http://www.bixoft.nl/english/opl_bbbm.htm
http://tachyonsoft.com/inst390m.htm
http://www.simotime.com/simoi370.htm
http://bcs.solano.edu/workarea/kanderso/CIS%2020/Tutorials/David%20Woolbright%27s%20Assembly%20Tutorial.pdf
https://www.mainframes.com/Assembler.html
https://en.wikipedia.org/wiki/IBM_Basic_Assembly_Language_and_successors
https://cbttape.org/~jmorrison/s370asm/html/index.html