• Please review our updated Terms and Rules here

Can DOS 2.11 work with XTIDE?

Torch

Experienced Member
Joined
Sep 7, 2018
Messages
158
Location
Indiana
My 1000EX works great with 6.22 and a 2GB CF; however, like back in the day, many games will not work with later versions of DOS. For example, Bubble Bobble has graphic glitches and freezes on the first screen. Playing with config.sys files and buffers helps, but the game will still crash after a few screens.
If I copy the game to a disk and boot with 2.11, it plays perfect.
2.11 that came with the EX always seemed to be the most efficient with memory. If I recall, 5.0 was also pretty good, but I don't have a boot disk for that. I do have 4.x but it's worse than 6.22.

So, is there a way to get Tandy 2.11 to recognize the xtide? I can boot off a floppy containing 4.x (using A or F8 at start) and C appears and works fine. C does not exist when booted with 2.11. I thought I'd be able to setup a CF card as a 32MB drive? Did Tandy leave out needed files?

Another option I'd like is 5.0, but I don't have it on disk. Has anyone devised a way to get a disk image onto the CF with a modern PC so it will autoboot? Normally I pop a new 2GB CF into my EX, boot 6.22 from a floppy, delete/recreate partition using FDISK and reformat and all is good. I can download images of 5.0, but I have no way to create a 360K floppy with them. I keep an '04 PC around that sort of transcends vintage to new, unfortunately its BIOS only supports 1.2mb 5¼ drives.
 
I don't think XTIDE is the problem. DOS 2.11 only supports FAT12. You need to use FDISK to create a FAT12 partition.
 
Your limited to 32MB Partitions as of DOS 3.3. So my advice is to get a smaller CF card if that is what you are using. I use 32 GB CF's on my XT and my Tandy 1000TX.
With DOS 2.11 your are limited to 16MB. Hope this helps.
 
Thanks for the suggestions. The 2gb cards are only $11 bucks on Amazon, so I don't mind if I'm only using 16mb of one for a limited number of games.

I'm mainly trying to figure out how to get DOS 2.11 to recognize there's a HD available. I have the factory 1000EX disks and there's no FDISK program on it.
I copied FDISK from 6.22 to a bootable 2.11 floppy and it just crashes the computer when I run it.

Does the official (not Tandy) MSDOS 2.11 have include FDISK?
 
It was pretty common for OEMs to not include FDISK as late as DOS 2.x because... reasons. There's a Tandy document for installing DOS on the original 1000 that references a program called "HFORMAT" that they bundled with their hard disk kit, not FDISK. According to this page you might not necessarily have good luck using a different FDISK; it says trying to use IBM's PC-DOS 2.1 to set up the disk resulted in a disk that could be read with Tandy 2.11 but not SYS'ed to boot from.

Trying to get 2.11 to boot of an XT-CF in either my EX or HX is a thing that's been vaguely on my list for a long time but, alas, I just haven't been able to be bothered. Although...

For example, Bubble Bobble has graphic glitches and freezes on the first screen. Playing with config.sys files and buffers helps, but the game will still crash after a few screens.

I noticed this issue with Bubble Bobble as well! It only seems to happen with the Tandy graphics mode, I've played pretty far into it set up with both CGA and EGA (My HX has a VGA card in it) and it's fine, but those Tandy-mode crashes were bothering me a lot. Verified they happened on both the HX and the EX, and I also saw them when I tried booting to Tandy DOS 3.3 instead of PC-DOS 7. I eventually gave up and concluded it must be some obscure incompatibility with my memory card configuration, XT-IDE BIOS, something. Now I guess I need to try running it after booting from a DOS 2.11 floppy...
 
Bubble Bobble also worked fine for me under CGA with 6.22. With 2.11 (and infinite lives) I played in TGA up to level 99 with no problems. I looked up the original box and it states it requires DOS 2.1 or higher and 512K for Tandy. You'd think 640K would be plenty with a higher DOS.

Commander Keen also has quite a few graphics glitches and tends to crash, but I'm not sure if the Tandy mode is still a work in progress or if it's also DOS issue. Unfortunately it won't fit on a 360K floppy, so I can't test it under 2.11. I need to set up a 3½ external drive one of these days.
 
Most of the issues I've had with Tandy-graphics stuff and DOS 5+ are probably fair to attribute to trying to use upper memory blocks. (As a for instance, the Tandy 4-color driver for Windows 2.1 crashes spectacularly with UMBs enabled.) Which makes some amount of sense because using Tandy graphics does clobber a memory structure DOS creates at the very end of memory when it adjusts the top-of-memory downwards from the normal 16K assigned to CGA graphics to MOAR for Tandy modes.

(Usually the only symptom is the commands in DOS to probe/load upper memory break; the drivers you loaded high are "fine", but Windows apparently spills its cookies all over the floor, probably because it does have some rudimentary understanding of memory over 640k being a thing.)

