2]
The delete function in most operating systems simply marks the space occupied by the file as reusable (removes the pointer to the file) without immediately removing any of its contents. At this point the file can be fairly easily recovered by numerous recovery applications. However, once the space is overwritten with other data, there is no known way to use software to recover it. It cannot be done with software alone since the storage device only returns its current contents via its normal interface. Gutmann claims that intelligence agencies have sophisticated tools, including magnetic force microscopes, which together with image analysis, can detect the previous values of bits on the affected area of the media (for example hard disk). This claim however seems to be invalid based on following thesis - Data Reconstruction from a Hard Disk Drive using Magnetic Force Microscopy [5]
Although you didn't ask, it should be pointed out that shred overwrites a target using three passes by default. This is unnecessary. The myth that multiple overwrites is necessary on hard disks comes from an old recommendation by Peter Gutmann. On ancient MFM and RLL hard drives, specific overwrite patterns were require to avoid theoretical data remanence issues. In order to ensure that all types of disks could be overwritten, he recommended using 35 patterns so that at least one of them would be right for your disk. On modern hard drives using modern data encoding techniques such as EPRML and NPML, there is no need to use multiple patterns. According to Gutmann himself:
(See other answers for additional advice regarding wiping data. But mainly, keep in mind that the need for doing multiple passes is largely a legend, which had a grain of truth in old technologies but is not at all relevant to 21st century media. A simple overwrite with zeros is just as good. And conversely shred doesn't touch reserve sectors which may be readable with some extra effort to bypass the normal working of the disk controller, so use the disk's secure erase if it works.)
Looking at this from the other point of view, with the ever-increasing data density on disk platters and a corresponding reduction in feature size and use of exotic techniques to record data on the medium, it's unlikely that anything can be recovered from any recent drive except perhaps a single level via basic error-cancelling techniques. In particular the drives in use at the time that this paper was originally written are long since extinct, so the methods that applied specifically to the older, lower-density technology don't apply any more. Conversely, with modern high-density drives, even if you've got 10KB of sensitive data on a drive and can't erase it with 100% certainty, the chances of an adversary being able to find the erased traces of that 10KB in 200GB of other erased traces are close to zero.
if you inserted a floppy disk "upside down" the Apple IIe would make a hideous noise like a vacuum cleaner. Why? What a shocking design; it scared the heck out of me as a newb. Was it usual to do that to a user? I never really recovered from that; I was put off computers for the rest of high school.
The Apple will keep track of how it has moved the head in and out since it forced it to the end stop, and will thus generally know where it expects the head to be. Because each track of a formatted disk includes markers that identify it, the Apple will generally assume that if it thinks it's on e.g. track 12, and it sees a marker for track 12, then it is in fact on track 12 and it can proceed on that basis.
The noise you heard was from step 4. When trying to access a valid formatted disk, the Apple will generally not need to run the head against the end stop, but the back side of most disks won't typically be validly formatted.
It also had to be built to a budget though, so they couldn't design it to prevent every instance of user error from causing problems without the cost ballooning. Apple computers were already relatively expensive for their time and they'd just have priced themselves out of the market if they'd tried. So yes, they probably knew what would happen if you put the disk in upside down, but since it wouldn't break anything permanently it wasn't seen as worth the cost of fixing.
The short answer is they did it to save money. They could have made the drive behave better when a disk is inserted upside down, but that would have required larger ROM chips to store the firmware or more expensive drives and controllers to detect the problem.
Also, there was no different operation between "upside down" or not. Simply as the drive had no way to detect which was the'right' side (*1). In either case the II tried to read the disk. The difference may eventually have been that there was nothing to read on the back side (of the disks you used), resulting in an endless attempt to read.
Because it's an awesome simple design. The head ist moved across the racks by a spiraled disk. Turned in one direction the head moves outward toward track 35, when reversed it turns toward track 0. After power up/reset the head may be positioned at any of the tracks. So it needs to move in a way to get to a defined point - with track 0 being a desirable goal.
There is no way to tell on what track it is, so the computer moves the head back toward track 0. Now, they could have installed a sensor telling when track 0 is reached. Except, Woz tried to minimize parts and logic, so he devised a way to do it without a sensor and electronics. So the spiral disk was made in a way that the head simply hits a stop were track 0 is supposed to be. Now the controller can always turn the head back for full 35 tracks. It'll move until it hits the stop. after that the disk continues to move (until all 25 steps are done), but the slider moving the head just jumps the spiral track, as the head can't move anymore.