Atari 600XL Antonia 4MB Install, Firmware Update and/or EXTSEL required

[+slx]

I just opened my 600XL to install Antonia 4MB.

 

AFAIK there is no other mod on the MB (a capacitor and a resistor are soldered to one pin of the UHF modulator). The Motherboard has a "Rev. A" stamped next to the joystick connectors and says CO 61677 7/1983 Rev X9B on the bottom).

 

Do I have to attach EXTSEL if

 

• I want to use an Ultimate Cart with that machine?
• I want to use SIDE2?

or is this only required if I use the old firmware (no Idea which one I have).

 

I also read something about taking out the delay lines (CO60472) and shorting two pins of the socket. Is this required, optional, required in certain cases only?

 

Thanks for your help!

 

While the machine is open, is there anything else of use that can be modified to improve operation? The SIO2SD page mentions adding a resistor and removing capacitors from DATAIN/DATAOUT but doesn't name where they're located on a 600XL.

 

(I do have a Rev. B UAV here but will try the stock video before deciding on an upgrade.)

[Simius]

EXSEL isn't required using any cartridge. It is only required when a PBI device (like IDE+) is connected. You don't need to do anything with the delay line.

[shoestring]

Capacitors to be removed connect DATAOUT and DATAIN with ground. Those are small, 100nF capacitors (looks like resistors). In 800XL, 65XE and 130XE computers they have numbers C77 and C78. To show the difference please look below at oscillograms - with and without those capacitors.

 

C77 and C78 are actually 1nf capacitors. .001uf = 1nf

 

In the 600xl the capacitor locations which are tied between datain/dataout and ground are C89 and c90.

Edited June 16, 2017 by shoestring

[+slx]

Thanks for your help! Any hints on where C89/90 are on the Motherboard, as most components neatly Cover their component number?

 

And how can I tell whether that 4K7 resistor is present?

 

 

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[shoestring]

I'll open up my 600xl and take a look.

 

I'm a little confused by where the 4k7 resistor is supposed to go. So maybe someone else can chime in and clear things up. The 600xl schematics already show a resistor between DATAOUT and +5v @ R76 but the sio2sd site goes on to say between pin 1 and 5 of SIO connector ?. Pin 5 is DATAOUT but pin 1 is the clock input, pin 10 appears to be +5v.

[+slx]

I think I have found those caps. I was fooled by "caps looking like resistors" .

 

I found the "silkscreen" graphics in the 600XL field service manual:

 

And here they are in real life:

 

 

Unsoldered one leg of C90 and ripped apart C89 trying to do the same...hope I never need to re-attach these....

 

Antonia mounted, 600XL still working, even though the long time required for the RAM to lose contents is a bit of a nuisance. Is there an OS that I can flash that allows for a coldstart with a button combo?