Re: 747 Rom Emulator / design

[Ludis Langens <ludis@cruzers.com>]

steve ravet wrote:
> 
> As far as DP ram, IDT makes them and they're really no more complicated
> than SRAM.  There are two address busses, two data busses, one of each
> to the EPROM socket and PIC.

According to discussion in several Usenet electronics groups, recent
FPGA's contain RAM that can function as dual port SRAM.  These FPGA's
are logic devices that are configured by loading a configuration from an
external serial PROM into SRAM in the FPGA.  Portions of this
configuration SRAM can be used as user RAM instead.

One of these FPGA chips could be used to make a "single chip" emulator
for a '747.  I don't know how much DPRAM they can contain, but it should
be enough for the 4Kbytes of a '747.  The rest of the FPGA could contain
hardwired logic for reading/writing the DPRAM via a serial link.

-- 
Ludis Langens                               ludis (at) cruzers (dot) com
Mac, Fiero, & engine controller goodies:  http://www.cruzers.com/~ludis/

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