Atari 1200XL Rambo issue

[JGRAHAM2]

I have a 1200XL with an Atarimax 32in1 OS upgrade, super video upgrade and a Rambo 256K memory upgrade. The problem is that it only reports 112K in XRAM.COM. I have tried various OS versions. There are no other issues. Anyone have an idea what the issue could be?
 

[+Nezgar]

Make sure youre using the latest version of XRAM (0.22) - it was updated in the last few years specifically to handle Rambo's ability to mirror the main 64K as extra banks, and not count them as actual extended RAM:

http://atari.sk/extended-ram-test-0-22-0-xram0220-xex/

 

Maybe post a screenshot too - the usable banks shown may provide a hint.

 

What do other tests show?

Ie:

MEM /X in SpartaDOS X

 

[JGRAHAM2]

I am using .21, so I will check with .22 later today. (And with the others you suggested) 

Thanks!

[JGRAHAM2]

Here is the MEM /X result and my motherboard. Looks like MEM agrees with .21, but .22 sees 64K….

[+Nezgar]

Interesting PIA bits 2 & 3 are inpoerative.... In the 1200XL those are shared by the L1/L2 LED's, so maybe that switch on the back selectively blocks those bits from being used the memory upgrade.

 

Try flipping the switch with the blue/yellow wires leading to it, and run the test again.

[+kheller2]

I could be reading this wrong, but it looks like you have B and D reversed on the Rambo.

 

Page 11 of the RAMBO guide.

[JGRAHAM2]

1 hour ago, Nezgar said:

Try flipping the switch with the blue/yellow wires leading to it, and run the test again.

That switch is part of the super video upgrade.

[JGRAHAM2]

40 minutes ago, kheller2 said:

I could be reading this wrong, but it looks like you have B and D reversed on the Rambo.

 

Page 11 of the RAMBO guide.

Close, but it looks like A and D are reversed. Good eye. In my defense, I didn’t install this, just the 32in1, but whoever did, in general, did good work on the super video and the RAM upgrade. Double checking myself and fixing it now. I’ll report back. Thanks!

[JGRAHAM2]

Looks like that did it, although MEM /X still reports it the same way.

[JGRAHAM2]

SI2 

[+Nezgar]

Nice deduction there @kheller2 and @JGRAHAM2! (Maybe I should become Nezgar2? )

 

I still think something is up there... we should see one more column in column 3, and row $8x should not show. Maybe check that wiring again.

 

Because SI2 thinks $8x has a full 4 banks, it probably thinks you have 256K of extended RAM. Some memory testers mistake that row as extended RAM, when it's really a mirror of the base 64K.

 

Checking a real 1980's RAMBO'd 800XL I have, SDX 4.49c detects 12 banks, not 8, and XRAM 0.22 should look like this:

[JGRAHAM2]

2 minutes ago, Nezgar said:

Nice deduction there @kheller2 and @JGRAHAM2! (Maybe I should become Nezgar2? )

 

I still think something is up there... we should see one more column in column 3, and row $8x should not show. Maybe check that wiring again.

 

Because SI2 thinks $8x has a full 4 banks, it probably thinks you have 256K of extended RAM. Some memory testers mistake that row as extended RAM, when it's really a mirror of the base 64K.

 

Checking a real 1980's RAMBO'd 800XL I have, SDX 4.49c detects 12 banks, not 8, and XRAM 0.22 should look like this:

 

Thanks, I’ll look into it further and report back. It will probably be tomorrow before I can.

[+kheller2]

Check all three jumpers on the rambo, but I also think the ribbon cable to PIA is backwards.  PB6 is pin 16 (far right, black wire) but that wire runs to PB2 on the Rambo (According to the silkscreen).  Hard to see w/o my glasses anymore.

 

[JGRAHAM2]

10 hours ago, kheller2 said:

Check all three jumpers on the rambo, but I also think the ribbon cable to PIA is backwards.  PB6 is pin 16 (far right, black wire) but that wire runs to PB2 on the Rambo (According to the silkscreen).  Hard to see w/o my glasses anymore.

 

@kheller2 There’s nothing wrong with your eyes. The cable was indeed backwards with PB2 going to 16. I wonder if the person that installed it did that to try to fix the issue caused by A and D being backwards…. The video upgrade is far more complex than this and the picture is superb. I ran XRAM .22 and it reported the banks as expected. I’ll try MEM /X later. Thanks to you and @Nezgar for your expert advice.