Well, about that. The number you find is the maximum number of t-states you have to wait until the screen is ready. In reality, the actual number you have to wait varies by quite a bit. For instance, I made a program that tracked how many t-states the screen needed at that moment in time. What I found is that the amount needed was random and was spread out over about 20 t-states. This means that the 70 t-state screen will actually be ready to go in 50 t-states occasionally.

However, the short answer you want is yes, once you find the delay, it will never change.

I had to fix a few little things, but now it should work exactly like you want it to.

.nolist
#include "ti83plus.inc"
#include "dcs7.inc"
.list
_ExecutePrgm .equ 4E7Ch ;feel free to add this to ti83plus.inc
.org progstart ;  doing this everytime will eventually
ld hl, AppVar ;  be a pain when you have a lot
rst 20h
bcall(_ChkFindSym) ;this leaves OP1 intact
jr c, appvarDoesntExist
bcall(_delVarArc)

; jr nc, notOK ;see below VV

ld hl, AppVar
rst 20h
appVarDoesntExist:

ld hl,AppVar-AppVarCode
bcall(_CreateAppVar)
; jr c, notOK ;this throws Err:Memory, not C
inc de ;|
inc de ;|these two are because DE is originally
ld hl, AppVarCode ;  pointing to the size bytes
ld bc,AppVar-AppVarCode
ldir
set 1,(iy+33h)
ret
;notOK:
; ld hl, 0 ;          ^^
; ld (CurCol),hl ;this is a matter of style, but you probably
; ld hl, TextError ; just want to overwrite OFFSCRPT. the reason
; bcall(_PutS) ; for this is in case you run your program twice
; ret ; or there's an OFFSCRPT present you didn't make

AppVarCode:
.relocate $8001
bit 4, (iy + 8)
ret nz ;apd

ld hl, progName
rst 20h
bcall(_ChkFindSym)
ret c ;you probably just forgot this
ld a,b
or a
call nz, UnArchive
bcall(_ExecutePrgm)
call UnArchive
ret
UnArchive:
ld hl, progName
rst 20h
bcall(_Arc_Unarc)
ld hl, progName
rst 20h
ret

progName:
.db protProgObj, "OFFBY1", 0
AppVar:
.db AppVarObj,"OFFSCRPT"

;TextError:
;.db "Error!",0 ;not needed now

.end
END

Every change I made includes a comment.

Go for it.

Another thing though, you need to be sure that OFFBY1 doesn't mess with $8000. If it does, it's going to overwrite your code and crash when it returns. This leaves you with a few options:

• BJUMP to _ExecuteProgram, though you won't be able to rearchive it this way since it completely skips your code when it returns.
• Copy a return code somewhere else, push its address, and BJUMP to _ExecuteProgram
• Or just make sure it's not going to mess with $8000, (that's the easy way)

Make the graphics awesome

Run the game at 20 fps and have a 1 byte memory location called clearance and another called clearanceCounter. Initlialize clearance to 0 and clearanceCounter to 3. At every interrupt, decrease clearanceCounter: if it is nonZero, store it and continue, if it is zero, reset it to 3 and set clearance to 1. In your main code loop, have a routine called waitForClearance. Call this every frame. The code of it should look like this:
waitForClearance:
ld a, (clearance)
or a
jr z, waitForClearance
xor a
ld (clearance), a
ret

What this does is it perfectly syncs your graphics and your grayscale. Every frame is shown for exactly 3 screen updates. This will ensure that the grayscale looks the best it possibly can for moving objects. An added plus is that this system will allow the game to slow down if it starts to lag and get right back to where it was when it stops lagging.

You could also make the frame rate 10, 5, 4, or 2. But... really only 10 and 20 are reasonable.

This is a guide for people for whom TI-Connect is not working, TI-Connect can't find their calculator, TI-Connect is giving strange error messages, TiLP screwed up your TI-connect setup, or TI-Connect is just not working correctly via USB with their 83+, 84+, or their 84+SE / 84+ Silver Edition on Windows XP, Window Vista, or Windows 7.

(Enough key words)


First and foremost, you have to realize that TI-Connect errors mean nothing. What the error says, and what actually went wrong are usually completely different.

Here are the things to try if you get an error message:

• Try clearing RAM (2nd, +, 7, 1, 2)
• Try new batteries (this will fix 90% of cases)
• Check to make sure that your variable name doesn't include illegal characters. For programs, this is anything besides uppercase letters and numbers. (The real name, not the Windows name)
• Check to make sure that you are actually sending the correct file format. .83p -> 83, .8xp -> 83+, 84+ and 84+SE
• Check to make sure that TI-connect is actually recognizing your calculator as the correct calculator
• Make sure that your calculator has enough free memory. If it does, but just barely enough, you might have run into the problem of the memory not being continuous. To solve this, send all your programs to your computer and send them back from biggest to smallest.

