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Did somebody use, has or knows how to find a copy of an old DOS shell called "The OneDir" or 1DIR.COM by Bourbaki? I have a very old 5 1/4 floppy with it but don't know if it is even in good condition since I don't have working drives of that type.

There was a variation which supposedly was hacked and turned from an EXE to a COM, and I have been able to find some version with web searches but doesn't seem to want to install nor seemed to be the same version I had.

Does anybody know also if I could reliably read a 360K floppy with a 1.2MB drive?

Yes, that's the one I found, but I think it's a different version, it seems too new, doesn't seem to install (it should just run) and the one I had was from the 8088 era.

It was as old as a program named XTree, which I have attached so you can have idea of its age.

I think abandonware sites are your best hope. Vetusware contains many kinds of software. Other abandonware sites contain games mostly, so I don't think you will find it anywhere else on the web.

Why don't you code your own? Doesn't look like a difficult job... I've quickly looked over the 2 formats. Normally, you can't make .COM file out of any MZ executable unless it uses the tiny memory model but since no one uses 8080 CPUs anymore you are free to have a multiple-segment version of the .COM format...

No you aren't. COM cannot have more than one segment by virtue of the fact that is is a non-format: COM is just the splatting of the code and static data into a file. DOS loads the file to offet 0x100 in a segment and runs it. No headers, no way for >64kb files. COM is very close to a flat binary.

I meant he could invent his own -- I did specify that .COM files typically occupy only one segment because they were meant to run under the 8080 CPU which only had one segment. However, on 8086+ CPUs, a .COM file is free to manually change segments and still run correctly. His linker could inject code to change the segment everytime he messes with data or do a far jump to switch between code segments for instance (all of this is only possible for non-SMC code).

You'll have trouble running an x86 COM under an 8080 and vise versa. They're binary incompatible processors. But, yes, the COM format is a legacy of CP/M.

Nowhere does DOS or any other COM implementer say that you can't access other segments. The restriction is that your program's executable image may occupy only one.

While it would be possible to have code at the beginning of a COM file to apply a list of segment relocations like those in an MZ file, it would be pointless since the result would probably be larger than the corresponding MZ file.

Relocations? No relocations, PSP stays intact. My version .COM will run under DOS just fine, you won't need to modify the loader... The code itself contains "links" (JMP's and CALL's across segment boundaries). You don't care what those segments are in a monotasking environment (DOS). Under modern OSes, you have other techniques...

Love4Boobies wrote:Relocations? No relocations, PSP stays intact. My version .COM will run under DOS just fine, you won't need to modify the loader... The code itself contains "links" (JMP's and CALL's across segment boundaries). You don't care what those segments are in a monotasking environment (DOS). Under modern OSes, you have other techniques...

please note: dos is NOT entirely single tasking, and before using additional segments, you should ask dos if they are available and tell dos that you are going to use them... that way you dont overwrite (or get overwritten by) other tasks

dos is not single-tasking, its just more difficult to multi-task, and doesnt have an auto-multi-tasking user interface, it also doesnt have any hardware method of preventing programs from overwriting each other -- but it does have software methods, as long as all programs use them properly

Indeed. The average DOS system has multiple TSR (Terminate and stay resident) programs, providing drivers to the system.

more than just drivers... most power users in the old days, would run several programs which could pop up over your current program with a shortcut key, which would do various things... from scheduling programs, charts and databases, programing tools, spellcheckers, etc -- while these programs arnt truly running at the same time as your program, they are loaded in memory at the same time... of course that is in addition to the various parts of DOS -- which are not always in the same places (the DOS memory manager defines 2 types of DOS segments -- some can be freely trashed by applications, and will be reloaded from disk if they are needed -- as long as you inform DOS your doing so -- and others that cannot be touched, and should never be overwritten

in fact, even the typical user would often have trouble finding enough free conventional memory to load larger programs, which is why a lot of games would actually come with there own boot files (config/autoexec) so that they could be loaded without any of those other things in the way -- when you run it, it would reboot the system, using its own 'clean' files, then when it terminated, it would reboot again using your standard files

I think I managed to found the original 1DIR.COM at the Wayback Machine, and it has just been uploaded on June 16, 2015, although it looks like I need to extract it from a so-called "TeleDisk archive" to supposedly write it to a floppy or a virtual floppy disk image.


Description:
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https://archive.org/details/The1DIR


Program (it's packed in something called "TeleDisk" instead of ZIP, etc.):
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https://archive.org/download/The1DIR/THE1DIR.TD0

In ZIP: http://old-dos.ru/dl.php?id=12178