Hp-19Bii ROM dump -- is it possible?

[Christoph Giesselink]

Some of the ROM images haven't been extracted. About 10 years ago some at HP had been interested into an emulator for some calculator models. To make them I got access to some images. But it's a pity that several other images got lost over the years.

I only know a theoretical method to extract the images from real calculators. Only on the 18C you have direct access to the Saturn bus. Executing a self test should show the ROM content on the bus. With the 1LU7 Bert, the 1LR2 Lewis and 1LR3 Sacajawea CPU's the situation is much more difficult, in all chips the Saturn bus is only inside. The technical documention tells that's a special "debug mode" could be activated over some pins at CPU startup. In this "debug mode" the data on the Saturn bus should be visible on some other pins. All calculators have a self test with a complete ROM check, so the ROM image data should be visible on the bus. But these technical documents tell nothing about the pin layout, so it's a theoretical method only.