1200XL + SIO2SD: Odd behavior compared to 800XL and XEGS

[rockman_x_2002]

A little background:  This weekend, I acquired a 1200XL with the 5V SIO mod done to it so I can use self-powered devices like the SIO2SD.  Before this, I already owned an 800XL and a XEGS, and I have two SIO2SD devices (one bare board, and one in a nice case, both from Lotharek), and a MyIDE-][ cart (but that's not the subject of this particular post).

 

I'm seeing some odd behavior out of the 1200XL when trying to use the SIO2SD, and I'm wondering if it's due to some difference in the OS that I'm not aware of.  I've tried searching on this forums and various other places across the Internet, and I haven't quite found anything quite like I'm seeing.  Here's the details of the hardware setup:

 

• The 1200XL is running Rev 11 OS
• Both SIO2SD devices are on firmware 3.1 RC2
• I have both the original and 400/800 fixed versions of the SIO2SD Configurator v3.5 (SIO2SD.XEX) on a 2GB SD card

 

When I boot the original version of SIO2SD.XEX, the configurator behaves differently than what I see on the 800XL.  For example, whenever I choose a directory on screen, it takes an extremely long time to actually load the access the SD card.  When it finally finishes, instead of refreshing the bottom half of the screen and showing just the directory's contents, it just adds the directory's contents below what's already there.  If I press the inverse video key to force a refresh, it just spits the directory contents again below what's there.  Sometimes, a directory fails to load at all, though, and pressing the inverse video key seems to joggle it and make the directory output.  Likewise, pressing and holding the "X" key to load the disk image(s) selected takes forever for the computer to actually reset and start loading.

 

If I swap to the fixed version of SIO2SD.XEX for the 400/800, the directory loading seems to work properly.  However, if I attempt to assign a .ATR image, an exclamation point appears at a random location on the screen, and the computer freezes.  Likewise, if a disk image is already present, and I press and hold the "X" key to load, a "k" character appears in the top-left corner of the screen, and the computer again freezes up.

 

The other issue seems to occur with only certain games when loaded.  For example, with Rescue on Fractalus! (1985 Epyx disk), the game appears to load fine.  But after pressing the "Start" key, and after descending onto the planet, when the mountains begin to load, the graphics glitch out, and the game ultimately crashes.  Other games, however, like The Eidolon, or even simpler games like Q*Bert and Star Raiders, seem to load perfectly fine.

 

As a side note, loading Fractalus! cart image for the XE (1987) via MyIDE ][, incidentally, seems to work just fine.  Likewise, using the original v3.5 SIO2SD.XEX on both the 800XL and XEGS loads all games correctly, including the aforementioned version of Fractalus!.  The MyIDE ][ behaves exactly the same in the 1200XL as it does on the 800XL and XEGS, and nothing immediately stands out as an issue with the 1200XL itself.

 

Is there something that I'm missing regarding the 1200XL that's different from the 800XL and XEGS, such as some difference in the OS, or has anyone ever run into this issue?  I'm at work at the moment, and won't be able to fire up the 1200XL until later, but if pics of the screen for the above problems would be helpful, I'll be glad to post those.

[_The Doctor__]

I sometimes run the 5v from the power switch to the sio on the 1200XL, lifting the resistor out and leaving it out and most every time protecting it with low v drop diode... the sio2sd is power hungry... as to all the rest... I'd give the 1200XL a thorough testing, memory et all... are there any other modifications in the 1200XL? Have you tried the other menu select screen revisions?

[rockman_x_2002]

5 hours ago, _The Doctor__ said:

I sometimes run the 5v from the power switch to the sio on the 1200XL, lifting the resistor out and leaving it out and most every time protecting it with low v drop diode... the sio2sd is power hungry... as to all the rest... I'd give the 1200XL a thorough testing, memory et all... are there any other modifications in the 1200XL? Have you tried the other menu select screen revisions?

Thanks for the quick reply.  I purchased this particular unit from eightbitfix.com.  My understanding is the only modifications done to it is enabling 5v on the SIO port, which I presume was done by shorting R63 on the board (seems to be the standard go-to procedure based on my research online), plus a new mylar for the keyboard.  Before he shipped the unit to me, he hooked it up to an official Atari Testing Station, and the only issue that came up was with the 6502, which he replaced, and afterwards all the tests, including the RAM, tested clear.

