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korn0051

Connecting the 4A to the Epson MX-80

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Hi everyone,

 

I've been piecemealing together a full 4A system for a couple years now, and my latest addition is leaving me stumped.  I've searched through the forums and didn't see anything that quite answers my questions, so I'll throw it out here if there's an expert that knows.

I have the PEB with the RS232 card.  The cord is a 25-pin (at the PEB) to 36-pin (at the MX-80).  All seems good and well, I power up the MX-80 and get the POWER, READY, and ON LINE lamps.  But when I turn on the PEB, the READY lamp turns off.  Another oddity: if I disconnect the TI-99 from the PEB and turn on the PEB, the READY lamp stays on.

 

I'm guessing it is either an issue with the pinout of the cord or the DIP switch settings on the MX-80's main board.  Any recommendations of cables or DIP settings from others that have the MX-80?

 

Thanks!  Aaron

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Hi everyone,
 
I've been piecemealing together a full 4A system for a couple years now, and my latest addition is leaving me stumped.  I've searched through the forums and didn't see anything that quite answers my questions, so I'll throw it out here if there's an expert that knows.
I have the PEB with the RS232 card.  The cord is a 25-pin (at the PEB) to 36-pin (at the MX-80).  All seems good and well, I power up the MX-80 and get the POWER, READY, and ON LINE lamps.  But when I turn on the PEB, the READY lamp turns off.  Another oddity: if I disconnect the TI-99 from the PEB and turn on the PEB, the READY lamp stays on.
 
I'm guessing it is either an issue with the pinout of the cord or the DIP switch settings on the MX-80's main board.  Any recommendations of cables or DIP settings from others that have the MX-80?
 
Thanks!  Aaron
The cord should be this one for centronics


https://iec.net/product/ti99-4-parallel-printer-cable-5/


25 pin is serial not parallel on the TI card the parallel port is below it

Sent from my LM-G820 using Tapatalk

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You are trying to connect the serial port (25 pin) to a Centronics parallel interface (36 pin) on the printer. Any standard Centronics parallel cable will work assuming you have it plugged into the parallel interface on the RS232 card. 

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You actually want the standard printer cable for an EPSON, not the Smith Corona or Okidata cables. The latter two had some logic in the cable to reverse polarity of some of the control signals (Hold, IIRC) and to synthesize some of the missing control signals. Bonus is that it costs less. . .

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42 minutes ago, Ksarul said:

You actually want the standard printer cable for an EPSON. . .

Wow, that's almost identical to the one I put together 30-some years ago (Pic is from iec link above). Not a bad price either, plus you don't have to look up the pinout or strip and solder the fine ribbon conductors.

-Ed

TI_Centronics.jpg.aa02084bb2a610e29d1811997779cca0.jpg

 

And my tagline seems unusually appropriate here in this thread. :-D

Edited by Ed in SoDak
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10 hours ago, Ksarul said:

You actually want the standard printer cable for an EPSON, not the Smith Corona or Okidata cables. The latter two had some logic in the cable to reverse polarity of some of the control signals (Hold, IIRC) and to synthesize some of the missing control signals. Bonus is that it costs less. . .

Did not know that. Thanks for the info :)

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Thanks everyone for the cable advice.  I have a parallel/parallel cable on order.  I'm thinking between that and the patchy documentation on DIP switches that should solve the issues.  Once I have the cable and get the DIP switches set, I'll post that for the next poor soul trying to connect devices.

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On 12/31/2019 at 3:59 AM, Ed in SoDak said:

 

Wow, that's almost identical to the one I put together 30-some years ago (Pic is from iec link above). Not a bad price either, plus you don't have to look up the pinout or strip and solder the fine ribbon conductors.

-Ed

TI_Centronics.jpg.aa02084bb2a610e29d1811997779cca0.jpg

 

And my tagline seems unusually appropriate here in this thread. :-D

do you have the schematic of this cable ?

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I’m looking for a serial card for one of these if anyone has one not being used.

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20 hours ago, fabrizio said:

do you have the schematic of this cable ?

Same here, just like what I had. Must if been popular.

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Sorry! I wired it up in the mid-'80s using the Epson and TI RS232 manuals. If there's anything, at best it's a handwritten note in the bottom of one of the boxes containing bits and pieces of my old TI stash. Easier to dig out the cable, open the printer connector and trace wires.

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I have a bunch of things taking up space that I want to get rid of (as a package deal only).

 

Contents:

1) An RS-232 cable.  I do not know which printer it works with, so you'll probably have a 50/50 chance of it working out of the box.

2) A TI RS-232 Y-Cable

3) A Lantronix UDS-10 with power supply.

4) A modified TI RS-232 card you'll have to perform an operation if you want it to run as RS232/1 again.

 

ITEMS.thumb.JPG.e61bc0137a60985087c2d1e1f7e290ac.JPG CLICK ON IMAGE TO ENLARGE VIEW

 

If you're interested, and live in the lower 48 states, send me a PM.  I'll let it all go for $150.00 (which includes shipping).  Sorry, PayPal only.

Everything was working when I pulled it from my system after I switched to the TIPI.

 

 

 

 

 

 

 

 

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