Line Driver Question

[Eeyore]

jsalzman@gmail.com wrote:

Are they useful to allow signals to be sent down long wires in serial
communications, like maybe through the house in "dead" CAT3/5 wiring?

You got it.

A'line' is a name for a long cable.

Graham

 

[Michael Black]

(jsalzman@gmail.com) writes:

I collect classic computers and want to archive a lot of my original
software onto modern storage formats. There are many interfaces
available for classic computers to transfer to modern PCs via RS-232.
Since it's impractical for me to get the classic PC next to my primary
desktop PC, I suppose I can try a line driver/receiver adapter and a
run of spare telephone wire or CAT5 (about 45ft in this case) to get
them connected between my workbench and computer desk. That way, if I
don't finish the transfers all in one night, I can just roll up the
wire between sessions. I won't upset my better half by leaving classic
PCs connected up in the den for days.

Open up those computers, and they'll likely have one or more MC1488s and

MC1489s. The only reason they wouldn't is if they are really old, say
forty or more years old, or recent enough that the function was integrated
into a larger IC, or it used one of the RS-232 line drivers and receivers
that came much later but never had the penetration of the 1488 and the 1489.

Wherever there's RS-232, there will be a line driver and receiver of some
sort.

Michael

 

[whit3rd]

On Mar 4, 5:42 am, jsalz...@gmail.com wrote:

Thanks for the info. I have an original 5150 I can try that on, but
the computers I'm referring to are non-IBM. Commodore 64, Apple II,
TI-99, TRS-80, etc. There's RS-232 style solutions for these.

The native interfaces on some of those oldies included cassette tape,
probably on the Kansas City protocol (frequency-shift bit encoding).
Your easiest transfer solution might be to hook 'em into the
sound card input/output ports on a modern-ish PC.

The 'original' PC was not equipped with hard drive, nor (except
as an extra-cost option) with floppies. It had a DIN plug on the
back for cassette tape.

 

[Lord Garth]

<jsalzman@gmail.com> wrote in message
news:71d62145-43cc-4946-a247-3143a9dc8ee7@i7g2000prf.googlegroups.com...

You can implement the very old Intel hex routine on the ancient computer
data
to convert the programs to ASCII hex. You then 'print' the ASCII hex to
the
serial port. The modern computer can (in DOS for sure) have its console
redirected to com1. It will appear as if someone typing the ASCII hex
very
rapidly to the modern computer. I believe that command was 'mode
con:=com1:'

You can then use debug to convert the ASCII hex back into binary data and
save the program to modern media.

Thanks for the info. I have an original 5150 I can try that on, but
the computers I'm referring to are non-IBM. Commodore 64, Apple II,
TI-99, TRS-80, etc. There's RS-232 style solutions for these. I just
need to implement the connections.

There are 8080 / Z-80 assembly code examples of the Intel hex program, see
if you can find these. Of course, if your program to be saved is in
assembly or
basic or some other printable form, just list it to the serial port.

I did this long ago to move paint formulas for Roach Paint from a Sol S-100
computer to an IBM PC.

 

You can implement the very old Intel hex routine on the ancient computer
data
to convert the programs to ASCII hex. You then 'print' the ASCII hex to the
serial port. The modern computer can (in DOS for sure) have its console
redirected to com1. It will appear as if someone typing the ASCII hex very
rapidly to the modern computer. I believe that command was 'mode
con:=com1:'

You can then use debug to convert the ASCII hex back into binary data and
save the program to modern media.

Thanks for the info. I have an original 5150 I can try that on, but
the computers I'm referring to are non-IBM. Commodore 64, Apple II,
TI-99, TRS-80, etc. There's RS-232 style solutions for these. I just
need to implement the connections.

 

[Lord Garth]

<jsalzman@gmail.com> wrote in message
news:8deb2bbc-6912-4090-8e34-8c68eb555020@c33g2000hsd.googlegroups.com...

On Mar 3, 2:17 pm, et...@FreeNet.Carleton.CA (Michael Black) wrote:
But there's the example that proves you need the specific IC number.