 

I don't have any testing software on hand to give it a thorough memory test, but if you can recommend perhaps an application for that purpose, preferably that could run off my MyIDE ][ cart since that seems to be working fine, I'd be glad to give it a try just to double check.  I hesitate to lay blame to the memory because I can run the game from the MyIDE cart, and it works perfectly fine there.  Seems like if it were a memory issue, the game would crash no matter where it's being loaded from, plus it seems that perhaps other games might also have issues loading.  I'm more than willing to investigate, however.

 

As for testing other menu selection revisions, I did attempt to try v3.0 on both SIO2SD devices (just the normal version, not the turbo one).  On the 800XL and XEGS, it works fine, but on the 1200XL, v3.0 locks up as soon as I attempt to enter a directory.

[_The Doctor__]

make sure the speed limiting caps are removed on the SIO port, on the 1200XL I think it's C90 and C91 .....  someone wanna verify my remembery?

 

Edited September 17, 2019 by _The Doctor__

[+DrVenkman]

44 minutes ago, _The Doctor__ said:

make sure the speed limiting caps are removed on the SIO port, on the 1200XL I think it's C90 and C91 .....  someone wanna verify my remembery?

 

“Speed limiting caps?” I’ve never pulled any caps out of the SIO signal chain on my 1200XL’s and they handle POKEY divisor 0 just fine as-is. 
 

[_The Doctor__]

Yes, and some people never had them on their 130XE's either but others did... depends on what your Atari came with.  That why asked...

[rockman_x_2002]

I'm at work, so I won't have a chance until later tonight to take a peek at the board itself.  However, I do have the "SIO High Speed" setting turned to "off" on both SIO2SD devices.  It was originally set at its default (hsindex = 6), and I wondered if that might be the cause for the 1200XL having the issues above, so I disabled that feature.  However, the same issue occurs.

 

But again, it seems to only be with Rescue on Fractalus!, plus the issues with the SIO2SD.XEX config tool that I mentioned.  For example, last night, I was able to load up two other Lucasfilm games just fine (Koronis Rift and Ballblazer).  It's a bit strange that Fractalus! is the only game that doesn't seem to like running on the 1200XL.

[+DrVenkman]

I’m betting the issue has more to do with the 1200XL OS than the computer hardware itself. Lucas titles use some funky loaders and don’t even usually run from the SIDE loader in the Ultimate 1MB, for instance. 

[rockman_x_2002]

29 minutes ago, DrVenkman said:

I’m betting the issue has more to do with the 1200XL OS than the computer hardware itself. Lucas titles use some funky loaders and don’t even usually run from the SIDE loader in the Ultimate 1MB, for instance. 

Ah.  Could be that then.  Any non-Lucas title I've thrown at it runs like a champ.  And heck, even other Lucas games work fine.  Just this single one.  Although, I would be curious then, if there's someone else out there that has a 1200XL with the 5v mod and an SIO2SD that could test trying to load the game.

 

Specifically, the disk image I've been attempting to run is the one from the Internet Archive, the disk-based 1985 Epyx release of the game.  https://archive.org/details/a8b_Rescue_on_Fractalus_1985_Epyx_US

 

However, I also have an R16 of the Atari 1987 XEGS cart release on my MyIDE ][.  Since it loads fine, that makes me wonder if it could well and truly be some kind of funky disk loading routine that Lucas did that just doesn't play nice with the 1200XL's OS.

 

Might that also be tested if I were to get hold of a real 1050 disk drive, copy the image to an actual disk, and attempt to load from it there?

Edited September 17, 2019 by rockman_x_2002

[+Nezgar]

9 hours ago, DrVenkman said:

I’m betting the issue has more to do with the 1200XL OS than the computer hardware itself. Lucas titles use some funky loaders and don’t even usually run from the SIDE loader in the Ultimate 1MB, for instance. 

I just ran the linked ATR from Archive.org through a few combinations in Altirra...

 

XL/XE OS Rev 3 OS = works

Altirra OS = works (!)

1200XL rev 11 OS = works

1200XL rev 10 OS = works..

 

All the above combinations were tried with accurate sector timing on and off...

 

Then enabled full drive emulation for a stock 1050, using 1200XL rev 10 and rev 11, also both worked...

 

Basically couldn't get it to fail. Not sure how the SIO2SD could break this...

 

To rule out the OS, maybe try booting an Atari Translator disk first, and see if any difference is seen booting Rescue on Fractalus? although that might be hard to switch the disk image..

