im away on vacation, but can try to talk you thru PG stuff to make a copy...
put pmc i/j disk in the pig
press and hold 'load' till screen flashes...wait for it to load to 'fapt ladder' screen...
depending on your disk version-
hopefully you will get in purple at bottom of screen 4 options- older stuff only gets 2 and editing is mnemonic only- ill assume you have newer firmware
think R0 is programmer hit that and youll get main screen
toggle F9 on, plug in pcwriter (think it goes in CN0), think '3' is the command for read ladder from fd/pc/cassette
it will ask uou to enter 0/1 or yes/no for cassette type, and then should shift the green light to the cassette socket, and start counting addresses on screen as it loads

to save, if you want a new 'work' disk for ladder programs only, put a blank disk in either drive(0=top/1=bottom drive) hit NL a couple times to return to the main fladder screen with purple prompts at the bottom, hit R3 make sure your firmware disk is removed in case you select wrong drive- dont want to erase it assuming you removed firmware disk from top drive and put a blank in(write protect hole blocked) back in top drive- type DINT 0 (disk initialize- like 'format' in DOS) and hit NL key- think it confirms you want to format it- say yes... when done, you can type FDLI L (for drive 0- optional, FDLI 0,L or FDLI 1,L for drive0/1) to list whats on it(like 'dir' in DOS) should list nothing but a bunch of free area... your firmware is still in memory, so you can type 'SAVE' to make a backup of the firmware- it will ask you which drive to use (has to be done before files are written to disk, as firmware will occupy like the first 16-18 file blocks on the disk), then FDLI L again to make sure its there...

NL back to main screen, hit R0 again, turn off F9, turn on F7(i think- whatevrs for FD in/out) select 4(i think- whatevers for output ladder data to...)
hit NL, it will ask you for 'save as'... type OK @Filename NL, it will write to disk(if using drive 0 , the 0 is optional, if using drive 1, type OK 1@filename...

if you have the newer software(likely), NL back to main screen, hit R1 for edit, use the R0 key to scroll between ladder/nmemonic/symbol/etc pages...if you get stuck on the ladder page- use the top left blank softkey to escape back out... if R1 isnt on the purple menu, you have early software, and will need to go to R0 screen, then select 0 or 1(i forget- the first listed) to edit, and you will get mnemonic/symbol only stuff by flipping thru R0 choices... editing in mnemonics kinda sucks, but you can hit F4 key to flip between mnemonic and graphic ladder display.

think thats kinda correct- try and see, should be close...I'm guessing maybe you didnt get the firmware to 'load' and were stuck there- ive found cryptic as the commands are (SAVE = format/s in DOS, DINT= format in DOS, FDLI L ( the L after is for pausing at each page- if F8/F9 are on) = dir/p in DOS) and using 0/1 instead of A:/B: for drive names, that the old PG software is surprisingly fast for editing...the toggling between symbol/adresses sucks, but otherwise, its pretty fast and easy-

forgot one- if you list a disk and say theres 20 files listed, and you want to erase file #17 from drive 1-
type SCRA 1:17 it will prompt you to confirm,
FDLI 1,l again to relist, you'll notice * where 17 was, but disk blocks still occupied... type COND 1 to condense drive 1(kinda like defrag in dos, packs everything back into contiguous sectors of the disk- its slow as heck...)

hope this helps a little with operating the pig...