Pioneer Proof of concept

[brouhaha]

(01-19-2024 05:28 PM)HP-Collection Wrote:  Unfortunately, the device is not executable.

One reason for this is that the Saturn chip is not present. Part of the frame for the TAB (Tape Automated Bonding) is present, but the die, and possible a TAB frame. appear to have been removed. See this photo of the HP 42S board by Takayuki HOSODA for comparison:

http://www.finetune.co.jp/~lyuka/interes...p42s-9.jpg

The black square in the center of the frame is the die. The location for the die in your prototype is obviously empty, and it appears to be irregular in a way suggesting that a die may have originally been present, but later removed.

Your prototype appears to have used a somewhat different variation of assembling the TAB chip onto the main PCB. It's possible that it didn't use the plastic frame, but it definitely needed the die!

The NEC uPD4464G-15L is an 8K byte static RAM, equivalent to that in the HP 42S.

The key legends suggest that this was built VERY early in the development of the Pioneer platform. It was apparently a very basic scientific calculator, not closely matching any model that HP actually shipped, but it would have been quite acceptable as a demonstration of a working hardware platform.