[rockman_x_2002]

 

22 hours ago, Nezgar said:

To rule out the OS, maybe try booting an Atari Translator disk first, and see if any difference is seen booting Rescue on Fractalus? although that might be hard to switch the disk image..

 

Just now getting the opportunity to test our what you suggested, Nezgar, and it was an excellent suggestion.  I hadn't considered using the translator disk to rule out the stock OS itself as the culprit.  Unfortunately, the results weren't very conclusive at all.  I'm not sure if it's a result of loading off the SIO2SD or what.  But the procedure was to assign the Translator disk (both OS-A and OS-B) to D1, and Fractalus! to virtual drive V1.  I set the SIO2SD to boot straight to the Translator disk images (circumventing SIO2SD.XEX for the moment), and then pressed Shift + K3 on the device to swap out the "disk" to Fractalus!.

 

Unfortunately, neither Translator disk seemed to help at all, and in fact, the game wouldn't load for either.  In both cases, the Translator disk would load, and prompt for Fractalus!.  After switching to that disk, it would load up to $0008 and then stop loading, crashed on a black scree before the "Lucasfilm Games" logo.

 

Loading Fractalus! directly, I see the "Lucasfilm Games" logo, the intro animation, and title screen.  When I press either "Start" or "Option" (for demo mode), the game appears to start normally (the ship flies out of the bay and descends toward the planet).  But once the planet's mountain features begin to load, that's when the colors go a bit crazy, and after a moment or two, the game crashes outright.

 

I hesitate to call the tests conclusive, however, since this was done purely off an SIO2SD.  I don't have a real disk drive on hand to test with at this time, so I don't know if using an actual disk drive with a 5.25" floppy would make any difference.  But other software does appear to load fine, so it leads me to think that there's just some kind of incompatibility between the 1200XL, the SIO2SD, and perhaps the loading routines used for this particular game.

 

Also, I did pop the hood on the 1200XL to take a picture of the 5V mod that was done to it.  Attached is the picture of that, but it's basically just a straight wire where R63 was, as I've seen elsewhere online.  Seems fairly standard to me.

[phaeron]

The v3.5 version of SIO2SD.XEX still appears to have hardcoded internal OS addresses in it, so it's going to have problems with the 1200XL OS. What appears to work is still possibly going to run random code in the OS, which can then scramble OS variables to cause failures later on. For instance, one of the addresses jumped to by the configurator is a key click routine in the XL/XE OS, but in the middle of the line drawing routine in the 1200XL OS.

 

This is unfortunately something you'll have to deal with as a 1200XL owner, programmers that don't check or in some cases simply don't care if their software works on anything other than the XL/XE OS.

 

[rockman_x_2002]

5 minutes ago, phaeron said:

The v3.5 version of SIO2SD.XEX still appears to have hardcoded internal OS addresses in it, so it's going to have problems with the 1200XL OS. What appears to work is still possibly going to run random code in the OS, which can then scramble OS variables to cause failures later on. For instance, one of the addresses jumped to by the configurator is a key click routine in the XL/XE OS, but in the middle of the line drawing routine in the 1200XL OS.

 

This is unfortunately something you'll have to deal with as a 1200XL owner, programmers that don't check or in some cases simply don't care if their software works on anything other than the XL/XE OS.

 

That makes sense, phaeron.  I guess I was hoping against hope that what you said might not be the case, but it does sound like it's the nature of the beast when it comes to the 1200XL, unfortunately.  It would certainly explain why Fractalus! and SIO2SD.XEX are being a bit contrary with the machine.  But, since I can load the game properly using the MyIDE ][ (or so it seems), at least I'm still able to play it that way.

 

That being said, I've read where it's possible, with a bit of surgery and effort, to swap out the 1200XL's OS with the 800XL's, but since I have a fully working 800XL (and XEGS), I kinda hate to do that.  I want to try to keep the 1200XL as stock as possible (5V mod excepted).  So, is there any existing way to patch the existing OS's code via the MyIDE (or some similar cartridge or device) that could correct these issues, or am I basically just stuck having to work around them?  Or, better still, does there exist any kind of device similar to the Ultimate 1541 or EasyFlash 3 cartridges for the C64 that offers outright kernal replacement via the cartridge slot (doubtful as I'm sure the way Atari's cartridges work differs vastly from how the C64 does it, but it's worth asking just to clarify).

