Hi Hal:
Yes for level shifting. Most micro controllers have the UART built-in so
that's all that's needed.
I haven't got my boxes so don't know what chips are in them.
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Brooke Clarke
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Hal Murray wrote:
bro...@pacific.net said:
UARTs are not mandatory, a simple transistor level shifting circuit is all
that's needed for TTL/RS-232 levels.
I think you are confusing UARTs with level shifters.
In the old days, transistors were expensive enough that a 68000 class CPU was
all that could fit on a chip. All memory and peripherals were off chip.
While not quite mandatory, most of the time it made sense to use a UART chip.
If you had a FPGA, you could put a simple UART in there. (But back then,
FPGAs weren't very big either.) If the CPU was idle, you could bit-bang
things.
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