I downloaded the manual for MELSEC software. I hope you can translate to GPPWIN.
The main function is Compare. CMP (FNC 10). This instruction does <, =, and >. I was hoping for =>. To get around this, we can just use > and subtract 1 from all of the constants. (Use = for the last one). If this is confusing, don't worry - it will be clear in the example.
You have 3 thumbwheels in D0 to D2. You need all 3 in one variable. I think SMOV (FNC 13) is used to do this. If you can't, then use SFTL (FNC 35) to shift them in. I hope one of the experts can give an example. For now, I'll assume it's in D3.
1) Use MOV (FNC 12) to copy the number to another variable. We will be comparing and subtracting this variable. Lets use D4 for the new variable.
MOV D3 D4
2) Use CMP (FNC 10) to compare D4 to the value of Y14. It's 100KW. We'll use 99 as a constant. That will make it work the same as >=100.
We're starting high and subtracting down with whole numbers, so this will work. MELSEC uses 3 bits to store the results of the compare. If we tell it we want to use M0, it will use 3 consecutive bits. M0 will be on if the first number is larger. M1 will be on if it's equal. M2 if it's less than. We only care about M0. (but need to be aware that 3 bits are written so we'll use M4 in the next instruction).
CMP K99 D4 M0.
3) Do 2 things if M0 is on. Turn on Y14, and subtract 100 (not 99) from D4.
LD M0, OUT Y14.
LD M0, SUB D4 K100 D4.
I'm assuming we can reuse D4 in the SUB function. In the MELSEC example, they spaced the variables by 2: SUB D10 D12 D14. We're only doing 16 bit, so single spacing should be okay.
I hope you can build it from this. Flow chart:
1) Load thumbwheel in D3.
2) Use your Enter button to move (really a copy) D3 to D4.
3) Compare D4 > K99. If true, M0 will be on.
4) If M0 is on, turn on Y14 and subtract 100 from D4. Write the new number back into D4 (if permitted). SUB D4 K100 D4
5) Compare D4 > K99. If true, M4 will be on.
6) If M4 is on, turn on Y13 and subtract K100 from D4. Write the new number into D4. SUB D4 K100 D4
7) Compare D4 > K99
8) If M7 then Y12, SUB D4 K100 D4
9) Compare D4 > K99
10) If M10 then Y11, SUB D4 K100 D4
11) Compare D4 > K65
12) If M13 then Y10, SUB D4 K66 D4
13) Compare D4 > K65
14) If M17 then Y9, SUB D4 K66 D4
...
For the last one, use the M bit that's equal (the next higher M bit).
No need to do the subtract - after checking for Y1, you're done. Your Enter button will write a new number and start the sequence over. To do the Clear button, move (MOV) a constant 0 (K0) into D4. MOV K0 D4.
If we can't SUB D4 K100 D4, then we'll need to add another instruction and increment the D registers. SUB if M0 is true, MOV D4 D5 if M0 is false. That way, data is always moving to the next register. Subtract does it, but if we don't subtract, then move to keep everything in order.
I've never programmed a Mitsubishi. Wait for the experts to correct any errors first.
