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Messages - DrDnar
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61
« on: October 25, 2013, 08:27:08 pm »
I don't believe so, but honestly, it's been so long that I can't recall. You'll just have to try it.
62
« on: October 03, 2013, 10:51:34 pm »
Hi there! So there has been some progress. A new kernel can be downloaded from here. I have switched to the MicrOS LCD initialization code. Unfortunately, this does not seem to help. Does anyone know if DrDnar has successfully run MicrOS as an operating system, instead of an app? The LCD has already been initialized by TIOS by the time an app gets run.
The current behavior is to start up properly (and you can control the backlight), but attempting to initialize the color screen and clear it to solid grey does not work. There is no visible change in the LCD. The MicrOS LCD init code uses the crystals and HALT for timing if I remember correctly; check to make sure you're duplicating the delays properly, because the datasheet on the driver clearly specifies them as necessary. At any rate, it has been tested, because turning the calculator off and on works. You have to completely uninitialize the LCD when you turn off the calculator or else the driver continues to consume current. Not as much as the backlight for sure, but still a lot more than the B&W LCD would consume because it's a very different type of LCD.
63
« on: October 02, 2013, 09:55:16 pm »
It seems that the new TI-83 Plus.fr USB in France (which use the TI-84+SE hardware) have their Boot Code write protected: EpicFail and Flashy don't work anymore.
I can write a program to test this directly. It's hardly surprising, considering they did the same thing on the TI-84+CSE.
64
« on: October 02, 2013, 09:08:26 pm »
Hi there! I need some help getting support for the TI-84+ Color Silver Edition in KnightOS. I started working on it a few weeks ago, and here's the current status of the color project:
- The screen is not initialized correctly
Everything works great, except for the color LCD. I cannot get it to start up correctly.
Just use the MicrOS screen init code, from the files lcd.asm and lcd_data.asm. It basically just does the same port writes as the boot code does, but using a script. You can strip out half the script features for a smaller init routine. Oh, by the way, there might still be a minor bug in the GPIO initialization (port 39h). It should be initialized to E0h, not F0h. Also, WARNING WARNING DANGER DANGER: The calculator does not seem to have a hardware low-battery shut-off. Your software must check the battery regularly and power-off if the battery is bad. I've been doing some research on this. I have some code for testing the battery level, but I haven't figured out exactly how to check the external power and charging status. Bit 4 of 3A seems to indicate if the battery is actively charging, but if you're plugged in and drawing power from USB without charging, it won't show that. I've also actually seen some behavior that suggests the battery will not charge is the USB controller is in the wrong state.
65
« on: September 24, 2013, 01:22:39 pm »
Update: Help now has topics, text preview has word wrap, and it now runs on .NET 3.5 Client Profile, so it should work on Vista out-of-the-box.
66
« on: September 07, 2013, 11:50:55 pm »
As far as I know, there's no downgrade prevention code in the new boot code. If there is, it would have to be certificate-based, which we can modify at will once flash is unlocked. Brandon has a library of flash unlock exploits ready and waiting, so it should never be an issue.
67
« on: September 07, 2013, 11:06:54 pm »
Oh I didn't know they fixed it on the CSE. Does it means that the CSE might never ever be downgradeable?
Downgradeable? There's nothing to downgrade to. Besides, there are other methods of uploading a custom OS.
68
« on: September 07, 2013, 10:01:23 pm »
I think the only way for TI to prevent any such hacking would be to remove the Asm command and Flash APP support on new models, but since they're popular due to all the programs for them, I doubt that TI would be able to afford to do that, not to mention they might have left ASM support intact on those calcs just so that the TI-Nspire lockdown pills are easier to swallow for us.
The reason that we can defeat the 2048-bit key on the TI-84+/SE line is that the boot sector is not properly protected. TI fixed that with the TI-84+CSE, and there's no reason they can't apply that fix to the TI-84+/SE, other than that it would require them to make a few minor changes to the manufacturing process. (Specifically, the TI-83+ originally protected the boot sector by having the factory lock the boot sector using a locking feature the flash chip itself has, which can only be overridden by apply +12 V to the right pin. Later, they decided that they wanted to save a few pennies per unit by rolling their protection circuit into the ASIC, instead of using the protection capabilities that the flash chip itself has. This system works fine on the TI-83+, but the TI-84+ ASIC system is easily circumvented once flash is unlocked. (We simply tell the ASIC that it has a 4 MB or 8 MB flash chip, instead of 1 or 2 MB. Thus, it stops protecting the boot sector because it doesn't know it's a boot sector anymore.) After we discovered this, TI decided to return to the flash chip's locking system for the TI-84+CSE.) I'm not saying they could stop us from running custom code. But I am saying that they can stop us from patching the boot sector(s).
