PostScript set printer tray for HP Laserjet M608

Hi Everyone,
We have around 7 HP LaserJet M605 printers, and a process breaks pdf files into one page .ps files. While the .ps files are created, the following code is added to the .ps file:

 

currentpagedevice /InputAttributes get 2 get
dup null eq
{ pop }
{ dup length 1 add dict copy
dup /InputAttributes
1 dict dup /Priority [0 1 2 3] put
put setpagedevice
} ifelse

 

Depending on digit/number in the "get 2 get" line these .ps files are sent to the printer and it correctly prints each paper type from the correct tray -- envelope, letterhead, plain.

We just bought new printers LaserJet M608. The same post script code additions mentioned above, does not print the envelope from the correct tray. It wants to print it from the manual tray. I kept changing the "get 2 get" line from 0-4  (4 trays) and  still the envelope keeps printing from the manual feed tray. Does anyone know if the attributes for selection of trays are different in M608 printers compared to M605? Do you have any recommendation of what I should do next to troubleshoot this issue.

I would like to add that some people were able to resolve this issue with changing the PCL settings and change the Media Source Mapping from "Standard" to "Classic". I tried the same but it did not work. 
I also get the "ERROR undefined OFFENDING COMMAND: get" for the envelope when the "get 2 get" line has the number '2' in it, and when I change the number to 1, 3 or 0, it defaults to the manual feed tray. So basically it doesn't print from any other tray other than the manual feed tray. 

Also I read that you need to complete two steps, load a postscript module on printer control library, and It associates the special media type with the tray number within the PostScript interpreter. The second module is a form setup module which requests that the PostScript interpreter select the tray with the desired media type.


I appreciate any help,

Thank you,

-Ned