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Were there calculators in the 70s?
Up to the early 1970s calculators were, in general, specialised and expensive machines. They were sold through specialist dealers, who could provide back up such as training and servicing, but who also had a high mark up on the price.
What happened to HP calculators?
While HP calculators are still being sold after the death of HP’s calculator division, they are no longer designed in-house but instead come from an outsourced OEM/ODM.
Can you remove something from resin?
You can use isopropyl alcohol, also known as isopropanol, to remove uncured epoxy resin. Since liquid resin is not yet that hard, removing epoxy with acetone or vinegar also works well.
How is the Blob used to protect the IC?
The blob is an epoxy resin to protect the IC with the bonding mechanically; the bonding wires are very thin (as thin as 10 μ m for gold wire) and therefore extremely fragile. Another form of protection it offers is reverse engineering protection.
What’s the black blob on a PCB called?
The black blob is the only non-basic piece of circuitry present, along with an op-amp (top) and a single bipolar junction transistor. It’s called chip-on-board. The die is glued to the PCB and wires are bonded from it to pads. The Pulsonix PCB software I use has it as an optional extra.
Are there any non basic components in the black blob?
The black blob is the only non-basic piece of circuitry present, along with an op-amp (top) and a single bipolar junction transistor. \\$\\begingroup\\$ @Joby – I’ve never tried it, but I imagined that the epoxy is a different sort of component from the plastic cases. Now I need to get myself some acid and try it out….
What kind of chip was used in Busicom desk top calculator?
Intel completes the task with a single microprocessor chip, the 4004, which is used by Busicom for a desk-top electronic calculator. Intel eventually buys back the rights to the 4004 for use in other devices. The modern-day Pentium IC links back to this early calculator chip.