Why, 23! However, since you are counting Pin 0, it would actually be 24.
The new chip will also only cost $5, since it's only a little more then half of the original prop. :-)
Actually I would rather it be a P8X64B :smilewinkgrin:
A P16X64C would be even better :idea:
I recall buying faulty TTL chips cheap ($1 ea) in 1968-69. They were specially marked. You had to test them to see what section worked and what failed. I made a logic probe with one of the faulty chips by only using two of the gates which worked correctly.
Some ic manufacturers used to sell not fully working silicon... but they called it "sx"
You mean 386SX/486SX ? Always wondered if later 386 were just 486 with bad floating point. I assume yields are still responsible for some of that practice.
Around 1995 there were dirt cheap SRAM chips sold that had no silicon at all
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My first experience with stack problems was way back when the 8085 was quite new, and I was involved with converting an 8080 program to 8085. No logic analyzer in the company then. but did have a o'scope (HP? if I recall) with an two 8 channel D/A capability for X and Y display on the screen.
The program would run for a number of seconds before you'd see a dot moving across the screen. The same pattern every time the program was restarted. THERE! (he said pointing) was the culprit; the stack pointer. Even though there were many pixels of addresses showing up as the program ran, there was only that one (stack) that had to be the problem. That helped debug the problem in the program. I don't recall the detail of the bug (not the same number of PUSHs and POPs, but will never forget how well it showed itself on an x,y plot. Now, burning the 256 byte EPROMs was a chore (program, debug, erase for about 20 min., reprogram). 1702s?
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I do not remember the site but some guys discovered some purposely-bad labeled ics that contained latches instead of the right stuff...a couple of years ago..
Cluso99
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The new chip will also only cost $5, since it's only a little more then half of the original prop. :-)
It was just marching backwards. Thanks for bringing this to our attention!
A P16X64C would be even better :idea:
I recall buying faulty TTL chips cheap ($1 ea) in 1968-69. They were specially marked. You had to test them to see what section worked and what failed. I made a logic probe with one of the faulty chips by only using two of the gates which worked correctly.
You sure that's not the model that the clock ran backwards? :smilewinkgrin:
Around 1995 there were dirt cheap SRAM chips sold that had no silicon at all
The famous WOM, Write Only Memory.
Of course I had a stack program that was kindly referred to as FISH (First In, Still Here). Eventually blew up on stack space.
My first experience with stack problems was way back when the 8085 was quite new, and I was involved with converting an 8080 program to 8085. No logic analyzer in the company then. but did have a o'scope (HP? if I recall) with an two 8 channel D/A capability for X and Y display on the screen.
The program would run for a number of seconds before you'd see a dot moving across the screen. The same pattern every time the program was restarted. THERE! (he said pointing) was the culprit; the stack pointer. Even though there were many pixels of addresses showing up as the program ran, there was only that one (stack) that had to be the problem. That helped debug the problem in the program. I don't recall the detail of the bug (not the same number of PUSHs and POPs, but will never forget how well it showed itself on an x,y plot. Now, burning the 256 byte EPROMs was a chore (program, debug, erase for about 20 min., reprogram). 1702s?
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