Re: OT: DOS programming EPP


"PaulCsouls" <paulcsouls@xxxxxxxxxxxxxxxx> wrote in message
news:sfh7t1hl57573mbnqbesvj9ktgdmufd82p@xxxxxxxxxx
> On Sun, 22 Jan 2006 03:14:06 GMT, Robert Baer
> <robertbaer@xxxxxxxxxxxxx> wrote:
>
>> I have done a websearch, and there is nothing available that
>>eXplicitly shows how to program a parallel port in the EPP mode, and how
>>to *safely* interface with it.
>> The best (incomplete) source i found was on the beyondlogic.org site.
>> However, no matter what i do, the nominally input printer pins (pin 1
>>= strobe, pin 13 = select and pin 15 = error bar) act like outputs.
>> Data lines when low safely sink 2mA (did not try more as i did not
>>want to zap the MB) R=45 ohms, and when high safely source 1mA (did not
>>try more R=2.2K).
>> "Strobe" line pin 1 was always high and safely sink 1.5mA R=730 ohms.
>> "Select" line pin 13 was always high and safely sink 1.0mA R=2.2K.
>>
>> There seems to be *no* specifications or equivalent circuits for the
>>parallel port as implemented on the ASICs used in modern PCs.
>> Therefore, it is completely unknown as to the maximum safe sink
>>current to a logic low pin or the maximum source current from a logic
>>high pin.
>> It is not wise to force a pin that is acting as an output, into the
>>opposite state; so the info is necessary for safety.
>>
>> I want and need to program this in DOS.
>>
>>** as an aside, it was interesting to see that when Windoz booted after
>>my fiddling, that i saw "detecting new hardware" etc.
>
> Go back to the beyond logic page and read the parallel port FAQ from
> the beginning. The EPP page assumes you did. You need to set up the
> extended control register (BASE + 0x400). In EPP mode Strobe is the
> WRITE/NOT READ bit and an output.
> I think you need to do some C or BASIC code to do any of this. I don't
> think you can just use DOS shell commands.
>
> Paul C

Coming into this thread late but I've set the parallel port on my PC to
different modes through the BIOS.

Robert


.

Relevant Pages

  • Re: OT: DOS programming EPP
    ... There seems to be *no* specifications or equivalent circuits for the parallel port as implemented on the ASICs used in modern PCs. ... it is completely unknown as to the maximum safe sink current to a logic low pin or the maximum source current from a logic high pin. ... The EPP page assumes you did. ... This way of programming was used by the old "standard" printer interface. ...
    (sci.electronics.design)
  • Re: OT: DOS programming EPP
    ... >eXplicitly shows how to program a parallel port in the EPP mode, ... > However, no matter what i do, the nominally input printer pins (pin 1 ... >parallel port as implemented on the ASICs used in modern PCs. ... think you can just use DOS shell commands. ...
    (sci.electronics.design)
  • Re: OT: DOS programming EPP
    ... >>> parallel port as implemented on the ASICs used in modern PCs. ... >>> to a logic low pin or the maximum source current from a logic high pin. ... The EPP page assumes you did. ... This way of programming was used by the old "standard" printer interface. ...
    (sci.electronics.design)
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    ... Is a 2 k-ohm resistor big enough? ... PWM motor control via parallel port. ... in a 16 pin DIP and provides 7 darlington transistors ... but the gate voltage is low. ...
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  • Re: OT: DOS programming EPP
    ... There seems to be *no* specifications or equivalent circuits for the parallel port as implemented on the ASICs used in modern PCs. ... it is completely unknown as to the maximum safe sink current to a logic low pin or the maximum source current from a logic high pin. ... The EPP page assumes you did. ... CONTROL bit 5 defaults low. ...
    (sci.electronics.design)