Jerome Fine replies: I have one working (or at least it was about 3 years ago when it was last in active use) SMS-1000 backplane (and power supply) with built in hard disk drive (I can't remember the size - about 10 to 30 Megs). If I remember correctly, the backplane is only 5 quad ABAB slots which is OK for very limited things. But the design was far superior to the BA23, so I used it for a while. My box has a single 8" floppy which is DSDD in capacity for a total of 1976 blocks. The drive is also set up the detect SSDD floppy media as well as DSSD and SSSD media. BUT, the device type is for the MSCP emulation. AND the DSDD interface switches from side 1 to side 2 for each cylinder (or track since there is only one double-sided surface) within the firmware. Since this behaviour is outside the control of the device driver (MSCP is DU:), the use of DSDD media is quite a surprise as compared to the RX03 implementation on a DSD 880/30 which uses the same floppy media, but uses the whole first side of the media followed by the second side of the media as programmed within the DY(X).SYS software device driver in RT-11. If someone wants a further explanation because I did not explain things well enough, please ask. The key point I am making is that when I wanted to make a bootable media for the SSDD floppy, I was able to issue the command: COPY/BOOT:DU DY0:RT11XM.SYS DY0: when I had set up all the files on the RX02 floppy (DEC or DSD would not matter) prior to using the floppy to be bootable on the SMS-1000. I then copied a number of additional files onto a second floppy SSDD which I wanted to place on ONE DSDD floppy on the SMS-1000. After I booted the SMS-1000, I set up a VM: (memory disk in about 2 Mbytes of memory with 1976 blocks. I copied the first floppy SSDD onto the memory disk, did a SQUEEZE and a BOOT. That way, I could then insert the second SSDD floppy with the additional files DSDD 8" floppy and COPY/DEVICE VM0: DU1: which gave me an 8" DSDD floppy with 1976 blocks for the SMS-1000 which was bootable on that hardware and had most of the files I wanted for development and testing. Eventually, I backed up the hard drive onto floppy (I think it had RSX-11) and placed RT-11 on the hard disk. Eventually, I suspect I will bring the system back to life and play some more. It is almost identical in size to a BA23, but a little lighter and much easier access. If I add an ESDI controller, I can have 600 MBytes and still have 3 quad slots available with a dual 11/73, a dual 2 MBytes memory. Since the access is so simple, I can at various time add any number of boards. And with a 600 Mbyte ESDI hard drive that I can WRITE PROTECT and backup directly onto another 600 Mbyte hard drive (both on a PC power supply), there will be more than enough hard disk storage for RT-11 (the ESDI Sigma controller allows up to 4 drives). NOTE that I said play. With the Eratz-11 emulator running already at about 10 times the speed of a real DEC 11/73 on a high end Pentium III and only a change of the chip required to run at 20 times the speed (or even more), I doubt that the real DEC CPUs will be attractive much longer. Certainly, I will still keep a real DEC 11/73 CPU available to test things as an additional verification when I want to be absolutely sure, but I have yet to find ANY problems with the Eratz-11 emulator. As soon as I finish my tax returns and clean up a few other things, I want to make Y2K patches available for hobby use for V5.3 of RT-11. Is anyone interested? If you read this far into this e-mail, then you must be a PDP-11 user (addict like I am). I know a few of you like RT-11 as well, but I don't know how serious you feel about Y2K patches? Please respond (either on list or off - V5.3 was released in 1985 and qualifies under the 10 year rule). Sincerely yours, Jerome Fine RT-11/TSX-PLUS User/Addict