1200XL SIO Port Mod

[+Guitarman]

Trying to find the instructions for modding the 1200XL's SIO port for SIO powered hardware.

[Gunstar]

Trying to find the instructions for modding the 1200XL's SIO port for SIO powered hardware.

 

It's real simple, find resister R63, IIRC, it's towards the back of the PCB in the center, just to the right of transister Q3, in the area of the SIO port. Just replace that resister with a jumper wire and your good to go!

Edited March 30, 2007 by Gunstar

[+Guitarman]

Thanks!!! That's it!!

[Curt Vendel]

Adding the 12v line back to the SIO is an easy one, makes no sense why it was left off in the first place. I think Atari was concerned that with its vision of so many selfbooting, self-handler loading SIO devices that would be created for the 1200XL, that many companies might make them power off of the SIO port, and if too many were present it would overload the power supply, damage it and Atari would be left holding the bill for repairs. Just a guess.

 

 

Here are several other 1200XL mods at the bottom of the page -

 

http://www.atarimuseum.com/computers/8BITS...0xl/1200xl.html

 

 

 

Curt

 

 

 

 

Trying to find the instructions for modding the 1200XL's SIO port for SIO powered hardware.

[+Guitarman]

The primary reason for asking (other than the obvious one) is that when using APE/ProSystem with the Atarimax SIO2PC interface and a disk drive, when you run ProSystem, it will not recognize the drive attached because there is not enough line power to activate the SIO2PC. Steve said that hooking up a 600xl/800xl to the SIO chain and turning the power on will allow the drive to be seen. I needed to make a quick disk image and unfortunately the 800 I was working on didn't work, so I grabbed the next thing easily available, one of my 1200XL's. Of course the one I grabbed didn't have the SIO mod yet, so it didn't work either. After modding the 1200XL, it worked fine.