Added proper clocking of VT100 keyboard UART, allowing us to restore the proper CPU speed (2.7Mhz) and maintain the correct cursor blink rate

docs/dec/pdp11/unix/README.md

@@ -0,0 +1,76 @@
+Unix v7 for the PDP-11
+----------------------
+
+Here's the result of following along with [How To Emulate Unix V7 Using Simh (2015)](http://www.jdpressman.com/2015/11/27/how-to-emulate-unix-v7-using-SIMH-(2015).html),
+which also draws from an old [README](http://ftp.fibranet.cat/UnixArchive/PDP-11/Boot_Images/README).
+
+	[~/Projects/GitHub/other/simh] cd kits
+	[~/Projects/GitHub/other/simh/kits] ls
+	1401_fortran_autocoder.tgz     decsys.zip                     iu7swre.zip                    s3scp.zip                      uv6swre.zip
+	1401koans.zip                  dms8.zip                       lispswre.zip                   sim8swre.tar.Z                 uv7swre.tar.Z
+	211bsd.dsk.gz                  dos11.zip                      os8swre.tar.Z                  sim8swre.zip                   uv7swre.zip
+	BASIC_CAPS-11_distribution.zip dos15.zip                      psaltair.zip                   simh-imp-1973-sw-kit.zip       xvmdos.zip
+	adss15.zip                     esixswre.tar.Z                 rdosswre.tar.Z                 swtp6800-swk.zip               xvmrsx_simh_kit.zip
+	caps11_system.zip              focal15.zip                    rstsv7gen.tar.Z                tss8.zip                       zrdos75.zip
+	caps8_all.zip                  foclswre.tar.Z                 rstsv7swre.tar.Z               utils.zip
+	ceo1401.zip                    ibm1130software.zip            rt11swre.tar.Z                 uv5swre.tar.Z
+	ceoaltair.zip                  ibsys_kit.zip                  rte6200.zip                    uv5swre.zip
+	ddt1.zip                       iu6swre.zip                    rtv53swre.tar.Z                uv6swre.tar.Z
+	[~/Projects/GitHub/other/simh/kits] mkdir unix
+	[~/Projects/GitHub/other/simh/kits] cd unix
+	[~/Projects/GitHub/other/simh/kits/unix] unzip -d uv7 ../uv7swre.zip
+	Archive:  uv7swre.zip
+	  inflating: uv7/AncientUnix.pdf     
+	  inflating: uv7/unix_v7_rl.dsk      
+	  inflating: uv7/README.txt          
+	[~/Projects/GitHub/other/simh/kits/unix] more uv7/README.txt 
+	THE ENCLOSED SOFTWARE IS PROVIDED UNDER LICENSE.
+	
+	DO NOT USE THIS SOFTWARE UNTIL YOU HAVE READ THE LICENSE AGREEMENT.
+	BY USING THE SOFTWARE (OR AUTHORIZING ANY OTHER PERSON TO DO SO), YOU
+	AGREE TO ACCEPT AND ABIDE BY ALL THE TERMS OF THIS LICENSE AGREEMENT.
+	[~/Projects/GitHub/other/simh/kits/unix] cd uv7
+	[~/Projects/GitHub/other/simh/kits/unix/uv7] ../../../BIN/pdp11 
+	
+	PDP-11 simulator V4.0-0 Beta        git commit id: 592deb8f
+	sim> set cpu 11/45
+	Disabling XQ
+	sim> set tto 7b
+	sim> att rl unix_v7_rl.dsk
+	sim> boot rl
+	@boot
+	New Boot, known devices are hp ht rk rl rp tm vt 
+	: rl(0,0)rl2unix
+	mem = 177856
+	# mkdir /tmp
+	# chmod 777 /tmp
+	# mkdir /usr/dmr
+	# chown dmr /usr/dmr
+	# chgrp 3 /usr/dmr
+	# Restricted rights: Use, duplication, or disclosure
+	is subject to restrictions stated in your contract with
+	Western Electric Company, Inc.
+	Thu Sep 22 05:48:50 EDT 1988
+	
+	login: dmr
+	$ ls
+	$ pwd
+	/usr/dmr
+	$ cd /
+	$ ls -l
+	total 643
+	drwxrwxr-x 2 bin      2512 Sep 22 05:32 bin
+	-rwxr-xr-x 1 bin      8986 Jun  8  1979 boot
+	drwxrwxr-x 2 bin       160 Sep 22 05:47 dev
+	drwxrwxr-x 2 bin       336 Sep 22 05:48 etc
+	-rwxr-xr-x 1 sys     53302 Jun  8  1979 hphtunix
+	-rwxr-xr-x 1 sys     52850 Jun  8  1979 hptmunix
+	drwxrwxr-x 2 bin       320 Sep 22 05:33 lib
+	drwxrwxr-x 2 root       96 Sep 22 05:46 mdec
+	-rwxr-xr-x 1 root    50990 Jun  8  1979 rkunix
+	-rwxr-xr-x 1 root    51982 Jun  8  1979 rl2unix
+	-rwxr-xr-x 1 sys     51790 Jun  8  1979 rphtunix
+	-rwxr-xr-x 1 sys     51274 Jun  8  1979 rptmunix
+	drwxrwxrwx 2 root       32 Sep 22 05:48 tmp
+	drwxrwxr-x12 root      192 Sep 22 05:48 usr
+