69
« on: September 03, 2013, 06:50:17 am »
I figure that some compromises will be necessary for Mario and platformers in general, but I suspect you can make a game with fast enough performance to be quite enjoyable.
70
« on: August 23, 2013, 11:24:42 pm »
New update! I've added support for importing BDF fonts and including a package of the 77 BDF fonts from the RockBox project. I'm publishing source code, too, so you can add your own exporters if you want. You'll need 7zip to extract the BDF package because compressing it with ZIP resulted in a file too big to upload.
71
« on: August 10, 2013, 06:36:26 pm »
IIRC 20Mhz is about the max clock speed for a z80. The TI-84 +CSE is at 15.
Actually, according to Michael_V (who was before your time), TI's engineers believed the top speed of the TI-83+SE ASIC was about 25 MHz. You may have heard some community members throwing around 20 and 25 MHz numbers. Those numbers come from Michael_V, who had contacts in TI's engineering division. Since the TI-83+SE was basically a beta of the TI-84+/C/SE ASICs, that most likely applies to those, too.
72
« on: August 09, 2013, 03:55:23 pm »
Bug : The current version has "Magnificatio", missing an 'n' at the end.
Where? Can you show me a screen shot? It may simply be that the 'n' got cut off because your computer is using a slightly larger font than mine. I like that I can use the arrows to move the cursor and 'enter' to toggle the bit 
Space works too, and there are keyboard shortcuts for navigating (Ctrl+W, Ctrl+P, Ctrl+N, Ctrl+F). The first font editor I made was keyboard-only. I've found that there are strengths and weaknesses to the keyboard and mouse, so I decided to implement both. Also, this project isn't dead. I'm working on adding support for importing BDF fonts. I'll release the source soon.
73
« on: August 08, 2013, 11:18:26 am »
The LCDs are manufactured for TI by a third-party. There are many factories capable of manufacturing compatible LCDs, and TI simply chooses whichever offers the best price. There is no way for you to detect, in software, the properties of the LCD. The same thing is true for the LCD controller module. You just have to ask the end-user.
74
« on: July 25, 2013, 11:24:15 pm »
As far as I know, the only documentation on how apps provide support for the ExecLib is in the USB8X source. BrandonW may or may not be able to shed some light on the issue. It may prove more informative to disassemble the relevant code in the OS yourself. (And don't forget to document your findings on the Wiki!)
75
« on: July 19, 2013, 11:22:49 am »
The TI-83+ pictured above has a discrete Z80, so yes, you can tap directly into the Z80 bus. In fact, somebody else did that in the early 2000s, though I don't recall the Website it's documented on. The TI-84+/C/SE does indeed have a keyboard matrix. It should have an 8+7+1 layout: 8 rows, 7 columns, and the ON key. However, the keyboard pins are protected by transistors, making them unsuitable for GPIO. There is indeed an external data bus and address bus. The address bus on the TI-83+SE was 24 bits: 23 address bits, plus a bit selecting RAM or flash. I don't know if the TI-84+/C/SE ASICs still have that RAM/flash select bit, but they all probably nevertheless assert the address onto the bus for RAM read/write. The LCD driver almost certainly shares the same data pins. Mysterious sources indicate that the TI-84+/C/SE TA3 ASIC also feature four external chip select pins for future expansion. The Z80 can address them by reading/writing ports 3C-3F. As far as I know, they are unused. On the TI-84+CSE, they read non-zero, but the value never changes, so it may be garbage. Unfortunately, nobody has pinout information. However, some high-resolution photographs I took of my revision A TI-84+SE and my shiny new TI-84+CSE may be useful to you. As far as I can tell, the right side has keyboard matrix pins, the top has USB stuff, the left has the data/address bus pins, and the bottom may contain more, plus miscellaneous stuff like the CPU clock frequency and the 32768 Hz crystal.
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