 

Likewise, would that also imply that even if I did have Fractalus! on a real floppy loading from a real 1050 drive, it might still fail to work, or might that correct the issue (i.e., the real problem being compatibility with how the SIO2SD works, and not necessarily the game)?  If that's the case, I might be willing to invest in a 1050 in good working order, a handful of floppies, and use the 800XL to transfer from SIO2SD to actual floppies and just play the games on the 1200XL from that.

 

I know it seems like a lot of trouble and effort for just one game, but it's really more about trying to understanding the true nature of compatibility between the 1200XL and SIO2SD.  It's starting to sound like even with the 5V mod in place, compatibility might still be a tad spotty at best.

[_The Doctor__]

Not all translator disks are the same.... which did you choose?

looks like all SIO caps are still in place also...

were all sio2sd on screen configurator versions tried?

were the results the same using just the sio2sd keys without using the on atari screen config?

 

Edited September 19, 2019 by _The Doctor__

[rockman_x_2002]

Just now, _The Doctor__ said:

Not all translator disks are the same.... which did you choose?

This is the translator disk I used:  http://www.atarimania.com/utility-atari-400-800-xl-xe-translator-_29943.html

[_The Doctor__]

Please try the FIXXL translate kit I've posted in another thread...

 

 

Edited September 19, 2019 by _The Doctor__

[rockman_x_2002]

18 minutes ago, _The Doctor__ said:

Please try the FIXXL or the translate kit I've posted in another thread...

 

 

I hunted down FIXXL and the translate kit.  FIXXL did the same as the other two Translator disks for me (loads to $0008 for Fractalus! and freezes there).

 

 

Also, to give answer to your remaining three points in the earlier post (sorry I missed those)...

 

24 minutes ago, _The Doctor__ said:

looks like all SIO caps are still in place also...

were all sio2sd on screen configurator versions tried?

were the results the same using just the sio2sd keys without using the on atari screen config?

 

Yes, it does appear that all original SIO caps are in place.

 

As for the screen configurator versions, I tried the following:

 

- Original v3.5:  Will load ATR images, but is excruciatingly slow when trying to switch directories, switch to loading the chosen disk (holding the X key), etc.  But does appear functional, albeit glitchy.

- Fixed v3.5:  Seems to work fine until you attempt to load an ATR image or boot into D1 (holding the X key).  Loading an ATR puts an "!" on the screen, while trying to boot a chosen disk restarts the machine, but there's a "k" in the upper-left, and the computer freezes up.

- v3.0:  Couldn't get this one to work at all on the 1200XL.

 

The results were the same, unfortunately, if I attempt to load disk images directly on the SIO2SD itself.  I tried this, and even turned off loading the configurator on startup (so it would boot straight into D1 on powerup instead).  The same issues occur with the game.

 

[_The Doctor__]

okay, but all this screen does is put items in the sio2sd slots, so you can power cycle and it should not leave anything in memory performing a fresh boot from the sio2sd...

 

the translator turns your Atari XL/XE into an 800 not an XL/XE!!      but- you can use the kit to create an XL/XE translator disk by stealing the XL/XE OS from one of your other xl/xe computers and use that on you 1200XL!!

 

I have posted a ROM OS to RAM OS in one of those threads, but I think it's in the kit as well....

 

You are looking to translate to an XL/XE OS not an 800 hence the kit... this is your best shot to do this without a soldering iron...

 

Edited September 19, 2019 by _The Doctor__

[Kyle22]

Try this to make it 100% compatiblw with 800XL.

 

Do the FIRST part of this, no need for the PBI, just the 800XL OS ROM and built in BASIC part.

 

When he says "All right ! Half way there." is where to STOP.

 

IIRC, BASIC is better in a 2764. Less hassle.

 

 

Read this: http://retrobits.net/atari/pbi.shtml

 

[rockman_x_2002]

It's been a long time but I thought I would update this thread with some progress.  I've fiddled with the 1200XL off and on over the course of nearly a year with no progress, software-wise.  After a few months on the shelf, I decided to take another look at the 1200XL and finally decided to do what I likely should've done in the first place:  I opened the sucker up and reseated every chip on the board.

 

I'm happy to report that the issue appears to have simply been a mis-seated RAM chip.  I'm now able to load Fractalus!, as well as use SIO2SD.XEX just fine on the machine, along with everything else I've thrown at it this evening.  Looks like the fix ended up being something very simple after all.