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Re: Convert 16x2 chars display to big TFT display

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On 9/21/2021 9:04 PM, olaf wrote:
> Don Y <blockedofcourse@foo.invalid> wrote:
> 
> 
>   >You will likely find there are issues that you've not even considered
>   >that the original software relies on (directly or indirectly).
> 
> Of course, but in these day much is possible.
> 
> https://hackaday.com/2021/09/02/pi-pico-emulates-rom-for-speedy-retro-hacking/
> 
> But it feels strange to do this. :-)

It used to feel strange to only partially decode address spaces for
devices -- so, a single 8b latch would occupy 128KB of address space.

<shrug>  Times change.

By comparison, a ROM is highly predictable.  You don't, for example,
expect a read of address X to take longer when it follows a read of
address A vs. B.  Or, when the datum returned is Q vs. R.

A display controller, OTOH, is a serial machine and the time it
takes to perform an action is typically related to the amount of
"effort" that must be expended.

It's likely that the original code took this into consideration
(implicitly or explicitly).  and, without delving into that code,
it's hard to decide how you can reasonably expect to emulate it
without unexpected consequences in the host.

[E.g., the host may expect to have to wait when it does X.
But, will expect X to have completed before some particular
future time.  If you fail to do so, there's no easy way
of knowing what might "misfire".]

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Thread

Convert 16x2 chars display to big TFT display pozz <pozzugno@gmail.com> - 2021-09-21 12:31 +0200
  Re: Convert 16x2 chars display to big TFT display Reinhardt Behm <rbehm@hushmail.com> - 2021-09-21 13:44 +0000
    Re: Convert 16x2 chars display to big TFT display pozz <pozzugno@gmail.com> - 2021-09-21 16:01 +0200
      Re: Convert 16x2 chars display to big TFT display Reinhardt Behm <rbehm@hushmail.com> - 2021-09-21 15:07 +0000
      Re: Convert 16x2 chars display to big TFT display Stef <me@this.is.invalid> - 2021-09-21 17:09 +0200
        Re: Convert 16x2 chars display to big TFT display pozz <pozzugno@gmail.com> - 2021-09-21 18:48 +0200
  Re: Convert 16x2 chars display to big TFT display Don Y <blockedofcourse@foo.invalid> - 2021-09-21 19:34 -0700
    Re: Convert 16x2 chars display to big TFT display olaf <olaf@criseis.ruhr.de> - 2021-09-22 06:04 +0200
      Re: Convert 16x2 chars display to big TFT display Don Y <blockedofcourse@foo.invalid> - 2021-09-21 21:38 -0700
    Re: Convert 16x2 chars display to big TFT display pozz <pozzugno@gmail.com> - 2021-09-22 08:49 +0200
      Re: Convert 16x2 chars display to big TFT display Don Y <blockedofcourse@foo.invalid> - 2021-09-22 00:58 -0700
      Re: Convert 16x2 chars display to big TFT display Rick C <gnuarm.deletethisbit@gmail.com> - 2021-10-01 21:52 -0700
    Re: Convert 16x2 chars display to big TFT display Rick C <gnuarm.deletethisbit@gmail.com> - 2021-10-01 21:40 -0700
  Re: Convert 16x2 chars display to big TFT display Michael Schwingen <news-1513678000@discworld.dascon.de> - 2021-10-31 14:42 +0000

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