Atlantis wrote:
Ok, I tested each one of those six chips in my computer again, after pulling BE pin up. They still won't work...
Pulling up that BE pin is still progress, though -- it needed to be done. (Understand that we're doing our best to help, and it's not 100% easy to do so remotely.)
I hate to tell you, but there's another pinout difference that could be causing trouble. On the original 6502 (and with older C02's such as Rockwell), pin 1 is Vss aka ground. But modern C02's use pin 1 to output the VPB signal, and trouble can result if the VPB pin is grounded. You may be experiencing this.
Your computer and the NOP test rig don't actually
use the VPB signal, so it's tempting to suppose VPB can be ignored. However, VPB is almost always in the high state, and tying it low can cause trouble. The CPU will
try to pull the pin high, causing the CPU to draw a lot more current from the power supply, and the power supply voltage may droop as a result.
Rather than analyzing VPB or trying to compare power supply voltage drop between two different test rigs, the most direct and unambiguous course of action is to test the six questionable chips in a way that doesn't connect pin 1 to ground. (The other Vss, pin 21, remains connected, so it's not as if we're powering down the chip.)
You
could modify the wiring on your computer to make pin 1 a no-connect, or install a jumper, but what I've done in this situation is to carefully bend pin 1 of the DIP outward about 30 or 45 degrees so that it fails to engage the socket when the chip is inserted.
I hope you find success! IMO it's too soon to declare those six chips defective.
-- Jeff
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In 1988 my 65C02 got six new registers and 44 new full-speed instructions!
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