[HN Gopher] What did the DOS "APPEND" command do?
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What did the DOS "APPEND" command do?
Author : SeenNotHeard
Score : 34 points
Date : 2024-12-20 21:04 UTC (1 hours ago)
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(TXT) w3m dump (www.os2museum.com)
| pavlov wrote:
| _> "In fact it is known that DOS 2.0 could not be built on PCs at
| all, and was built on DEC mainframes."_
|
| Nitpick, but DEC never made a mainframe. Their products like the
| PDP-11 were considered minicomputers (even though the CPU was the
| size of a fridge) to distinguish them from IBM's mainframes and
| medium sized computers.
| p_l wrote:
| The PDP-11 was minicomputer, but PDP-10s were "minis" only
| formally, with VAX due to reasonable size and comparable
| performance coining the title "supermini" IIRC.
| surgical_fire wrote:
| Nitpick, but as far as I remember, minicomputers _are_ midrange
| computers. DEC PDP-11 would be in the same class as IBM AS
| /400, so while they were distinguished from mainframes, they
| were "medium sized computers".
|
| Assuming, of course, that those "medium sized computers" are
| the midrange.
| retrac wrote:
| DEC was always finnicky about naming; the PDP series originally
| wasn't supposed to be called a computer because computers were
| thought of as much bigger than the products DEC sold, and
| customers in the 50s and 60s might be put off by a name they
| associated with multi-million dollar expenses.
|
| But the PDP-10 and VAX 9000 were basically mainframes. Million
| dollars or more. Whole large room with three phase power.
| Standard building AC might suffice but that was pushing the
| margin. And the faster clocked VAX 9000 was water cooled!
| That's not a minicomputer.
| mmooss wrote:
| > But the PDP-10 and VAX 9000 were basically mainframes.
| Million dollars or more. Whole large room with three phase
| power. Standard building AC might suffice but that was
| pushing the margin. And the faster clocked VAX 9000 was water
| cooled! That's not a minicomputer.
|
| Why is that not a minicomputer. From our perspective it's a
| massive installation; from the perspective of the time, it
| was not necessarily.
| varjag wrote:
| Minicomputer at the time was considered a system that fits
| in a rack or three. Not something that requires a purpose
| built room with own mains, raised floor and AC.
| mepian wrote:
| The PDP-10 was a mainframe:
| https://en.wikipedia.org/wiki/PDP-10#cite_note-1
| Hilift wrote:
| It was probably a VAX 11/780. If you were cheap you purchased
| an 11/750. The 780 had a PDP-8 for a console processor.
| https://news.microsoft.com/features/the-engineers-engineer-c...
| SunlitCat wrote:
| Another handy dos command, originating back to DOS is SUBST.
|
| Came in pretty handy when I wanted to share a folder with Remote
| Desktop, but it would only let me select whole drives.
|
| Made a SUBST drive letter for that folder, worked like a charm!
| bombcar wrote:
| IIRC originally SUBST was designed for that - early programs
| didn't understand directories but did understand drives, and so
| you could make a directory appear to be a drive and they'd be
| happy - otherwise they'd dump everything in the root of C:\ (or
| A:\\).
| mycall wrote:
| I still use SUBST with my team so we all have our source code
| on P:\ which can be mapped to wherever they want it to be. This
| helps keep Visual Studio object files and project includes
| pointing to the same place, especially when mistakes are made
| (they should be relative paths but things happen).
|
| It is run from a registry key upon bootup.
| Kwpolska wrote:
| SUBST is all fine, up until the point some tool explodes when
| it sees that normalizePath("P:\\\whatever") ==
| "C:\\\code\\\whatever", and it ends up with two paths to one
| file, or no way to build a relative path. I've seen that
| happen with some node tooling, for example.
| johng wrote:
| Ahh yes, subst was very handy many times back in the day and it
| worked like magic to me!
| technion wrote:
| SUBST to this day is how you solve long file name problems. One
| drive for business can make a very long path if it uses your
| full business name. Windows has the api to let some apps apps
| save long sob folders, but not to let Explorer or powershell
| delete those folders.
|
| You go on folder up and use subst to make a drive letter from
| which you can delete content.
| miohtama wrote:
| I remember wondering APPEND as a kid three decades ago. Looks
| like it had a very specific legacy use case, which was no longer
| present in more modern DOS versions. Live and learn.
| pram wrote:
| Is INT 2fH the DOS equivalent of PATH? What a bizarre mechanism,
| I've read it 2 times and I have no idea what it's saying lol:
|
| http://vitaly_filatov.tripod.com/ng/asm/asm_011.16.html
| epcoa wrote:
| It's sort of an ugly ass syscall extension mechanism (so it has
| no direct equivalent in Linux lets say), it definitely looks
| bizarre in modern times.
|
| Int 2F is initially handled by DOS, but additional programs
| (like drivers and TSRs) can override INT 2F, put their bucket
| of functionality and then fallback to the whatever the previous
| installed handler was (called chaining) for whatever they don't
| handle.
|
| This gives a glimpse into how much various crap could end up
| installed as an Int 2F handler:
| https://www.minuszerodegrees.net/websitecopies/Linux.old/doc...
|
| It was often used for feature/presence checks and usually
| nothing time critical as that chaining setup was most
| definitely not timing friendly.
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