The MC1488 is very specific, it's intended as an RS-232 line driver,
to go with the MC1489 RS-232 line receiver. Since RS-232 uses positive
and negative voltages, they generally won't be useful except if your
need is for positive and negative voltages. I can't remember but they
also may not be particularly good sources of current output, instead
they are designed for driving long lines rather than loads that put a lot
of drain on the lines.

I'll have to check and see if I have an MC1489 then. I might actually
have a use for the pair.

I collect classic computers and want to archive a lot of my original
software onto modern storage formats. There are many interfaces
available for classic computers to transfer to modern PCs via RS-232.
Since it's impractical for me to get the classic PC next to my primary
desktop PC, I suppose I can try a line driver/receiver adapter and a
run of spare telephone wire or CAT5 (about 45ft in this case) to get
them connected between my workbench and computer desk. That way, if I
don't finish the transfers all in one night, I can just roll up the
wire between sessions. I won't upset my better half by leaving classic
PCs connected up in the den for days.

Thanks!

You can implement the very old Intel hex routine on the ancient computer
data
to convert the programs to ASCII hex. You then 'print' the ASCII hex to the
serial port. The modern computer can (in DOS for sure) have its console
redirected to com1. It will appear as if someone typing the ASCII hex very
rapidly to the modern computer. I believe that command was 'mode
con:=com1:'

You can then use debug to convert the ASCII hex back into binary data and
save the program to modern media.

 

On Mar 3, 2:17 pm, et...@FreeNet.Carleton.CA (Michael Black) wrote:

But there's the example that proves you need the specific IC number.

The MC1488 is very specific, it's intended as an RS-232 line driver,
to go with the MC1489 RS-232 line receiver. Since RS-232 uses positive
and negative voltages, they generally won't be useful except if your
need is for positive and negative voltages. I can't remember but they
also may not be particularly good sources of current output, instead
they are designed for driving long lines rather than loads that put a lot
of drain on the lines.

I'll have to check and see if I have an MC1489 then. I might actually
have a use for the pair.

I collect classic computers and want to archive a lot of my original
software onto modern storage formats. There are many interfaces
available for classic computers to transfer to modern PCs via RS-232.
Since it's impractical for me to get the classic PC next to my primary
desktop PC, I suppose I can try a line driver/receiver adapter and a
run of spare telephone wire or CAT5 (about 45ft in this case) to get
them connected between my workbench and computer desk. That way, if I
don't finish the transfers all in one night, I can just roll up the
wire between sessions. I won't upset my better half by leaving classic
PCs connected up in the den for days.

Thanks!

 

[Lord Garth]

<jsalzman@gmail.com> wrote in message
news:97d6a409-8ac7-4a4d-b88f-270ef78d2a21@s8g2000prg.googlegroups.com...

Can you include the part number so that the datasheet can be studied?

Sorry, I didn't realize they might be that specific to different
application needs. I thought they were about as general as an op-amp
or something, just requiring the application to fit within the part's
specifications.

I have several part numbers in my small inventory, but I'm at work,
and away from my workbench for the day. One part number that sticks
out in my mind is MC1488

On another note, How would I test a line driver for basic operation?
Feed it a signal and see if the signal appears on the output also?

The 1488 is an RS-232 output buffer. It require a bipolar power supply,
meaning +12V & -12V.

The part takes 0V to 5V input and outputs -12V to +12V in accordance
with the specification for RS-232 serial ports.

The other part is likely the LM-1489. This receiver uses a single supply
voltage
and takes the +12 -12 input back to TTL 0 to 5 volt levels.

If you wish to drive very long lines, these are not the buffers to use.
300 feet at low baud rates are possible though the higher the speed,
the shorter the run.

Today, a differential interface is more desirable. Driving 1000 to 5000
feet is possible. Your old chips are single ended meaning that the
voltages are with respect to ground. A differential driver is not
ground refered.

 

[Michael Black]

(jsalzman@gmail.com) writes:

Can you include the part number so that the datasheet can be studied?

Sorry, I didn't realize they might be that specific to different
application needs. I thought they were about as general as an op-amp
or something, just requiring the application to fit within the part's
specifications.

