Reading keyboard upon reset [message #352890] |
Tue, 19 September 2017 12:03 |
anthonypaulo
Messages: 531 Registered: September 2013
Karma: 0
|
Senior Member |
|
|
Was reading blondi hacks where she was working on her accelerator and she said she was unable to read the keyboard upon reset and I'm wondering if you guys can illuminate why the keyboard strobe would not provide key press information at this early juncture.
|
|
|
Re: Reading keyboard upon reset [message #352891 is a reply to message #352890] |
Tue, 19 September 2017 12:28 |
|
Originally posted by: Jorge
On Tuesday, September 19, 2017 at 6:03:10 PM UTC+2, Anthony Ortiz wrote:
> Was reading blondi hacks where she was working on her accelerator and she said she was unable to read the keyboard upon reset and I'm wondering if you guys can illuminate why the keyboard strobe would not provide key press information at this early juncture.
Was that on a IIe ?
--
Jorge.
|
|
|
|
Re: Reading keyboard upon reset [message #352894 is a reply to message #352893] |
Tue, 19 September 2017 13:55 |
|
Originally posted by: Jorge
On Tuesday, September 19, 2017 at 7:14:13 PM UTC+2, Anthony Ortiz wrote:
> She was using a IIc.
Ohhh, well... but I'm going to say it anyway :-)
"In a IIe you never know what's going to happen next after you hit reset"
--
Jorge.
|
|
|
Re: Reading keyboard upon reset [message #352895 is a reply to message #352890] |
Tue, 19 September 2017 14:53 |
Michael J. Mahon
Messages: 1767 Registered: October 2012
Karma: 0
|
Senior Member |
|
|
Anthony Ortiz <anthonypaulo@gmail.com> wrote:
> Was reading blondi hacks where she was working on her accelerator and she
> said she was unable to read the keyboard upon reset and I'm wondering if
> you guys can illuminate why the keyboard strobe would not provide key
> press information at this early juncture.
>
I'd expect reset to clear the keyboard latch until some key is pressed.
--
-michael - NadaNet 3.1 and AppleCrate II: http://michaeljmahon.com
|
|
|
Re: Reading keyboard upon reset [message #352897 is a reply to message #352895] |
Tue, 19 September 2017 16:13 |
anthonypaulo
Messages: 531 Registered: September 2013
Karma: 0
|
Senior Member |
|
|
Quoted from
http://quinndunki.com/blondihacks/?p=2546
"The last piece of the puzzle was how to get the accelerator to switch modes when I wanted it. I didn’t just want to disable it completely, though I now had the tools to do so. Ideally, I wanted to reverse the meaning of the Esc key. In other words, the machine would boot into 1MHz, unless you hold down Esc, in which case it would boot into 4MHz. This is the opposite of how it currently works. I figured I could simply check the Esc myself after the accelerator had done its initialization, and disable the accelerator if needed (Esc up), or leave it alone (Esc down). This turned out not to work, however. It seems that we’re so early in the boot process that the keyboard buffer isn’t working yet, so normal keys can’t be checked from software. This might be part of why the CGGA does this check directly in hardware, and why I didn’t find the ROM code that I expected to for this."
Not sure why she's unable to read the keyboard when the accelerator can do it.
|
|
|
Re: Reading keyboard upon reset [message #352900 is a reply to message #352897] |
Tue, 19 September 2017 20:25 |
|
Originally posted by: R.Kiefer.SPAEM
Anthony Ortiz wrote:
> Not sure why she's unable to read the keyboard when the accelerator can do
> it.
How long does the keyboard controller need for his internal boot
process? This chip is incredible slow compared to the main cpu. The
frequency is 50kHz.
Fundamental question: is the keyboard encoder software/microcode based?
Why did Apple software guys take the apple keys (game port! not keyboard
encoded) to give the user the choice to start the hardware test (in the
IIe)?
