On 5/9/07, Curtis H. Wilbar Jr. <rescue at hawkmountain.net> wrote: That seems likely. The issue at hand, of course, is the low-level format. I do not think the Pro controller is format-compatible with the RQDX3, but it might be with the RQDX1/2, from what I'm reading in this thread. AFAIK, there was only ever one model of Pro MFM controller, which shipped with the Pro/350 and the Pro/380. The Pro/325 shipped floppy-only and I think had a weaker PSU than the Pro/350, so, presumably, you could replace/upgrade the PSU or power a hard drive Indeed. I have some Pro stuff I'd love to be able to get to - been on the pile for a long time now. http://www.ibiblio.org/pub/academic/computer-science/history/pdp-11/ -ethan

Charles H. Dickman wrote: The RD32 did not work. I could not convince the standard FORMAT program to format the disk. This may be because the RD32 had 6 heads and none of the standard Pro drives had 6 heads. I then took a 3.5" NEC D3142 drive that came out of an old NEC PC and it formatted in the Pro just fine. This drive has 8 heads and 642 tracks. If the FORMAT program uses the same identification algorithm as DW.SYS, it probably sees that it has 8 heads and interprets that as an RD52Q. Is there a way to boot from the RX50 if there is an OS on the hard disk in a Pro? The only way that I could get the RX50 to boot was to remove the hard disk and then power up without a floppy in the drive and then when I got the diskette image on the screen to insert the floppy.

Jerome Fine replies: I have heard that it is possible to format an RD52 on the PRO, in addition to the RD51, so I am not surprised. How many blocks are on the NEC D3142 drive? I have a PRO350 which I have not used in many years, so I can't remember. However, I strongly tend to think it has POS installed. Consequently, when I attempted to boot RT-11, I just inserted the RX50 floppy in the RX50 drive and powered on the system. I can't remember, but I think that RT-11 booted from the floppy. The aspect that I find most interesting is that RT-11 requires a special device driver that I understand intercepts certain system and hardware interrupts such as the clock. This device driver is made resident at boot time, so something is very special with that device driver. Since there is no documentation on the PRO hardware, can anyone suggest anything? Otherwise, I will have to sort out this question from the source code. 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.

Jerome Fine replies: All device under RT-11 have a maximum of 65536 blocks. However, RT-11 is set up to use only 65535 blocks since that is all that fits into a 16 bit word. In actual practice, it is quite easy to use the extra block, but in almost all cases, it is not worth the extra effort since none of the RT-11 utilities will support you. If you have V05.03 of RT-11 or later, you might be able to use those additional 10 MB of hard drive. The command: SHOW DEVICE:DW might provide the list of available devices in the same manner as MSCP devices for the DU.SYS device driver. If you can wait a few days, I will also have a look at the code in DW.MAC and RESORC. However, the more I think about it, the less likely I feel that DEC would have allowed RT-11 partitions on the PRO hard drives. Can anyone identify the actual files on bitsavers? Is there anything there about the hard drive (is DW the correct name) being partitioned if it is larger than 32 MB? 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.

Jerome Fine replies: I just looked at the code for DW.MAC and I am certain that you are correct. There is no ability to look at blocks above block number 65535. That is what the DU(X).SYS device driver can do starting with V05.03 of RT-11. Thank you. I will have a look. However, the code for the DW.MAC device driver (the hard drive on the PRO3xx system) is included in the V05.03 distribution. There is no possibility that the code can support RT-11 partitions as with the DU(X).SYS device driver. 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.