CD-ROM on RT-11?

"Zane H. Healy" wrote: Jerome Fine replies: As Zane may remember, under Windows 98, when I use the E11 command: MOUNT DU1: CDROME: I am able to see almost the whole CD under RT-11 EXCEPT the first 64 decimal (100 octal) blocks. Can anyone comment on this aspect? To help anyone understand, when I boot RT-11 under E11 under Windows 98, the CD (having used the above command under E11) will appear as 20 RT-11 partitions of exactly 65536 "blocks" (32 MBytes) each - assuming that the CD has been written to the highest possible "block". Each "block" will still be 512 bytes even though on the CD the "sector" size is 2048 bytes. This means that the CD is divided into partitions of exactly 16384 "sectors" that are 2048 bytes each - even though RT-11 will see it the other way (i.e. 512 byte blocks). However, the first 64 blocks of 512 bytes are NOT readable under Windows 98. I have NEVER had the ability to use the same CD in a CDROM drive under RT-11 on a real PDP-11, but I get the impression that under that set-up, the first 64 blocks can be read. In that case, it would even be possible to have the real PDP-11 do a hardware boot from partition zero is everything on the CD was set-up correctly. Can anyone comment on this question? ALSO, I noticed a reference in previous post in respect of the notation used to write to a specific block on the destination. Tom suggested: dd if=/dev/rz4c ibs=64k obs=64k | cdrecord -dev 3,5,0 -speed=2 - but I would appreciate some idea of what the actual syntax is for the command? By the way, Doc, I have downloaded the dd.exe file - thank you. Of course there was no documentation. Perhaps that is available somewhere as well? Also, can I use this technique to "Burn" a CD that has already had the first portion written with an ISO file structure? Was this how Tim Shoppa prepared the RT-11 Freeware CD? If I seem totally confused by the nature of the questions I am asking, you are correct! 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.