Hey there =]

If you don't already know, a delay is needed between writing and reading to the keyboard (using port 1).
The problem is, that the needed time is not accurately known.
Since there seems to be many different opinions about the subject, i decided to code a program to test that up.
The main purpose is to be able to have a better knowledge of the hardware, allowing more optimised low level operations.
Also, maybe we'll have some surprises (ti likes to change hardware pieces).

COMPATIBILITY

TI-83 Plus
TI-83 Plus.fr
TI-83 Plus Silver Edition
TI-84 Plus
TI-84 Pocket.fr
TI-84 Plus Silver Edition
TI-84 Plus Pocket Silver Edition
TI-84 Plus C Silver Edition

All official OS are compatible, as long as you TURN OFF MATHPRINT.

INSTRUCTIONS

Simply execute from the homescreen and follow instructions.
Important : When pressing the 0 key, you must HOLD it until the end of the test.

DOWNLOAD

black & white models : http://www.omnimaga.org/index.php?action=dlattach;topic=16102.0;attach=15043
TI-84 Plus C Silver Edition : http://www.omnimaga.org/index.php?action=dlattach;topic=16102.0;attach=15044

RESULTS

The displayed value(s) are the needed delays (in cycles) for each CPU speed mode (order : 0,1,2,3).
A question mark specifies an unknown delay.
Please don't forget to specify the model and serial number end (at the back of your calc, in the form X-XXXXX).


Code:


THANKS IN ADVANCE FOR YOUR PARTICIPATION =]

I'm using a TI-84+ SE with OS 2.55MP, s#: P-04100
Result: 4 20 20 20

Also did it with Wabbitemu, using my TI-84+ SE ROM: Results: 0 0 0 0

Thx willwac =]
Your results have been added to the list.

TI-83+, OS 1.19, serial suffix S-0504E

Result: 0

What is the purpose of the serial xuffex?

It determines production location and date.

How do you know when it was made? Where is the database?

http://datamath.org/Datecodes.htm

These calcs use the "Far East" date codes. So, my 83+ was made by Inventec in Shanghai, in May of 2004. Your 84+SE was made by Inventec in Pudong, in April of 2010.

That result is very unexpected...
Are you sure you pressed and holded the [0] key ?

*****

For now, the longest delays (old models mainly) seem to stick to 6,29,29,29.
More results would be appreciated, especially with old models.

Regarding the CSE, only one model was tested so far.
Those very long delays are probably due to a slowest keyboard but again, more results are needed to be objective...

I turned the calculator on, went to PRGM, selected KBDELAY and hit enter twice to launch it, then HELD 0 for 30 seconds. (I was expecting more than just a 0 myself, so...)

0 is what came up as soon as it registered that I was pressing 0.

Edit: Horrible quality video: http://www.youtube.com/watch?v=s-dnNnIyVhk

Went ahead and cut off the end of the video, that shows enough now.

No need to hold it 30 seconds.
In fact, you need to hold it until it says "[CLEAR] > exit".

I guess your model has either a very fast keyboard, or a very slow CPU, or both.

Okay then, i'll add that result soon.
Thx a lot !

I have 2:
83 Plus SE (overclocked)(I-0501):
KB delay:
4, 23, 30, 37
clock speed(Mhz):
5.4, 14.2, 17.3, 20.4
84Plus SE (P-04100):
delay:
4, 17, 17, 17

Thx fortytwo =].
I'll add these results as soon as possible.

Sorry to bump such an old topic, but i had to keep cemetech users up to date about some new discoveries.
Everything is in there : http://www.omnimaga.org/asm-language/port-1-stuff/