Some ALDL questions

[Mark Glicksman]

Stephen Thurber wrote:
> 
> Appears to me that this circuit may have the polarity reversed on each
> of the capacitors connected to pins 2 and 6 of the MAX232.
> =======================
> On Sun, 6 Apr 1997, Mark Glicksman wrote:
> 
> > Hello eyeryone,
> >
> >       Well, I have been reading over the archives on ALDL data, and I have a
> > couple of questions that some of you guys may be able to help me with (I
> > hope ;) ).
> >
> > 1) I have been looking at the following diagram........
> >
> > >               +-------------+  +
> > >   +-----------|1          16|---+---o +5V (VCC)
> > >  +|          +|             |  ===
> > >  === +5V o-||-|2  MAX232  15|---+---o GND (card & RS-232)
> > >   |           |             |
> > >   +-----------|3          14|
> > >            +  |             |        o +5V
> > >      +---||---|4          13|        |
> > >      |        |             |        \
> > >      +--------|5          12|        / 10K
> > >           +   |             |        \
> > >      GND o-||-|6          11|        /
> > >               |             |        |
> > >      RxD o----|7  ---<--- 10|--/\/\/-+----------+----o ALDL I/O
> > >               |             |  10K         |\   |
> > >      TxD o----|8  --->---  9|--------------| |--+
> > >               +-------------+             1|/ 2
> > >                                           74LS07
> > >
> > >        (also connect to 74LS07, pin 7=GND, pin 14=VCC)
> >
> > I believe this diagram was submitted by George M. Daily.
> >
> > I noticed that  by pins 2, 4, 6, and between pins 15 & 16, there are
> > capacitors shown, however, there are no values associated with these
> > capacitors, does anyone know what the values of them are?
> >
> > 2) Has anyone actually built this circuit/cable and tried it???
> >
> > 3) Does it work with the 160baud CCC and the 8192baud P4 computers?
> >
> > 4) What does the data output look like after it comes through?
> >
> > I am trying to build this so that I may diagnose my 1987 Buick Park
> > Avenue. (Picked it up for $550.00)  Unfortunately I don't have enough
> > money to afford the Diacom package.
> >
> > Any help with this would be greatly appreciated.
> >
> >                       Very truly yours,
> >                       Mark Glicksman
> >                       mglicksm at suffolk.lib.ny.us
> >

Actually, I am going to have a couple of friend s of mine review this
diagram and 2 others that are similar that I have received recently to
compare and check the logic of all of these designs.  I'll keep you all
updated.

			VTY
			Mark Glicksman
			mglicksm at suffolk.lib.ny.us