Re: Digest Number 214

>[I've wired it in solid- no plug. Is it sufficient to turn of the power
>with the switch, or do I need to find the capacitors and drain them?]

The switch will do it. There shouldn't be any big caps in the computer
power supply but there may be in the motor drive system. I'd shut it off
and go away for a bit. Maybe first thing in the morning after a night of
the machine being off.

Ray

[Thanks, Ray. I was just a little nervous about poking around in the
innards of a machine that's still connected to heavy juice- I've had enough
shocks to last me a while...]

Message: 21
Date: Sun, 17 Oct 1999 23:56:15 +0200
From: "Arne Chr. Jorgensen" <instel@...>
Subject: COM cards

Hi,

Okay, first Andrew:

No, not all computers have opto isolators built into their I/O
cards ..... and this is not the parallel port !

[Oh, I thought the object was to connect the parallel port of a new
computer to the input port of the old one, whatever it is (current loop or
RS232). Are you talking about connecting to a serial port instead, or
something else?]

I gave you a simple description about the current loop, but before
that one, I told you about the serial card, ( COM1 or COM2 in DOS )
- and if you have an old IBM ISA card, or a clone of those - then
you have an opto isolator already on that board. This is because
those card had both, RS232 and current loop. You have to select the
mode, by turning around the IC looking part in the socket.

[I do have one of these reversible plugs, as I mentioned- does that mean
I've got a IBM ISA card? (There isn't any marking to that effect) And if
this is the case, I should have an opto isolator on board? If so, would
this be the receiving photo-receptor? As I understand it, these require a
diode for sending and a receptor for receiving- or are they both in the
same unit? There are several optos in the control circuitry, but none I
could identify in the computer itself, unless it looks considerably
different.]

I would send you a drawing or picture if I could, but the Win98 box
is out of order, and I need that in order to scan any picture. Is
there anyone else that has something to help him with ?

I have used it as a communication link to other systems I have
built, but many years ago, - I did use it instead of a tape driver
for a NC control, and some of the other on this list have said (
I think Jon Elson ) that they had some small code that would emulate
a tape drive. ( I don't have my code anymore, or can't find it )

But you have the original tape drive ?

[Yes, but it uses some strange kind of magnetic tape which I'm not sure
even exists anymore- I certainly don't have anything that would write to
it.]

If so, check the wiring. If it is possible to use it, then there
might be some code on the tape. If it is wired as a current loop,
then you may connect it to the interface I described, and dump the
contents of the tape to a file on a computer.

If you don't know what
syntax the code you need to send to your machine, then you could
inspect that file. This could be valuable if this is the only
information you have to go by.


[Attaching the output of the tape drive (which I'm guessing is the 26-pin
connector on a ribbon cable) to a serial port on a new computer? Aside from
the difficulty of working out the pin-outs, I wouldn't know what to do with
the file even if I did get it to transfer. The only tape I got with this
machine is the initialization tape- (in case the machine loses its mind)
and I haven't a clue what language it's written in, not to mention what it
might be telling the machine. But your point about syntax is well-taken- I
hadn't considered how it might want its g-code sent. I suppose there are a
lot of variations possible. It does accept typed-in commands from the
console with its MDI (manual data input) function- these are written in the
standard fashion: eg: G00 x3.5 y4.7 z2.9- but there might be some
translation used between the console and the port.]

Do you have user manuals for the machine ?

[I do, but they don't go into much detail about the inner workings of the
thing- it's mostly about using the existing control system to make parts.]

I did ask you last time - where do you have the photos and such of
this thing ? ( I have waded through the digests, and I can't find
the URL )

[There's a link to it at the bottom of my main page at
<http://www.computersculpture.com>, or you could try
<http://www.computersculpture.com/rammill_page.html>]

Anyway - the idea is to use a computer instead of the tape drive,
and feed the machine.

[That would be great, if I could get it to work.]

( A side note: I assembled a box once, which would convert between
RS232 and a Centronics parallel port. I hooked this on a printer
port, and downloaded it on a computer via this box. The machine
could print out the G-code to a printer, but I was writing a program
that could write the G-codes, so this way I got all the sample
files I needed. I used this to write the program I can't find. This
is 10-15 years ago, so I may have lost it.
This side note, was just to give an idea of how you can do things,
when you don't have other ways to get the info. )

[That sounds similar to what I need, but in reverse- I'd be going from a
parallel port to an RS232- or to that 26-pin connector I keep looking at...]

Andrew Werby

Andrew Werby - United Artworks
Sculpture, Jewelry, and Other Art Stuff
http://unitedartworks.com