37

UCSD Pascal was a product of UCSD - The University of California at San Diego. It was not a product of Apple. UCSD Pascal was available on a number of machines, including the PDP-11, TI99/4, the BBC Micro and the IBM PC. It was a noble attempt to produce a fully cross-platform language. UCSD Pascal used a disk filing system that was intended to be ...


32

You should be able to use the Amiga hard drive directly on your Linux computer (provided it still has IDE support). Linux also understands AFFS (Amiga Fast File systems), at least once AFFS support is compiled into the kernel (from your "self customized" wording I would assume you know how to do that). Apparently, some Linux tools don't seem to understand ...


29

It simply makes sense to have a symbol that stands for the current directory. It makes sense for the symbol to be easy to type and to stand out from ordinary directory names. Dot is a pretty good choice. It makes learning a lot easier if the same symbol means the same thing in multiple contexts. consider the following: chdir .\subdir copy c:\test\*.* . ...


28

I remember CDD as a 4DOS command, which would have been available in the Norton Utilities as NDOS. JP Software’s other shells also implement CDD, so 4OS2 and 4NT users would probably recognise it too. There is at least one batch file implementation of CDD too, developed by Gary Mays in 1996, and provided as part of his “M” batch file enhancer (which I can’t ...


24

UCSD Pascal was developed prior to the Apple II, during the 70's in San Diego, using PDP-11 class machines with a 512-byte block disk structure. In the process of porting it to microcomputers, often (not always) the file system also got ported. UCSD Pascal was seen as a closed environment offering everything in one place. Today we might call this an IDE ...


19

PC/MS-DOS 1 used the slash (/) as the command line switch indicator (like DEC's RSX11 and DG's RTOS before), so when DOS 2.0 introduced subdirectories, they did need a new one. Backslash (\) came somewhat natural - at least on US keyboards. With 2.0 IBM/Microsoft also tried to reverse that decision and introduce a syscall (INT 21h function 3700h and 3701h) ...


17

The whole CP/M family of operating systems, until Concurrent DOS, had both a limited number of files per drive and no hierarchy except for user areas. From the Wikipedia article: CP/M 2.2 had no subdirectories in the file structure, but provided 16 numbered user areas to organize files on a disk. To change user one had to simply type "User X" at the ...


17

Most early microcomputer operating systems were single-level - Apple DOS, CP/M, MS-DOS/PC-DOS prior to version 2.0, UCSD P-System, whatever Commodore called their DOS for the PET/CBM and C64. With the exception of UCSD P-System, which had a maximum of 77 files in the directory, I don't believe any of them had an inherent limit to the number of files, but ...


16

There are quite a few differences between the MS-DOS CHKDSK and ScanDisk, beyond the latter’s friendlier interface. ScanDisk can “repair” cross-linked files, i.e. files which end up pointing (entirely or partially) at the same cluster chain — this always involves data loss, but it’s better than CHKDSK which would only tell the user about the problem (users ...


14

Documents such as this expand slightly on the attribution of 19h to Willowtech Photon COS with: Code 19H is Claimed for Willowtech Photon COS by Willow Schlanger. So Willowtech was either an individual or a company named after its founder. Willow Schlanger is named as a contributor to Ralf Brown's Interrupt List in 1997, which is the oldest source that ...


13

CHDIR . is a bit confusing since CHDIR produces the exact same result and both in fact are pretty much a no-op. Not really, not even at first sight, as (under MS-DOS) chdir prints out the current directory, while chdir . does not. Of course, this may vary depending on the OS in use. For example under Unix, neither cd . nor cd produce anything but a linefeed....


11

In addition to the examples already given a couple more used a flat data structure with an absolute limit on the number of files but one property assigned to each file was its directory. So the real storage was single level — a single data structure, with file names being required to be unique across the entire disk — but it was presented as if a single ...


10

Yes. Several. Consider, for example Dec RSTS/E. This was a flat directory structure. Now, to be clear, the system had separate accounts. So, each user would have their own account/directory. Very similar to Users in CP/M. But they weren't hierarchical. As for RSTS/E file capacity, I don't know the specifics, but I'm sure it had a limit of the total number ...


10

Another use of the dot that I think has not been mentioned is that it allows you to specify what executable to use and tells the OS to not search the PATH. If I type (DOS or Unix) pdflatex then the OS will search for an executable named like that, starting with the current directory and then those listed in the PATH variable. But if you type (in DOS; ...


8

The (at least original DOS versions of) chkdsk checked the integrity of the FAT filesystem. Say, a reboot occurred interrupting a disk write, chkdsk e.g. could find correspondingly corrupted files and clean up. scandisk, on the other hand, could also perform tests of the physical disk surface by performing read and write operations, and it could identify bad ...


