Ahh, hopefully this is not too, too late for you.
You don't say if you have any resources, at all.
And you're on the wrong website looking for us dinosaurs. We're all mostly offshore on this really lovely island in a special park. You know the park.
We don't have no superuser's, we have qsecofr.
Here comes a whole kettle of fish, and keywords and commands and buzzwords to google you in the right direction on ibm's website.
Know mention of any paper manuals for the system and software development ? Maybe on someone's closet or book shelf or the back of the computer room. Or if any software compilers are available in C, or COBOL, or RPG on your system. Or if any dinosaurs are still somewhere down the hall or basking in the break room, to ask questions of.
Fear not, based upon your vague job specification, let us assume you truely need only raw data entry -- no proofing nor any validation, just type and dump.
Well, there's an app for that.
And tons of resources, a whole library of reference manuals, a set for each and every major version of the OS. Yep, a lot of trees /forests died for them there pseudo-mainframes. Since that library is online at ibm.com I leave it to you to google their website with the search term
site:ibm.com +as/400 +manuals
Or iseries instead of as/400. Particularly noteworthy are the series of books known as the "redbooks" -- tips and tricks and some samples.
But, you have no time for reading through 81/2" - 11" - 3" thick manuals. Although the redbooks are mostly 1/4". Even though they're online and also downloadable as 5 MB pdf's to your laptop for late night entertainment when you have trouble getting to sleep.
Let's assume that your system still has the basic development facilities. You will need the book on data definitions ( DDS ) so you can define a fixed length record layout of fields for a physical file, yes, as opposed to a logical file ( index over that physical file ). You will want the file to have a primary index so define key fields for customer number or order number or what have you. That's where PDM enters the picture, using this online source code editor management system.
All programs make access of files via it's internal definition, kinda like the resource fork of a mac file -- compiling your DDS specifications to create an empty file. crtpf ( create physical file ) and dltf ( delete file ) and clrpfm ( empty physical file member ) and crtdupobj ( create duplicate object ) -- all come to mind.
About 20 minutes of planning and editing.
****remember****
Just type a command on the command line of your menu screen and press F4 to get a wizard for entering the command parameters, press F1 for additional help display.
****play safe****
Most commands refer to library, don't leave the library parameter blank.
You will be doing all of your work within what they call a library ( sort of a home folder ) storing your source code inside of source members inside of source files inside of your library ( sort of member equals pc file and source file and library are folders ).
DON"T go defaulting to library qgpl or qsys or any other system libraries. PDM and crtlib ( create library ) and crtsrcpf (create source physical file ) come to mind.
After you have a file to work with, then you can use any one of two products, either query or data file utility ( DFU ). Access either one with wrkqry or wrkdfu or strdfu. Again google or use ibm's website search in the iseries area of the online manuals to find books for these two products. They both have wizard-style screens to walk through to setup either a qry or dfu to process your file.
About another 20 minutes of setup, if you know what you're doing.
Both will let you create a module ( qry or dfu ) to work with your previously defined file to perform dumb keypunch entry and simple listing or with qry more sophisticated reports -- like a query to list records with missing data in fields or filtering for anticipated bad data.
Not to mention strsql ( start SQL ). But, that's another question and set of manuals. Yet, if you know one sql, you know them all.
If you need or prefer the pc environment, there is hope.
If access has been configured, if staff access the system with pc terminal emulators like tn5250, then you can also with additional setup of authorizations, use ftp to upload or download data from your file(s). As long as you DO NOT use fancy fields like binary format or packed format for your numeric data -- then ftp will be good enough to translate your data as plain text from the ibm ebcdic to your pc ascii without screwing with your data.
gotcha
Internally within the file, negative numbers have the units position overlaid to indicate negativity so that digit will appear as a letter while positive numbers will be fine.
****fall back plan****
If you don't care to mess with qry and dfu -- then you may be able to use a pc spreadsheet !!
BUT, you still need to do the library and source physical files thing, and the DDS thing and crtpf.
You may use, setup and configure odbc if you don't care much for ftp. With odbc active your file can be downloaded from your library into a Microsoft Excel spreadsheet just fine, even the negative numbers!! And vice versa, upload a spreadsheet to your iseries file. The file's data definition directs how the columns are treated as fields in a record.
Dates and time too yes, you can define a numeric field as a date-time stamp instead of a dumb 6 or 8 digit plain numeric.
If you're using ibm emulators to access your iseries then there is more that can be done from such a pc workstation with it's ibm pc suite for iseries access -- almost drag'n'drop data to or from your file with an equivalent to windows explorer interface.
Have fun. Stay thirsty.