TI really put a lot of effort into making their high volume stuff like that 1 chip. I remember as a kid opening up some TI stuff and quickly being disappointed at how there was literally almost nothing inside of them except the chip/display/keypad like you said.
re the COP410 bonded out, shouldn't be too difficult to determine if it's dumpable or not, just find pin 1 and count bond wires? I've had to do that for NES pirate cart mappers before to figure out the pinout.
sean: did you get that MM77 tested out?
Yeah, the Kosmos Astro astrological calculator is the exact opposite- it's crammed full of components. But it was for a different market.
I just haven't had time to get the Jacks PCB under the scope yet to see what pins are bonded out. I'm not sure if they would bond the pins used for test mode- I guess they might.
I've just got an MM76EL right now. The game runs it with a 9V battery, so I tried dumping it at 9V and got nothing. With the test pin at VSS it looked like it was running normally, but at VDD there was nothing at all, even it I reset it. The chip takes 6.5V to 11V, so I tried 7.5, but that didn't work either. I was probing the RIO port with my Logic16, which isn't really supposed to be used over 6V, although I've used it at 9V before. I didn't want to risk it at 11V, but I gave it a quick try and actually got something. So I'm going to add a level shifter to help make sure I don't burn it up.
The data I got is weird- on power up I got about 1/4 second of pulses on RIO1-RIO8. Zooming in, it's actually 18 groups of pulses. All 8 signals go high for 3.3mS, then there's about 0.5mS of pulses. The 18 groups are similar but not the same. So I'm wondering if I'm in some other test mode, not ROM dump mode. The data sheet says test mode "tests ROM and allows testing of the RAM and instruction logic".
I'm letting most of the pins float, including PIx. Were you driving any other pins when you got your data?