8

Why did Commodore files not include metadata to say where in memory to load it? They are there. Every saved memory content starts with two bytes noting the address it's taken from. No matter if disk or tape, if BASIC or machine code. But since it doesn't really make sense to save a file in one way and load it again the other way, then the user needs to ...


7

Does 'single level' mean exactly one directory a la early DOS floppies, i.e., no directories other than the root? Or does it mean multiple directories, no nesting, except maybe of user directories in the root directory? So you have directories /foo and /bar, and we can overlook the fact that there's actually a directory called / which contains foo and ...


7

ToolShed seems to be the current maintained OS9/descendants disk manager tool. It's not a file browser but works on the command line. Are you sure your disk image is a valid RBF image, though? Toolshed refuses to read it: $ os9 dir os9000-xibase.img dir: error 216 opening 'os9000-xibase.img,' dir: error 216 opening 'os9000-xibase.img' Similarly, checking ...


6

The codes in question were normally used to simulate special interrupts and/or control cards. The idea is that you could take a stack of 80-column punch cards (for instance) and translate them as a series of 80-column lines in a single ASCII file. To indicate a separator card, you'd put in a RS.


6

The IMG.* files contains all textures and sprites in uncompressed/unencrypted state so its very easy to render, but there is no VGA palette there (nor in other files you posted). I found this: Nightmare3D DOS Archive and inside the game zip I found GAME.PAL file containing the palette ... Its 1924 Bytes long and its look like the palette for IMG.* sprites ...


5

DOSLFN is the smallest LFN driver I’m aware of, short of built-in support in operating systems — but kernels with LFN support built-in take more memory than DOS 5. DOSLFN itself only needs 12K of memory. Since you’re trying this on an Omnibook, changing the operating system isn’t trivial anyway. The symptoms you show suggest that Emacs is failing to start ...


5

There is no specific 'format' required. On a real PDP-11, what happens at bootup depends on what kind of boot PROM you have installed. In general, for disk-type devices the convention is to load the first block then jump to the code in that block. If you don't have a boot PROM for the device you want to boot from, you may have to toggle in a bootloader ...


5

which allowed the user to choose freely between 3rd party applications in opening data files. and (from a comment) I was under the impression that early PCs bundled their own applications (like word processor or spreadsheet program) without any means to have another application be used in its place (or documented means?). Was this the case? If so, what ...


5

My hypothesis is as follows: The last time you successfully formatted the drive to be bootable, you did it with something that only understands FAT16 booting, so it installed a boot sector that only knows how to hand off to FAT16 partitions. When you formatted for FAT32, you didn't properly ask for a bootable FAT32 partition, so you've got a boot sector ...


4

I think it should go something like this. (I don't know where I can find a ROM image that'll load into an online emulator to check.) You can check which ROMS are in which bank. *ROMS ADFS should be in bank D (i.e. 13). *UNPLUG 13 *ROMS That should now show that ADFS is unplugged. Load your image into one of the sideways RAM banks 4, 5, 6, or 7 (...


4

Both tape and disk formats include the start address of the file. Tape formats, but not disk formats, also include a flag to force the file to be loaded at the address indicated on the tape regardless of the command used to load it, while disk formats did not. When loading a BASIC program, it is generally desirable to have it load at the start of BASIC ...


4

The README.txt file in the MS-DOS 2.0 source code, which was apparently intended to guide OEMs on how to build custom DOS builds for their hardware, indicates that the decision to use backslash was requested by IBM: Microsoft had been originally intending to use forward slash, and the change happened late in the development process. This is probably why the ...


4

At least in MS-DOS, when a new directory is created, it is first populated with two special entries, .. which points to parent directory where it was created from, and . which points to itself. It is possible that being currently in some directory just means keeping a pointer to a directory, and absolute path name can be get by just following the .. entries ...


4

The . entry exists in MS-DOS because it was copied from Unix. In Unix, it serves the purpose of supplying a name to the current working directory. If we want to traverse the current working directory, we need to pass something to the opendir function: DIR *d = opendir("."); The dot is also useful for executing programs that are in a relative path. For ...


3

I'm not sure about the PET or VIC20, but the C64, C128, C128D, Plus/4, C16, and related machines used a ROM OS, rather than a DOS. That said, they all used basically the same flat disk format, with a limit of 144 files per directory. With the 1541, there were a total of 664 blocks per side of a disk, but one could only access one side at a time. With the ...


Only top voted, non community-wiki answers of a minimum length are eligible