Jerome Fine replies: Note that the RK05 media could be formatted by the PDP-11 operating systems. One of the "tests" I always used under RT-11 was to make a duplicate of a pack and then run BINCOM. If there were no errors with BINCOM, then the original media was OK. BUT, after constant use for a month or two, I found that the system media (SY:) on the production system would start to lose its format - for whatever reason that would happen. Whoever wrote BINCOM (as opposed to DUP) left out all the extra code to read a "difficult" block the extra number of times needed if it could be read. Thus, "COPY/DEVICE RK0: RK1:" would work (using DUP), but not "DIFF/BIN/DEVICE RK0: RK1:" (using BINCOM). Thus it was possible to recover "difficult" blocks before they were gone, FORMAT the original RK0: media to whatever standard was required and copy the duplicate data back to RK0: and continue. Thus, I have a question to ask. What was the difference between the RK05 that can be formatted and the RL01/RL02 which can't - other than the method that DEC chose to lay out the servo tracks? How much more would it have cost to allow the RL01/RL02 drives the ability to format in the field just like the RK05? And could the problem have been more because of the fact that the RL01/RL02 became a "DEC owned" product just like the attempt by DEC to pretend that all RX01/RX02/RX50 floppy media should be purchased from DEC as well? The format of the RX01 was identical to the IBM SSSD format. Thus, other than the fact that DEC "forgot" to mention that fact and that DEC also "forgot" to include the necessary few bits of hardware to allow the drive to format media off-line (3rd party manufactures of look-alike RX01 drives), many other manufactures made floppies that were pre-formatted. However, I do seem to remember that DEC almost always seemed to charge the highest price for "genuine pre-formatted" RX01 media. From my point of view, it seemed to say a lot about a company that would charge up to 10 times the cost of non-formatted media when most other companies charged only a small (about 10%) premium. The RX02 media was identical to the RX01 media. Without going into all the details, the RX02 drive could flip the density on the media, BUT it had to be formatted FIRST. On the other hand, some media did develop "difficult" blocks. In that case, the FORMAT command in RT-11 could be used and the "difficult" blocks were usually, but not always, eliminated. Again, the DEC RX02 drive and controller could not FORMAT an RX02 from scratch, but almost every 3rd party manufacturer made a controller/drive unit which could. The RX50 media was almost identical - except that a few DEC systems could format RX50 media. While DEC charged to usual (1000%) premium for RX50 formatted media, a PC could actually do the job with a 5 1/4" HD drive. The RX33 media could be formatted in the field. They were identical to the format of the 1.2 MByte HD PC floppies - so DEC finally seemed to decide that the RQDX3 should be able to format the media - when it was no longer needed - 1.2 MByte HD PC floppies were in great supply and DEC would have looked .... charging its usual 1000% markup for the product. Just in case you forgot, what might the extra cost of an RL01/RL02 drive have been that could do the FORMAT command? Sincerely yours, Jerome Fine -- If you attempted to send a reply and the original e-mail address has been discontinued due a high volume of junk e-mail, then the semi-permanent e-mail address can be obtained by replacing the four characters preceding the 'at' with the four digits of the current year.

Umm, you do know that 120Gb IDE hard drives are $120 or less. The trick is figuring a way to USE a 120Gb drive in place of a RL02... -Lawrence LeMay

At 09:01 PM 5/20/02 -0500, Lawrence LeMay wrote: Yup. I've never had to buy a RL cartridge, though, so I've no idea how much they cost. (All my RL disks were VMS distribution disks recycled onto my PDP-8.) -Rick

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