On a side note, when it asks you to select a cable, if you are using usb, none of those are the correct choice, so you'll just have to wait for your calculator to show up.

If none of this works, then it's time to have some fun. At any point during the following list you can stop to see if it works, just remember that you'll have to redo all of the previous steps if it doesn't work.

Almost flawless fix method:
1. Open Device Manager (Control Panel>System>Devices>Device Manager)
2. Plug your calculator into a usb port that you know you've plugged it into before.
3. Find your calculator on the Device Manager list, usually under LibUSB devices
4. Right click>Uninstall
5. Repeat 2-4 for any USB port you may have plugged your calculator into.
6. Uninstall TI-Connect through windows
7. If you are on a 32 bit operating system go to C:\WINDOWS\System32\DRIVERS\ and delete libusb0.sys. (It's a driver)
    If you are on a 64 bit operating system, I've never had to delete the drivers, but they are: silvrlnk.sys and tiehdusb.sys.
8. Experimental (though, unlikely to break anything): If you have previously installed TiLP, go to C:\Program Files\Common Files\LPG Shared\drivers\usb\ and delete anything with a .inf extension.
9. Restart your computer
10. Reinstall TI-Connect

And it should work. If it doesn't work, you probably have something else going on since this basically removes all traces of TI-Connect. It will even make TI-Connect work after you've installed TiLP. At this point, you should probably start a topic on this website explaining your problem. (Don't contact TI Cares as they are absolutely no help)

If you are going to be using TI-Connect a lot, you might want to think about buying a Silver Link cable. You can find them at BestBuy for around $15 (at least you used to be able) and they are much more reliable than direct USB. One end of the cable plugs into your usb port, and the other plugs into the I/O port on the calculator.


A final note about why changing your batteries fixes almost 90% of cases. The TI-84 was designed to run on 3.3V, this means when you batteries are low, they are down around 3.4V. But, USB will accept a voltage no lower than 5V. See the problem? If your calculator is running at 4V, it will be perfectly content and tell you that your batteries are fully charged, but when you go to use USB, it's not going to work at all and TI-Connect will give you "Error: Access Denied" or similar.

Rechargeable batteries have also cause a lot of troubles in the past because of the whole 5V issue. Rechargeable batteries don't always charge to the same voltage as standard alkaline and this means that even fully charged batteries may not work.


Update 4/16/2013
I believe (though currently untested) that if you get the error where TI-Connect asks you to locate libusb0.sys, you can solve it by deleting TiLP's .inf files. (Step 8 ) The exact wording on this error is:

The file "libusb0.sys" on TI-84 Plus USB Device Install Disk is needed
Type the path where the file is located, and then click OK.

Also, since they are really hard to find, here is a TI-Connect driver download, with tiehdusb.sys and silvrlink.sys in a zip.

TI-Connect Drivers (32 bit and 64 bit):
TI's Official Page
Omnimaga Mirror (in case TI's page disappears)


DO NOT POST IN THIS THREAD FOR TI-CONNECT HELP, MAKE A NEW ONE INSTEAD

I totally agree with TravisE.

Here's what we need to do. We need to go through ticalc.org and look through the file names. If you see a game that you have played before, (or know the reputation of (Mario)), rate it. It doesn't matter what the rating is, just rate it. Using this method if at least 5 of us do this, by tomorrow, all of the decent games will have a rating.

I honestly believe that our 10 minutes of rating could help >1000 desperate kids find a good game.

Like calc84 said, you need quite a few cycles of delay in 15Mhz mode. To cover all LCDs, you'll probably have to get an upper range of 180 cycles per loop with your average lcd running at 150 cycles.

Your $87 gets divided by 4 and only comes out to 33 cycles. That plus your current 43 only leaves you with 76, and that is nowhere even close to what you need.

Try getting your main loop up somewhere around 120 and setting (2Ah) to $FF. That should give you 183 and will definitely work. From there, you can scale it down to your needs. However, you can't go lower than 123, but, that's ok I guess.

Well if we're going to talk about key sequences, a favorite at my school is: click on desktop, Ctrl+A, Enter, Enter

Here's what happens. Clicking on the desktop gives it focus. Ctrl+A highlights all of the icons, and on school computers, there are a lot of icons. The first enter attempts to open all of the icons, but windows is smarter than that and gives you a warning that you are about to open 30 icons. The second Enter says go for it.

The end result is that the computer will spend at least 10 minutes trying to open all of the programs. Honestly, the best course of action is to turn it off. That, or have fun trying to close the windows as fast as possible