To test Bubble Bobble with 2.11 and Tandy graphics I'll either have to pull the VGA card out of my HX or get the EX down from the closet but, yeah, I'm curious now. Like I said, it still seemed flakey to me whether is was DOS 7 even with UMBs disabled or Tandy DOS 3.3. It bugged me because I could have swore I'd played it just fine like three years ago, but that may have been before I built my CF adapter and was just running it off the GoTek... which would have been either DOS 2.11 or 3.21.
 
For example, Bubble Bobble has graphic glitches and freezes on the first screen. Playing with config.sys files and buffers helps, but the game will still crash after a few screens.

How much RAM is in your EX? Bubble Bobble requires 512K free, Tandy graphics modes take up 32K of RAM, Tandy graphics modes use RAM from the lower 640K, and the later versions of DOS take up more RAM. If you have anything LESS than 640K in your Tandy system, you'll have a problem with that game with all of these factors combined.

Most of the issues I've had with Tandy-graphics stuff and DOS 5+ are probably fair to attribute to trying to use upper memory blocks.

There are no games that I know of that support Tandy graphics and also try to use upper memory blocks. Games that intentionally try to use UMBs are 386+/VGA era, and there are very few of them.

The more likely reason for the OP's troubles is simple memory exhaustion.
 
There are no games that I know of that support Tandy graphics and also try to use upper memory blocks. Games that intentionally try to use UMBs are 386+/VGA era, and there are very few of them.

I wasn’t referring to programs which themselves used or were aware of UMBs, it’s that some programs which use Tandy graphics when you have upper memory blocks enabled trigger crashes which appear to be the result of the BIOS top of memory being lowered (as is done to free up pages for use by the extended mode). There have been some threads in the past about how this breaks DOS’ memory management slightly. Most programs are “fine”, but my experience personally has been it’s better safe than sorry to reboot after exiting a Tandy graphics program before moving on to anything important. Like I said, though, Windows 2.1 crashes *hard* if you try using the Tandy graphics driver + UMBs.

And re: the Bubble Bobble problem, the bad behavior he’s mentioned I see with a full complement of memory expansion… and the same game runs fine for me on the same computer configured for CGA or EGA (if the card’s installed). Tandy sound can be mixed with either of those, again, works fine. And it *doesn’t* seem to have anything to do with UMBs, disabling them makes no difference.

I guess I should pull out the EX and see if I can replicate the “works fine with 2.11” results.
 
How much RAM is in your EX? Bubble Bobble requires 512K free, Tandy graphics modes take up 32K of RAM, Tandy graphics modes use RAM from the lower 640K, and the later versions of DOS take up more RAM. If you have anything LESS than 640K in your Tandy system, you'll have a problem with that game with all of these factors combined.

Full 640K using the original Plus board. In my original post, I mentioned 2.11 being more efficient with memory which is the reason why I want to get it working with my XTIDE setup.
I have a feeling that Commander Keen will also work fine with 2.11. A few times a pop up appeared saying memory was low so it's disabling Tandy sound. In a different level (probably using less memory) the Tandy sound would automatically come back.
 
Most of the issues I've had with Tandy-graphics stuff and DOS 5+ are probably fair to attribute to trying to use upper memory blocks. (As a for instance, the Tandy 4-color driver for Windows 2.1 crashes spectacularly with UMBs enabled.) Which makes some amount of sense because using Tandy graphics does clobber a memory structure DOS creates at the very end of memory when it adjusts the top-of-memory downwards from the normal 16K assigned to CGA graphics to MOAR for Tandy modes.

(Usually the only symptom is the commands in DOS to probe/load upper memory break; the drivers you loaded high are "fine", but Windows apparently spills its cookies all over the floor, probably because it does have some rudimentary understanding of memory over 640k being a thing.)

To test Bubble Bobble with 2.11 and Tandy graphics I'll either have to pull the VGA card out of my HX or get the EX down from the closet but, yeah, I'm curious now. Like I said, it still seemed flakey to me whether is was DOS 7 even with UMBs disabled or Tandy DOS 3.3. It bugged me because I could have swore I'd played it just fine like three years ago, but that may have been before I built my CF adapter and was just running it off the GoTek... which would have been either DOS 2.11 or 3.21.
where exactly does tandy graphics video memory reside in the UMA?
 
where exactly does tandy graphics video memory reside in the UMA?

(Explaining again…) It *doesn’t*. But to free up the memory at the end of the conventional 640k (which is of course never more than 624k on a 1000 because it by default has to reserve 16k for normal CGA graphics) it resets the BDA’s top of memory mark. And when the Tandy’s BIOS does this it breaks the DOS API that points to the UMBs.

And for the third time, most programs themselves don’t seem to have problems, but DOS itself can no longer see or enumerate anything in UMBs, including the drivers it loaded up there. (they will be invisible to “MEM”, you can’t LOADHIGH anything anymore, etc.) Once this link is clobbered by lowering the top of memory and using it for graphics it’s broken until you reboot.

My *guess* why Windows 2.1 is fine with UMB support disabled is that since it had at least rudimentary support for making use of high memory (It marked the introduction of himem.sys, etc, before they were included with DOS, for instance), which USE!UMBS partially emulates, this breakage bothers it. But heck if I know this is the exact reason.
 
