Re: CSG 4510 and 4567 and Dmagic reverse engineering

From: Mark McDougall <>
Date: Tue, 27 Jul 2010 03:12:24 +1000
Message-ID: <>

Nate is quite correct, for the most part, but let me add my $0.02 worth...

Old chips were designed by engineers laying out "micro-circuits" much as 
you'd lay out a full printed-circuit board. Hardware-description langauges 
(HDLs) like Verilog weren't used for that back then (despite being invented 
in the 80's).

Newer programmable devices, such as CPLDs, FPGAs and ASICs can be programmed 
using HDLs like Verilog or VHDL. However, just like you can't rip the C 
source from an executable, you can't rip the Verilog source from even these 
programmable devices.

A reasonable number of older devices have been *emulated* in HDLs in recent 
years, mainly by studying the datasheets - often there is enough information 
in the chip data to allow a full emulation without any reverse-engineering 
required. Such devices include 8- and 16-bit CPUs, support chips such as 
sound, PIAs, video etc. Even whole computers - including the C64 & Amiga 500 
- have been emulated in HDLs on a single programmable chip.

For chips that don't have any data, or insufficient data, "decapping" is 
what Nate is describing, and the techniques are only now being refined. 
Usually decapping is required for protected CPUs with hidden ROMs, for 
example, as you'd find in certain arcade games. But it requires expensive 
equipment and a lot of knowledge about how chips are put together - not for 
the home hobbyist.


|              Mark McDougall                | "Electrical Engineers do it
|  <>   |   with less resistance!"

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Received on 2010-07-26 18:00:05

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