SIO pin spacing: perf board follies

[Smokeless Joe]

I'm trying to custom make/modify an SIO peripheral. I desoldered a couple female SIO ports and I'm trying to mount them on a standard perf board with 0.042 inch diameter holes in a 0.1 x 0.1 inch grid pattern. But the spacing of the pins on the port is really weird and does NOT line up with the grid pattern (see attached picture).

 

The pin spacing is a shade over 1/8" or 3 mm. I suppose I could find a 0.042 inch drill bit (#58) and make my own holes, but damn.

 

Which leads to my questions:

 

1. Does anyone know the precise pin spacing specification of a female SIO port?

 

2. Is there anywhere in the world that makes perf boards to fit such a spacing?

 

Thanks!

 

 

 

 

 

 

 

[hendersonn]

The only solution I can think of at the moment would be to solder some extensions to the ends and bend them slightly to fit into place. I had to do something similar when prototyping an edge card connector. Tedious, but it got the job done.

[low.blow]

Maybe not the most professional solution, but what I did is lined up and cut a hole in the perf board that all of the pins fit through - then bolted the tabs on the sio connector to the perf board. Then just soldered my ribbon cable directly to the pins. Perhaps not the best solution, but it is very solid.

[Rybags]

To me the spacing looks to be exactly 3.5mm and a gap of 3mm between the top/bottom rows of pins.

 

So a DIY solution might be called for, next best bet would be find a board with 3.5mm spacing then elongate one lot of holes to allow that 3mm gap (assuming the angled part retains the same spacing between the rows)

[Audronic]

@ Smokeless Joe

 

Is it possible to just bend the pins to suit the board ?

 

Good Luck

 

Ray W

[Kr0tki]

1. Does anyone know the precise pin spacing specification of a female SIO port?

Search for SIOSPECS.PDF.

[ricortes]

Rotate 45 degrees. You have to bend out/separate the pins by maybe 50 mils. Too late to figure out if it is (.1)sqrt(2) bend factor.

[+hunmanik]

Search for SIOSPECS.PDF.

 

Regarding SIO pin 12...

 

On page 8 of this document (page 12 of the PDF), it says SIO pin 12 is "300 mA regulated" while further down the same page it appears to say "Line 12 is regulated +12 V dc at 100 mA."

 

On page 17 of this document

http://www.atarimuseum.com/ahs_archives/archives/pdf/computers/8bits/1200XL/sweet-16_prodspecs.pdf

it says "Pin 12 of the Atari 400/800 SIO connector is 12-volts, 300 ua of direct current."

 

So I remain a bit unsure about the current available on pin 12 on the 400/800. Is the value 100 or 300, and are the units milliamps (mA) or microamps (uA)?

 

I suppose someone with the proper tool and a 400/800 or two could easily measure and confirm what current is actually there?

[Rybags]

Current ratings quoted for ports are in milliamps.

Note only the 400/800 have the +12V available, it's not present on any other model.

 

To measure current you need to load the circuit and have do the measurement in series.

[Smokeless Joe]

Thanks for the all the info and ideas. Now I just have to decide how to proceed.

 

I'm particularly amused by Ricortes's revelation that rotating a standard perf board 45 degrees creates the proper spacing (with some bending of the rows). A little Pythagorean calculation using a 0.1 inch grid gives a spacing of about 0.14 or about 1/7 an inch. Crazy.

[+hunmanik]

Make that page 70, not page 17

 

On page 17 of this document

http://www.atarimuseum.com/ahs_archives/archives/pdf/computers/8bits/1200XL/sweet-16_prodspecs.pdf

it says "Pin 12 of the Atari 400/800 SIO connector is 12-volts, 300 ua of direct current."