8 Dec
2010
8 Dec
'10
11:37 a.m.
On 2010 Dec 7, at 2:39 AM, Christian Corti wrote:
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.
-tony
On Mon, 6 Dec 2010, Brent Hilpert wrote:
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. The EC-130 (and by extension the 1162) is one I
have wanted to RE and
produce a simulation of, both for the vector display and because the
arithmetic technique used is different than most.
Did you already have a look at the Friden patents?
No. 3523282
No. 3526760
No. 3546676
No. 3725873