Re: The 6502 Rotate Right Myth
Posted: Fri Jan 12, 2024 6:11 pm
barnacle wrote:
BigDumbDinosaur wrote:
Why does it keep coming up?
Neil (I'll get my coat...)
Surely: why does it keep coming around?
Neil (I'll get my coat...)
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Neil (I'll get my coat...)
Re: The 6502 Rotate Right Myth
Posted: Wed Jan 24, 2024 5:18 am
Quote:
Bil Herd summarizes the situation. “No chip worked the first time,” he states emphatically. “No chip. It took seven or nine revs [revisions], or if someone was real good they would get it in five or six.”
Granted, some changes were made before full commercial production began, resulting in the ARM2. These would have been in light of experience in actually running the hardware, and discovering that a multiply instruction would actually be pretty useful. That doesn't detract from the ARM1 working as designed, fresh out of the oven.
Re: The 6502 Rotate Right Myth
Posted: Wed Jan 31, 2024 5:41 am
Chromatix wrote:
The ARM1 must be the exception that proves the rule. It did work first time - the consternation at bring-up was over a fault in the evaluation board, not the chip!
Granted, some changes were made before full commercial production began, resulting in the ARM2. These would have been in light of experience in actually running the hardware, and discovering that a multiply instruction would actually be pretty useful. That doesn't detract from the ARM1 working as designed, fresh out of the oven.
Granted, some changes were made before full commercial production began, resulting in the ARM2. These would have been in light of experience in actually running the hardware, and discovering that a multiply instruction would actually be pretty useful. That doesn't detract from the ARM1 working as designed, fresh out of the oven.
I always wanted to ask: why did you wire out A0 and A1?
Re: The 6502 Rotate Right Myth
Posted: Fri Feb 02, 2024 4:41 pm
Not sure. I was something like 5 or 6 at the time, so…