I have finally reached the point where I only have two problems. Well, I also need to optimize. Anyway, the first problem: the calculator doesn't turn off, at least not in jsTIfied. The second problem: the calculator always acts as though I typed in the wrong password.

Here is my code. What is wrong with it?

Code:

The problem could be with the way you use the registers. The registers are really volatile and are very likely to change value when you run another routine (in your own code or as a bcall). Don't expect that the registers will be preserved unless you preserve them yourself.

Also, you're using the wrong key codes. Those are for _GetKey, _GetCSC codes are prefixed with "sk", eg "skUp", "skRight", etc. Add an "s" in front of all those keys and you should be good to go.

EDIT: Also, try setting apdRunning in apdFlags:
Code:

Thank you so much! I have now reached the final stages of the program creation, if not the end. Interestingly, this is the first time I have ever, in my entire life (and I know many programming languages), completed a major programming project.

(Your suggestion about setting the apdRunning flag worked, as you have probably inferred.)

One last thing. Can anybody find any optimizations, major or minor, to make to this program?

Here's what i came up with:
Code:


EDIT: Also, what about adding in an option to change the password? All you need to do is read the values with _GetCSC and overwrite them in Password. DoorsCS will take care of writing it back into your program (program writeback) for you.

Anyway, congratulations! Now your calculator is secure!

One last question. I need to display my email address in small font (_VPutS), and I want to color it navy blue. I already know how to color text with normal (large) font, and I have all the code to color small font except: what is the address of the flag that enables colored small font? WikiTI says that the flag is called penDrawColor, and it is one of the bits at (iy+$14). To the extent of my knowledge, this does not exist in my ti84pcse.inc (like the equivalent flag for large font). So, which bit of (iy+$14) is penDrawColor, or is it even at (iy+$14)?

If you're using _VPutS, text is colored already. You just need to set the color using drawFGcolor (or at least that's what I call it in Doors CSE's source, and it looks like the WikiTI include file calls it the same thing):
Code:

Can't you just do

Code:

? Or is this just so you can change text color with the same command?

You can't load an immediate value into an immediate memory address in z80 assembly. BLACK is a numeric constant ($0000, incidentally, as it's a 16-bit 5-6-5 RGB color), and drawFGColor is a 16-bit memory address.

Nah, because the z80 doesn't let you store things like that into memory. You need to load it into a register pair first, and then store it.

Thanks! I get it now

Thanks everyone! I shall use this program for my personal use, and create another version without all the "This calculator belongs to..." stuff (my personal information), and in which users can change their password, and which I shall post in the Archives.

Great! Now as the first successful program is done, do you have any further plans? Nice work on getting this done and sticking with it; z80 is certainly not an easy language to get used to. Keep it up!

"One must not count his or her chickens before they hatch."

I have another problem. I can't get the right coordinates for _VPutS. What would be the small font coordinates (the value of penRow) for the beginning of row 3 of large font? When I experiment with coordinates, the small font often doesn't even show up at all, which causes other side effects later in the program.

In answer to MateoConLechuga's question, my immediate next plan for Z80 is the fake reset program. That, of course, will not be something that I will publish in the Archives. After that, I will do what I said: publish a modified version of this program. After that...I really don't know. I shall probably begin working on a chess app for the CSE. Actually, for the CE: by the time I am done with the fake reset program, the TI-84 Plus CE will have come out, and I will have bought it. An eZ80! So awesome!
I also plan to generally help the Z80 community by adding documentation for the CSE (flags, RAM, bcalls, etc.) on WikiTI. There is an enormous lack of such documentation, as I have often found to my dismay.
I assumed that you were asking about Z80 Assembly and compatible languages. Other than that, I shall learn Python and Java, the two most useful programming languages that one can learn. I don't have any specific project plans for those high-level languages.

Just to clarify, penRow operates on a pixel basis. Setting penRow to 0 is the very top row of pixels, setting it to 4 is the 5th row of pixels. Not the fifth row of text, the fifth row of pixels on the screen (4 pixels from the top). On the 83+ you generally add 6 to move down a row of text. How are you loading your coordinates? penCol comes before penRow in memory, so if you want to load both at the same time you have to load it into penCol (unlike big text where you load it into curRow). Eg.:

Code:

I figured out the coordinates a few seconds before you (chickendude) posted. However, I still thank you, because I didn't realize that you could load to curCol and curRow at the same time.
However, this isn't working for me. I suspect that it might have something to do with little-endianness.
Here is the unoptimized code that works:

Code:

How would I simplify that into two instructions?

It's because you are overwritting one with another. You could do:

Code:


EDIT: Of course, say you have an X & Y point in decimal. You can load them by doing:

Code:


Hope this helps!

There's a problem with that code, too. You are loading two bytes into a one-byte address.

Code:


EDIT: Adding onto to Mateo's post, you could also do "ld bc,(Y<<8)+X".

Thanks all. But then why isn't

Code:

working? Isn't that what you said; doesn't it follow the 256*Y+X pattern?

I dunno, you aren't overwriting it somewhere else?

Perhaps there is something else in the code. Can you post some more?

Also is there anything on screen at all? Does the program crash etc?