DOS? Are you crazy Paul? :)
I was investigating Visual Basic for Windows and I was dismayed at the
complexity.
It is way over kill for what I want to do.
Namely display engine parameters on a note book or net book screen in real
time.
Notebook and net book screens are very large in terms of number of pixels
and cheap.
They can display dozens of engine parameter in a relative small space.
20 some odd years ago I wrote a fully functional aviation moving map
program
in Quick
Basic that ran on DOS driven by a GPS using an RS232 serial interface.
Unfortunately RS232 serial interfaces have disappeared off note book and
net
book
computers.
DOS is a close as anyone is going to get for a real time OS. The down side
to DOS is
it's limited memory management capability. For for my use it is quite
adequate.
Running on a modern computer it is lightening fast bordering on
instantaneous.
The big stumbling block as I see it is the lack of support for USB serial
ports.
That has recently changed. Apparently there are other people out there
that
see the elegant beauty of DOS.
Here is the break through. http://www.georgpotthast.de/usb/
Everything including a full blown EFI can be written in hours using simple
to learn
Quick BASIC. Quick BASIC is a compiled language and the programs are small
and
lightening fast. QB/DOS can handle real time hard ware interrupts which
were
used in my moving map program. The code is already written to read a USB
GPS.
To do an EFI system it is necessary to add hardware of course.
One must design a USB interface board with addressable bit ports to
control
injectors and coils. There are probably some on the market already if I
bother to
look. After that an amplifier must be added to control the injectors. That
could be
as little as an FET power transistor. The modern coils can be controlled
with a computer level bit.
Rather than spend 100's of hours learning VB I am going to look into this
approach
further. I have a real old IBM Think Pad that should run DOS no problem.
No Henry, not the late one I just bought in Shenzhen China last week :)
Paul Lamar
Here is the pin out for the 25 pin connector printer port on many old
notebooks
suitable for running DOS/QB and using it as an EFI computer. Many cheap,
less than
$100, small ATX mother boards also have a parallel printer port and would
also work.
I need to experiment with input Pins 11 and 13 as potential CAS inputs.
QB would see that as an error hardware interrupt. I am sure this goes
through the
assemble language BIOS routines and could be quite fast. I'll trigger
these
lines
with a signal generator and measure the time it takes the Think Pad
computer
to
respond. My guess it is down in the microseconds. The trick here is to get
the HW
interrupt and have a QB program toggle an out put pin with the OUT or POKE
QB
instructions. For those that don't have QB and are interested here it is
in
zip form.
It will run in a DOS or command line window under XP.
All the I/O pins 2 through 9 are self explanatory and would be used to
trigger coils
and fuel injectors.
Don't throw those old notebook computers out just yet:)
Paul Lamar
-----------------------------------------------------
Here is what QB looks like running under DOS on the old IBM Think Pad.
BTW many people are working on USB support for DOS so an ATX mother board
with a USB chip that will boot DOS is all you need. No keyboard display or
hard
drive. The USB chip is big enough to store reams of engine data.
Paul Lamar
---------------------------------------------------------------------------------
I just found some info on the Internet that claims the hidden editor in
Windoze is
the same editor used in Quick Basic. I downloaded it and sure enough it is
identical.
It is now called Edit12.
http://en.wikipedia.org/wiki/MS-DOS_Editor
The other thing I needed was a file manager. Low and behold the best file
manager
ever written, namely Xtree, is still out there and can be downloaded for
free.
Here it is and what it looks like. It is only 43K and not 50 meg like
stupid
windows.
http://www.xtreefanpage.org/lowres/x60softw.htm Of course it is
instantaneous on an
old 530 MHz IBM ThinkPad. Old software newer computer equals super sonic
speeds.
If only Microsh*t had come out with a 32 bit DOS instead of Windoze way
back
when the
world would be a much better place.
It appears that many people agree as the support for old DOS is alive and
well.
Paul Lamar
It is the combination of DOS and Quick Basic. Both allow direct connection
with the
hardware. Quick Basic has hardware interrupt handling built in. We are
looking at
over 100 hardware interrupts in one second.
That cannot be said about Windows or Linux. There is a multitasking
scheduler in
there that is making decision on how much of the resources you are
allowed. You don't
want a powerful multitasking OS. You want something small that gets out of
the way of
your real time program. DOS fits that almost perfectly.
Paul Lamar
---------------------------------------------------------------------
I got the printer port working with the following real simple DOS QB program.
ON KEY (1) GOSUB finished
KEY(1) ON
Start:
OUT &H3BC, 1
OUT &H3BC, 0
GOTO Start
finished:
END
It toggles the first bit (bit 0) on and off in less than 2 microseconds.
This with 530 Mhz IBM Think Pad 560. It would be lot faster with some thing made 20
years later :)
Since you need to delay a coil turning on and off for dwell 2 Milli seconds there is
plenty of time to do other things.
The on key stuff is a hard ware interrupt so you can get out of the infinite loop.
Press function key F1.
BTW this is with interpreted QB. Compiled would be a lot faster.
Paul Lamar
---------------------------------------------------------------------
Here are some pictures of the scope while this program is running.
Note; it take only several hundred nano seconds more for the goto to execute.
If your micro ATX does not have a parallel printer port on board you can buy a
PCI express card.
http://www.softio.http://www.softio.com/ic0652kb.htmcom/ic0652kb.htm
Paul Lamar
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