DEC 18-bit Operating Systems

So, I've been plinking around a bit with some of the operating systems for DEC's 18-bit machines. Specifically with DECsys-7 for the PDP-7, and XVM/DOS for the PDP-15. I've heard that DECsys-7 can run on the PDP-4, and in fact it "kind-of/sort-of" does. I'm wondering if anyone here knows how to get DECsys-7 working on the '4 to the point of being usable. The problem is that the PDP-4's console teleprinter was the 5-bit (ITA-2/USTTY/"Baudot") Model 28 KSR Teletype, the '7 used an ASCII machine (33 KSR, or 35 KSR). So the one key which is used in DECsys to terminate input to the text editor the delete/RUBOUT key is not present on the 28. So, you can't create any programs in DECsys on the PDP-4. There has to be something I'm missing that'll get it to work (surprisingly, the other key vital for using the editor in DECsys -- the tab key -- will work by inputting the teletype's bell code). My next question has to do with XVM/DOS; I cannot seem to get FOCAL to run. The system was built to the simulator's configuration (no UC15 UNICHANNEL, FP15, floating point, RP15, RF15, LP15, no VT15 or VP15, support for API), using SGEN I then tailored the system properly (start up with XVM and API turned on, and memory size of 128KW). I assigned the DAT slots needed for FOCAL: (-1 and -4 are already assigned by the monitor to SYA <SYS>.) ASSIGN SYA <CMG> 3,5,7,10 Trying to execute FOCAL with "E FOCAL" I get an IOPS13 error ("FILE NOT FOUND - CAL ADDR **"), and trying it with LOAD and GLOAD I get a .LOAD 3 error ("SUBR NOT FOUND"). Anyone here know the magic of how to get FOCAL to run on XVM/DOS? Thanks to any who respond. Regards, Christian -- Christian M. Gauger-Cosgrove STCKON08DS0 Contact information available upon request.