Basic process for building a bootable TU58 image of RT11.

First, download the latest version of SIMH - version 4.0 (you need it for the TU58 Support)

General information and links:  http://simh.trailing-edge.com/
Prebuilt Windows Binaries	https://github.com/simh/Win32-Development-Binaries
Software Kits:			http://simh.trailing-edge.com/software.html

List of available binaries:	https://github.com/simh/Win32-Development-Binaries
	Go to the bottom of the list of "Current" entries, click on it.
	Ignore the "Sorry about that" message, and click on the Download button on the right
	Extract PDP11.EXE - that should be all you need, though I recommend playing
	around with the IBM 1410/7010 emulator, I7010.EXE for a COMPLETE change of pace.  ;)
	Put pdp11.exe somewhere handy

Download the RT11V5.3 images:
	http://simh.trailing-edge.com/kits/rtv53swre.tar.Z 
	The RL02 disk image you need is in folder Disks

Build an RL02 "Working copy"
	http://decuser.blogspot.com/2015/12/tutorial-setting-up-rt-11-v53-on-simh.html

Initial.ini file I used:

	set cpu 11/73 128K
	set tto 8b
	set rl0 writeenabled
	set rl0 rl02
	attach rl0 rtv53_rl.dsk
	set rl1 writeenabled
	set rl1 rl02
	attach rtv53_rl_backup.dsk
	set rl1 badblock
	boot rl0

(You will need to use CTRL+E to go back to SimH to switch disks.  I created my "working disk" disk by simply copying one of the others).

Create an empty TU58 image file, of 512 blocks @ 512  (I just used cygwin "dd")

The boot.ini file I used (rl.dsk was my "working copy" == working.dsk in the web page instructions)

	set cpu 11/73 128K
	set tto 8b
	set rl0 writeenabled
	set rl0 rl02
	attach rl0 rl.dsk
	set tdc enable
	attach tdc0 dd.dsk
	boot rl0

I then executed the following RT11 commands to build my TU58 image

        INITIALIZE DD0:
	COPY RT11SJ.SYS DD0:		[Or RT11XM.SYS for the Extended monitor]
	COPY SWAP.SYS DD0:
	COPY DD.SYS DD0:		[Or DDX.SYS for the extended monitor]
	COPY TT.SYS DD0:
	COPY PIP.SAV DD0:		[For general file operations]
	COPY DIR.SAV DD0:		[For DIRectory command]
	COPY RESORC.SAV DD0:		[For SHOW commands]
	COPY/BOOT DD0:RT11SJ.SYS DD0:

I then tested my image under SimH

	set cpu 11/73 128K
	set tto 8b
	set rl0 writeenabled
	set rl0 rl02
	attach rl0 rl.dsk
	set tdc enable
	attach tdc0 dd.dsk
	boot tdc0

	(It complains about not finding STARTS.COM - not a problem)

I tested this image under both SimH and a real PDP-11/24.

But, IF you are building RT11SJ, you are NOT done yet.  

The J11 on the S100 bus has a "quirk".  At first when I tried to boot RT11SJ
it trapped thru location 4, causing a halt at location 0 because location 4 was 0 (@000002 halt).

[Note:  The "mapped" monitor, RT11XM.SYS does NOT require this patch - does not even support it.]

I figured it might be a sizing issue or some unexpected device register.  So, I went poking around
the RT11 Installation manual (actually for RT11V5.6 -- but close enough to V5.3, and the same kind of thing 
exists in V5.1).  Section 2.6.20 reads:

"If your PDP–11 does not generate a bus timeout trap when the running program
accesses location 160000, the RT–11 bootstrap may assume that you have an LSI–11
with the MSV11–DD memory option. The bootstrap assumes that there are 30K
words available for the operating system. If this is not the case, RT–11 will not load
into memory properly. However, if you install the following customization in your
monitor, the bootstrap will never look for more than 28K words of memory. You
cannot install this customization in a mapped monitor."

Well, sure enough, when I wrote a little program to access memory location 160000 it did NOT trap.  
This is because the PDP11V2 PLD maps location 160000 (0xE000) to a valid port - it does not abort.
Indeed - it is the propeller console.  OOPS.  It would be nice if we can get that to change, but
if it did change, it would require changes in the U25, the monitor and maybe even the hardware.

So, we need to patch RT11SJ.SYS as indicated above.

First, we need to look at RT11SJ.MAP and find location ..28KW.  In version 5.3, it is at 001142. 
(Apparently the V5.3 SIPP program doesn't deal with symbols, or, more likely, they were stripped
out of RT11SJ.SYS)

So, after booting from the RL disk with DD0: available (say, using boot.ini) we do:

.RUN SIPP DD0:RT11SJ.SYS/A
Base? 0
Offset?  1142

 Base       Offset      Old  New?
   000000     001142  170000  160000<CR>
   000000     001144  001402  ^Y<CR>

Then:

.COPY/BOOT DD0:RT11SJ.SYS DD0:


JRJ