I have several part numbers in my small inventory, but I'm at work,
and away from my workbench for the day. One part number that sticks
out in my mind is MC1488

But there's the example that proves you need the specific IC number.

The MC1488 is very specific, it's intended as an RS-232 line driver,
to go with the MC1489 RS-232 line receiver. Since RS-232 uses positive
and negative voltages, they generally won't be useful except if your
need is for positive and negative voltages. I can't remember but they
also may not be particularly good sources of current output, instead
they are designed for driving long lines rather than loads that put a lot
of drain on the lines.

Other line drivers would be designed for other specific standards.

Then you have drivers intended for loads such as relays.

On another note, How would I test a line driver for basic operation?
Feed it a signal and see if the signal appears on the output also?

That's about it. Some may invert signal, others won't. If you see
the input reflected in the output, they probably are good (though
make sure to feed the input with both a "high" and a "low" voltage
to ensure that the output really follows the input, since if it's
damaged the output might be stuck at some voltage.

Michael

 

[Meat Plow]

On Mon, 03 Mar 2008 09:37:03 -0800, jsalzman wrote:

I have a bunch of chip pulls that are called Line Drivers (single,
dual, quads). Nothing seems to pop-out when searching for the best use
for a line driver. This is what I figured out so far:

Line drivers are used to "drive" a signal IN to the OUT and offer more
current/voltage for the output. Basically "beefing up" and/or
protecting what's connected to the Input.

Their specifications vary and are best selected based on max current
and voltage listed in the datasheet as needed for any particular
circuit application.

The output signals are identical in shape to the input, but are
delayed by a fraction of time and may or may not be a different
voltage.

Am I on the right track here? As a hobbyist, what would I want to use
these for except to drive a bunch of LEDs directly or something. Are
they useful to allow signals to be sent down long wires in serial
communications, like maybe through the house in "dead" CAT3/5 wiring?

My take is a line driver maintains the level and integrity of a
voltage/signal/etc....

 

Can you include the part number so that the datasheet can be studied?

Sorry, I didn't realize they might be that specific to different
application needs. I thought they were about as general as an op-amp
or something, just requiring the application to fit within the part's
specifications.

I have several part numbers in my small inventory, but I'm at work,
and away from my workbench for the day. One part number that sticks
out in my mind is MC1488

On another note, How would I test a line driver for basic operation?
Feed it a signal and see if the signal appears on the output also?

 

[Lord Garth]

<jsalzman@gmail.com> wrote in message
news:926b201f-004b-45ff-b31f-3a135afc43f0@s19g2000prg.googlegroups.com...

I have a bunch of chip pulls that are called Line Drivers (single,
dual, quads). Nothing seems to pop-out when searching for the best use
for a line driver. This is what I figured out so far:

Line drivers are used to "drive" a signal IN to the OUT and offer more
current/voltage for the output. Basically "beefing up" and/or
protecting what's connected to the Input.

Their specifications vary and are best selected based on max current
and voltage listed in the datasheet as needed for any particular
circuit application.

The output signals are identical in shape to the input, but are
delayed by a fraction of time and may or may not be a different
voltage.

Am I on the right track here? As a hobbyist, what would I want to use
these for except to drive a bunch of LEDs directly or something. Are
they useful to allow signals to be sent down long wires in serial
communications, like maybe through the house in "dead" CAT3/5 wiring?

Can you include the part number so that the datasheet can be studied?

 

I have a bunch of chip pulls that are called Line Drivers (single,
dual, quads). Nothing seems to pop-out when searching for the best use
for a line driver. This is what I figured out so far:

Line drivers are used to "drive" a signal IN to the OUT and offer more
current/voltage for the output. Basically "beefing up" and/or
protecting what's connected to the Input.

Their specifications vary and are best selected based on max current
and voltage listed in the datasheet as needed for any particular
circuit application.

The output signals are identical in shape to the input, but are
delayed by a fraction of time and may or may not be a different
voltage.

Am I on the right track here? As a hobbyist, what would I want to use
these for except to drive a bunch of LEDs directly or something. Are
they useful to allow signals to be sent down long wires in serial
communications, like maybe through the house in "dead" CAT3/5 wiring?