On a sunny day (Fri, 14 Jun 2013 22:20:58 -0800) it happened Robert Baer wrote in :
Mobo defective? You read the pins from the wrong side (numbers reversed)? This works just fine here (test setup so I can test i2c chip based modules in C from the PC), before doing that asm stuff in a PIC):
/* i/o used: parallel printer port for iic bus interface diodes in 25 pol connector If iicbus 0 selected (default iicbus_select = 0) scl pull down bit 5 0x378 pin 7 (d5) via 1N4148 diode
----|
According to the original IBM documentation viz IBM Technical Reference First Edition August 1981 page D-34 Parallel Printer Adapter schematic, the following pins of the DB-25 printer connector are exclusively inputs: pin 13 is +SLCT (select, high for "1") pin 11 is +BUSY (busy, high for "1") pin 12 is +PE (paper out, high for "1") pin 10 is -ACK (acknowledge, low for "1"; eg: inverted logic)
So, how come with computer NOT CONNECTED to anything (NO power at all), one sees that pins 10, 11 and 12 are SHORTED TO GROUND?
Please explain how a printer can possibly work with that condition.
Not a solution, but isn't using the printer port sure to introduce problems when your PC needs to be updated and you cannot find one with a printer port?
Regards
Klaus
How old is that parallel cable?
Because they have evolved over the years as has the comm link hardware and specs.
Maybe that is a cable from before such signals were 'looked at'. Or maybe it isn't really a real parallel cable, and you grabbed the wrong item.
Have you opened (or beeped) another cable end to compare?
The solution costs only three Dollars :-)
Even if you did some odd hardware tricks where a Windows driver may not suffice you can still buy brand-new ISA bus PCs with LPT, RS232 and all that. A client was once a bit panicked when their old in-circuit tester PC croaked. It was well over 20 years old. But within less than a week it was all operational again, running DOS, with LPT and numerous RS232 ports. The only real difference was that the new PC also had a CD drive.
-- Regards, Joerg http://www.analogconsultants.com/
We have a programmer that needs to be supported for a few old PLC's that still operate, they call it a PIC programmer, not to be confused with a Microchips PICS.
This unit requires parallel port which isn't too too bad, however, the USB to Parallel port devices don't seem to deliver the power requirements to operate this device. So I placed a DC jack on the programmer so that a wallwart can operate the higher currents, but I also had to put a high side switch in it because the software for it wanted to toggle this line to the device.
It all works find now.. I modified a couple PIC programmer interfaces for some people I know that work out in the field. They'd be happy as flies buzzing around a pile of turd!
Jamie
C from the PC),
connector
----| If iicbus 1 selected
----| iicpower bit 3 0x378 pin 5 (d3) */
First, i measured this on three different Personal Computers, NOT on any (untested yet) hardware that you referred to. Second, they drive printers in the normal expected manner. Third, pinning/pin number VS function has been verified umpteen times; no mistrakes.
Then it depends. I remember a programmer for the Texas MSP430 that was not happy with USB-LPT adapters but did work with PCMCIA-LPT adapters.
Parallel port cards for PCI are still availaible:
They have lots more.
-- Regards, Joerg http://www.analogconsultants.com/
WOW, lots more must mean leftover stock.
I got mine 10 years ago for $4.95 !!
>
Some are still being made. Just like ISA bus motherboards and computers are:
If you need a parallel port card for that bus for some reason:
So now you know the real inflation numbers :-)
-- Regards, Joerg http://www.analogconsultants.com/
The original port was single direction, output only, with handshaking. The newer ports are bi-directional.
There have been two additional versions of the printer port implemented since the original PC.
Here is some basic information on the types most likely in use on your computers.
Modern printers talk to the computer on the bi-directional data bus, and no longer need those lines.
On a sunny day (Sat, 15 Jun 2013 09:29:31 -0800) it happened Robert Baer wrote in :
I do not see the problem. When I ordered this (simple) PC last year, or was it this year, latest simple ASUS mobo, I knew it had a par port header (not a connector), and I ordered a PCI par port card (with its own chip as you mentioned) with it for a little more than 10 Euro (from Germany). Only problem was figuring out the funny par port address from that card, it was 0xec00, the header on the mobo is 0x378. Anyways it works great, and protects the mobo. Yes it drives the PIC noppp (Noparts Pic Programmer, Jamie), but if you are REALLY paranoid about damaging the PC, here I am using a 35 $(or so) Raspberry Pi as PIC programmer via ssh (ethernet):
so the limitations are not really there at all if you can melt some solder and flip some bits.
BTW what is a short? How do you measure that? 0.00 Ohm?, diode drop?, maybe them CMOS are 'on' if no supply? (depletion not sure aboput that?)
As I stated. That is PRE-bi-directional parallel spec was used. It existed, It just did not get used yet. Something you were/are apparently unaware of.
Also, check your mobo parallel port settings. There are different choices depending on what you intend to use it for.
Nice. Incredible they can do that for 3 USD
Cheers
Klaus
I've seen "that condition" destroy printers. turn the power on an re-measure.
-- ?? 100% natural --- news://freenews.netfront.net/ - complaints: news@netfront.net ---
yeh, at least one chip an xtal, pcb, two connectors wire and some plastic
even if you stole the parts it is hard to see how it is possible to make it for that price
-Lasse
Even on EPP, those lines are still inputs, so most likely the port is Kaput.
Cheers
On all his computers?
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