9 Dec
2010
9 Dec
'10
2:06 a.m.
On Wed, 8 Dec 2010, Tony Duell wrote:
Sure, but the patents help identify signal names and understand the
priciples of the machine. You can't easilly find out how a machine works
by just looking at the flip-flop or some random logic. We had to repair
some Friden 132 boards just a few weeks ago, the block diagrams and
descriptions in the patents were quite helpful.
Christian
No, I
haven't. The objective is to make a precise gate-level simulation
of the calculator, both for understanding and which can be used to
track down faults in a broken instance of the real thing. Patents
generally don't provide the level of accuracy for that objective, so it
generally doesn't occur to me to look to patents for these purposes.
As n aside, some of the HP desktop calcualtor patents are very detailed,
and include sechematics, commented firmware source, extension ROM
sources, and so on. But as you imply, there are often suble differences
between the machien described i nthe patent and the actual prodcution
model. I regard these patents as a very useful resource and well worth
reading, but you need to check against an actual machine.