Last edited:
(Explaining again…) It *doesn’t*.
It doesn't have CGA memory at B800? I'm not trying to be difficult here I just have no idea how Tandy graphics work

I follow what you're saying about adjusting the BDA memory field, but I'm trying to still understand why tandy does this
 
A “classic” Tandy 1000 (IE, the 8088s and most of the 8086 models) shares video memory with conventional memory in a single pool, IE, like a PCjr. (The memory mapping differs somewhat, but going into that is a Deep Cut...) So every byte used for video is subtracted from the conventional pool, in 16k chunks. With a less-than-SL 1000 by default BIOS maps a single 16k block for use by video at boot and sets the top of memory to the 624k mark, and that page is double-mapped at both 9C000 and B8000. Poke a “65” into 9C000 on a Tandy 1000 and you’ll get an “A” on your screen same as if you did at the proper CGA address.

(If you run Check-It or whatever on one of these machines they’ll never tell you they have 640k unless you disable Tandy video by plugging in a VGA card. In that situation the video page allocation is set to zero and DOS gets it all.)

So, yeah, they don’t have dedicated separate RAM for video; or it might be more precise to say that the last 128k or 256k (EX/HX) *is* video memory and it’s the CPU borrowing it. (That’s how it’s wired.) If they need more memory for video, either for a higher color mode or more pages, the BIOS top of memory gets moves down accordingly. And yeah, unfortunately this is not aware of the hooks DOS added around it when they extended the allocation system to understand upper memory so… breakage.
 
Full 640K using the original Plus board. In my original post, I mentioned 2.11 being more efficient with memory which is the reason why I want to get it working with my XTIDE setup.
I have a feeling that Commander Keen will also work fine with 2.11. A few times a pop up appeared saying memory was low so it's disabling Tandy sound. In a different level (probably using less memory) the Tandy sound would automatically come back.

It feels wrong to me that "low memory" has anything to do with the Bubble Bobble problem; the system requirements for the program were 512K and I've seen some references that this translates to 480K free; it's true that DOS 5+ (lacking any ability to load anything high) consumes about 50K more RAM than 2.11, but there should still be plenty of RAM to run it on a 640K system.

It is also interesting... and maybe a little bit of a relief, that you're seeing this problem with the original Plus board. I have a homemade board that doesn't have a DMA controller on it and I was getting down to theories that maybe the Tandy graphics driver in that program somehow relied on the DMA controller for... heck if I know.
 
Last edited:
this is the relevant part I wasn't understanding

Yeah, it's weird and somewhat complicated. The video chip actually has fairly sophisticated memory paging capabilities so if you do set up a mode that uses more than one 16K page or does page flipping the address in conventional memory that corresponds with the CGA address window will move.

And like I said, it's also different from the PCjr because the Jr's shared memory is fixed in the bottom 128K, which creates weird memory potholes for DOS to work around; the Tandy's hardware moves the shared memory to come *after* any expansion memory so video pages come off the top. It's cleaner and more compatible with regular PC memory management most of the time but it does have these unique incompatibilities with stuff that wants to live after the *end* of the normal DOS TPA, like these little linked list structures that UMB support sets up or certain BIOS extensions like the "Full Operating Mode" of the XTIDE BIOS. Tandy 1000-specific gotchas from the XTIDE docs.

Code:
* Full operating mode [default=No for XT builds, not available for AT builds]

"Full operating mode" reserves a bit of Conventional memory for XTIDE Universal BIOS variables. Disabling this will reduce the maximum
number of supported IDE controllers to 2 and place the variables in a memory area reserved for IBM ROM Basic (30:0h). You should always
enable this option unless:

  * You don't need to use IBM ROM Basic or any BIOS or software (e.g. Turbo BASIC, BASICA) that requires that memory area.
  * You have a Tandy 1000 with 640k or less RAM (see "kiB to steal from RAM" for a way around this problem).
  * You really need the 1 kiB of Conventional memory that "Full operating mode" requires.

* kiB to steal from RAM [default=1]

This menu item will appear only when "Full operating mode" is enabled. Leave it at the default unless you need to enable "Full operating mode"
on Tandy 1000 models with 640k or less RAM. Setting this to 33 (almost always enough) or 65 (always enough*) will reserve the top of RAM to
Tandy video circuitry in addition to the XTIDE Universal BIOS variables thus avoiding a conflict between the two.

I guess one way to test my theory about Windows getting bombed by the memory resizing would be to set the XT bios to Full Operating Modes with 33K or 65K of RAM pre-reserved so the top of memory shouldn't move when it starts? If that solved it and I *really* had some use for Windows 2.1 in four colors (which I don't)...

* Technically reserving 65K might not be enough, it is *possible* for a Tandy 1000 to use *all* 128K or 256K of RAM hanging off the video hardware for page flipping. I don't know that any useful software actually exists that reserves that much, but you could do it. Tandy 1000 BASIC may well limit you to 64K, though? (There's special syntax for the CLEAR command for setting aside video page reservation.)
 
Back
Top