On Fri, Apr 27, 2012 at 6:17 AM, rotaryeng <rotaryeng@earthlink.net> wrote:

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

Paul,

Not sure if this fits your requirement. Have you thought about running
DOSbox under Windows or Linux? It has build in software to redirect
your com port calls into the host OS, which then sends it out via USB
so you don't have to do anything to reach those ports.

DOSbox is open source and available for download. It is a DOS emulator
so you can run DOS program inside. You can of course run it under
Windows 7 if you want.

Henry

No need Henry. The less software between the ports and the software the faster
the response. I got native DOS 5 running on that old IBM Think Pad I had in the hangar.

It has both RS232, USB and a printer port. A printer port in essences is an 8 bit
parallel port so in theory you can use the Think Pad as an EFI computer. Four bits
for coils and four bits for injectors. It is supported in Quick Basic by the POKE or
OUT command.  POKE address, value  The address of the printer port in decimal and the
value is a byte of data with the proper bits set to on. It is that simple.

http://en.wikipedia.org/wiki/PEEK_and_POKE
http://www.aaroncake.net/electronics/qblpt.htm

The ON event is a hardware interrupt and there are several options
that can interrupt the program on TDC e-shaft sensor. I need to test this and
see if it works at 8000 RPM or 133 interrupts per second. Should be
no problem for a 1.3 Ghz notebook running DOS and compiled QB.

The ON key event can trigger on any key board function key so you could hack
the key board with a couple of small wires and short out a key with a solid state
4066 chip turned on by the the CAS. That gives at least ten hardware interrupts.

See what I mean? Direct hardware access.

Excellent site on programming in quick basic in general.
http://www.petesqbsite.com/sections/tutorials/beginners.shtml

http://www.thinkpaddepot.com/

Paul Lamar

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