Re: 27cxxx eprom switcher

In article <070220072117514671%artie.m@xxxxxxxxxxxxxxx>,
artie.m@xxxxxxxxxxxxxxx says...
In article <45ca3720$0$83734$c30e37c6@xxxxxxxxxxxxxxxxxxxxxxxxxxx>,
mark krawczuk <krawczuk65@xxxxxxxxxxx> wrote:

hi , can anyone point me in the right direction for a eprom switcher
schematic ?

this is what i want to do :

i have a engine ecu which contains a 27c128 eprom , i want to be able to
switch between 2 .bin files (maps) while the engine is running i.e on
the fly . i presume i will have to use a 27c256 eprom .?

any help appreciated.

mark k




Ooh, sounds like fun...

You should be able to just switch the top address bit on a c256 to
select which c128 image you're feeding to the ecu.

Ignore those worrywarts -- go for it. What's the worst that can
happen, eh?

Have someone taking pictures, video -- from a distance.


I did something very similar for a game that someone wanted to swap a
lookup table during runtime. It has been a LONGGGGG time ago, but what
I did was to use a latch to change the upper address line (swap banks)
only during the rising edge of /CS. That way I knew the CPU was doing
something else and, in this case, just swapping the lookup table didn't
blow anything up.

Jim
.

Relevant Pages

  • Re: 27cxxx eprom switcher
    ... mark krawczuk wrote: ... i have a engine ecu which contains a 27c128 eprom, i want to be able to ... switch between 2 .bin files (maps) while the engine is running i.e on ...
    (sci.electronics.design)
  • Re: 27cxxx eprom switcher
    ... mark krawczuk wrote: ... i have a engine ecu which contains a 27c128 eprom, i want to be able to ... video -- from a distance. ...
    (sci.electronics.design)
  • Re: 27cxxx eprom switcher
    ... i have a engine ecu which contains a 27c128 eprom, i want to be able to ... OE lines (you'd have to peal of the bottom ones OE line from the board), ... gate these with the board signal. ...
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