(71b) HP41 module programs in HP71b

[rprosperi]

Here are some notes from the manual on 41 program syntax for the Trans41 ROM. The symbol that resembles ( |- ) is the 41's Alpha Append ([Shift] [K] in Alpha mode), simply called (Alpha Append) in these notes, since it's awkward to insert that symbol here too:

• HP-41 text strings in text lines or following GTO and XEQ should be enclosed in double quotes ("), as they are in HP-41 printer listings. One or more spaces between GTO or XEQ and the quoted string are optional.
Examples:
"ABCDE"
GTO"FRED"
XEQ "GEORGE"

• The (Sigma), (not equals) and (Alpha Append) characters, which are used frequently in HP-41 programs, are not available on the HP-71 keyboard. You can include these characters in your programs either by assigning HP-71 keys to these characters [ (Sigma) is CHR$(28), (not equals) is CHR$(29), and (Alpha Append) is CHR$(127) ], or by substituting standard keyboard characters:

• In conditional functions, substitute # for (not equals).

• In any HP-41 functions containing (Sigma), substitute the letter S for (Sigma). For example, (Sigma Plus) becomes S+.

• In an HP-41 text line, you can substitute the character > for the (Alpha Append) symbol immediately following the first quotes. For example, "(Alpha Append) add this" becomes ">add this".

• HP-41 emulator programs must contain at least one global alpha label so that you can access the program in the HP-41 environment. If you do not include an alpha label, TRANS41 automatically adds a label to the beginning of the translated program. The label uses the name of the intermediate file for its alpha characters.

• Parameters for two-part functions must fall in the ranges:
Registers: 0 through 9999
Numeric local labels: 0 through 9999
Local alpha labels: A through J; a through e
Display formats: 0 through 11
Tones: 0 through 9
Flags (set/clear): 0 through 29
Flags (test): 0 through 55

There are some other obscure subtleties, but the above should help with most program statements.

Regarding separating the source files, each 41 'complete program' (typically starting with a Global Label and ending with an END) should be supplied as a separate text file (either typed in to a Text file on the 71B, or imported via PIL-Box, etc. for TRANS41 to 'compile'. I find the simplest method is to create the source files on the PC and then use ILPer's DOSLINK virtual device is the easiest way, but there are several other options available.