Eprom Emulation

[David A. Cooley]

At 07:06 PM 4/6/99 -0700, you wrote:
>This is a great idea!  You could use 2 SRAMs (or eeproms), run the ECM
>off one, then load data in to the other.  It would be hard to do this
>with only one sram chip, because the data lines can't run to 2
>processors at once...
>
>There would have to be some sorta latches to switch the data lines
>between processors...  hmm...

Use several CMOS SPDT switches on each SRAM to the data/address bus (common
to SRAM, NC to data bus for emulator, NO to EPROM socket) and use an
inverter between the toggle lines of the SRAM1 and SRAM2 switches... when
one is on the PCM bus the other is on the EMULATOR bus and vice-versa...
all lines switch simultaneously, so there should be no problems when you
switch programs...

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           David Cooley N5XMT           Internet: N5XMT at bellsouth.net
     Packet: N5XMT at KQ4LO.#INT.NC.USA.NA   T.A.P.R. Member #7068
       I am Pentium of Borg...division is futile...you will be approximated.
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