First thing you need is a hacking program. I use Hex Workshop, which you can download at the Downloads section. Open Hex Workshop, and you'll see columns of numbers in Hexidecimal format. The numbers on the left show about where you are at. All of the variable stuff you can edit in Rygar is in the row labeled 20C0. Find that row, and click on a column. In the lower right, you should see something saying Offset: XXXXXXX, and the numbers it shows you are exactly where you are. So, to edit Tone for example, simply click on the part where it'll say 20C6, and enter in your new value in Hexidecimal format
If you don't know Hexidecimal, don't feel bad. I don't really either. It's a number system based on 16, unlike ours, which is based on 10. So Hexidecimal uses the letters A-F to fill in the missing parts. So after 9, it's A, then B, and so on. It gets confusing...
However, included in Hex Workshop is a nifty calculator that can convert normal numbers into Hexidecimal and vice versa.
It can be confusing, but really it's not that hard to do. If you have any further questions, ask me.
Max HP Location: 20CA
Since the HP in Rygar isn't in numerical value, but instead in "heart containers", you can't simply enter in a number and have Rygar have that HP. Below is a chart showing you what will happen if you enter in different values. The numbers below are in HEXIDECIMAL format.
The max number of life Rygar can have is 12, but you can give him more than that. If Rygar's maximum HP is above 12, the game slows down dramatically, and Rygar's life meter is screwed up.
Tone & Last
Tone Location: 20C6-20C7
The maximum value you can give Rygar for either Tone or last is 65535 (FFFF in Hexidecimal). If Rygar has this amount of Tone or Last, and he gets another Tone or Last point, he goes back to zero.
Mind Point Location: 20C3
This one is pretty self-explanatory. Normally Rygar can only hold 7 Mind Points, but you can give him up to 255 (FF in hexadecimal).
This one is more difficult. First you must picture Rygar's items as in two rows. A top row and a bottom row. The top row consists of the grappling hook, the pulley and the crossbow. The bottom row consists of not only the coat of arms and the armor, but also the "usable items", the Life Potion and the Pegasus Flute
The way to hack yourself the items you want is tricky. By entering in different values, you get different combinations of items in your inventory. There doesn't seem to be any pattern to it, so the easiest way to show you how to do this, is by making tables
Top Row Location: 20C0
Bottom Row Location: 20C1
ONE MORE THING: The "hundreds place" in the code is irrelevant. No matter what it is, the effect doesn't change, so I'm simply going to put an 'X' in its place. THIS X IS ONLY A VARIABLE. Put whatever the hell you want in for the X. It doesn't matter.
Using these two tables, you will be able to give yourself any combination of items Rygar can obtain. For example, if you want Rygar to have a Life Potion, the Grappling Hook, and the Wind Pulley right off the bat, enter CX (or DX) at 20C0, and 1x at 20C1