From: Markco on
Does anyone happen to know if a 74LS04N hex inverter can be used as a
substitute for a 7404N ? I looked at the data sheets and the pinouts are the
same for both chips. However some of the internals for the inverter circuits
are set up a little differently. I'm thinking about putting together a
simple rs232 interface for the C64 userport and wanted to know if I would
run into problems if I used the other chip as a substitute.

Thanks


From: Brian Ketterling on
Markco wrote:
> Does anyone happen to know if a 74LS04N hex inverter can be used as a
> substitute for a 7404N ?

I think that in most circuitry, you can replace a 74xx with a 74LSxx or
74HCTxx, and the main effect will be lower power consumption.

Brian
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From: Markco on
Thanks Brian. In a c64 that could be a good thing. :-)Planning on putting
together the simple rs232 interface Jeff has the schematic for on the
Petscii site. Got plenty of old circuit boards to cannibalize. If you ever
need a particular chip, let me know I'll see if I can find it here.

"Brian Ketterling" <tweel6510(a)no-potted-meat-products-peoplepc.com> wrote in
message news:85hAh.1030$x74.523(a)newsread4.news.pas.earthlink.net...
> Markco wrote:
>> Does anyone happen to know if a 74LS04N hex inverter can be used as a
>> substitute for a 7404N ?
>
> I think that in most circuitry, you can replace a 74xx with a 74LSxx or
> 74HCTxx, and the main effect will be lower power consumption.
>
> Brian
> --
>
>


From: David Murray on

> Thanks Brian. In a c64 that could be a good thing. :-)Planning on putting
> together the simple rs232 interface Jeff has the schematic for on the

hey.. I wonder how hard it would be to fit the RS232 converter INSIDE
the C64 and put a 9-pin serial port on the back of the C64? I am
positive the original breadbox C64 has room, I'm not sure about the
64C, though. On the other hand, I bet a 128D would be no problem.
That would be pretty neat.

From: Brian Ketterling on
David Murray wrote:
> hey.. I wonder how hard it would be to fit the RS232 converter INSIDE
> the C64 and put a 9-pin serial port on the back of the C64? I am
> positive the original breadbox C64 has room, I'm not sure about the
> 64C, though. On the other hand, I bet a 128D would be no problem.
> That would be pretty neat.

You could put it on a pretty tiny circuit board, so I don't think it would
be a problem. If you're going for a permanent interface, though, you might
use a better circuit, like a MAX232 chip. Another notion would be to
install a Datapump/SwiftLink/Turbo232 type interface, but either case, you'd
be effectively jacking something permanently into either the User Port or
Expansion Port, which could prevent you from connecting other things that
need those lines (U.P.)or that I/O space (E.P.).

Brian
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