Other details: the keyboard encoder 3600PRO doesn't use the /Reset
signal from the mainboard. This chip generates an own internal Reset
after powering up. Once(!) after power up. Also the 3600PRO needs +5V
and(!) -12V. If the power supply won't be able in generating stable -12V
the 3600PRO won't start reliable.
- Ralf
|
|
|
Re: Reading keyboard upon reset [message #352902 is a reply to message #352890] |
Tue, 19 September 2017 21:48 |
|
Originally posted by: roger.shimada
On Tuesday, September 19, 2017 at 11:03:10 AM UTC-5, Anthony Ortiz wrote:
> Was reading blondi hacks where she was working on her accelerator and she said she was unable to read the keyboard upon reset and I'm wondering if you guys can illuminate why the keyboard strobe would not provide key press information at this early juncture.
This is one of the numerous problems with the //c+ CGGA (accelerator) code.
On a RESET, the CGGA clears the keyboard strobe - unless the Escape key has been pressed!
Still tempted to write "The Horrors of the //c+ Accelerator Code" even if much of it is already covered by https://gist.github.com/mgcaret/022bd0bb3ee71f28429972523556 416e
|
|
|
Re: Reading keyboard upon reset [message #352908 is a reply to message #352902] |
Tue, 19 September 2017 23:13 |
Michael J. Mahon
Messages: 1767 Registered: October 2012
Karma: 0
|
Senior Member |
|
|
<roger.shimada@gmail.com> wrote:
> On Tuesday, September 19, 2017 at 11:03:10 AM UTC-5, Anthony Ortiz wrote:
>> Was reading blondi hacks where she was working on her accelerator and
>> she said she was unable to read the keyboard upon reset and I'm
>> wondering if you guys can illuminate why the keyboard strobe would not
>> provide key press information at this early juncture.
>
> This is one of the numerous problems with the //c+ CGGA (accelerator) code.
>
> On a RESET, the CGGA clears the keyboard strobe - unless the Escape key has been pressed!
>
> Still tempted to write "The Horrors of the //c+ Accelerator Code" even if
> much of it is already covered by
> https://gist.github.com/mgcaret/022bd0bb3ee71f28429972523556 416e
>
Yes, the code looks like a real rush job...
--
-michael - NadaNet 3.1 and AppleCrate II: http://michaeljmahon.com
|
|
|
Re: Reading keyboard upon reset [message #352909 is a reply to message #352900] |
Tue, 19 September 2017 23:13 |
Michael J. Mahon
Messages: 1767 Registered: October 2012
Karma: 0
|
Senior Member |
|
|
Ralf Kiefer <R.Kiefer.SPAEM@gmx.de> wrote:
> Anthony Ortiz wrote:
>
>> Not sure why she's unable to read the keyboard when the accelerator can do
>> it.
>
> How long does the keyboard controller need for his internal boot
> process? This chip is incredible slow compared to the main cpu. The
> frequency is 50kHz.
>
> Fundamental question: is the keyboard encoder software/microcode based?
>
> Why did Apple software guys take the apple keys (game port! not keyboard
> encoded) to give the user the choice to start the hardware test (in the
> IIe)?
>
> Other details: the keyboard encoder 3600PRO doesn't use the /Reset
> signal from the mainboard. This chip generates an own internal Reset
> after powering up. Once(!) after power up. Also the 3600PRO needs +5V
> and(!) -12V. If the power supply won't be able in generating stable -12V
> the 3600PRO won't start reliable.
>
> - Ralf
Good point.
I've always guessed that it wasn't the initial keypress of ESC that was
detected, but the auto-repeat ESC that comes after...
The encoder undoubtedly takes many milliseconds to reset, as it takes
several milliseconds to denounce a key press.
I expect that accelerators sensing the ESC key wait (during their
initialization) for a good fraction of a second before reading the
keyboard.
BTW, the 3600PRO is a (slow) hardware state machine, not a microprocessor.
At the time, microprocessors used too much silicon for an inexpensive
keyboard encoder. Wow, -12v! Must be an old process, too!
--
-michael - NadaNet 3.1 and AppleCrate II: http://michaeljmahon.com
|
|
|
|