[HN Gopher] Recreating the lost SDK for a 42-year-old operating ...
___________________________________________________________________
Recreating the lost SDK for a 42-year-old operating system:
VisiCorp Visi On
Author : nkali
Score : 92 points
Date : 2025-12-04 10:25 UTC (3 days ago)
(HTM) web link (git.sr.ht)
(TXT) w3m dump (git.sr.ht)
| jdougan wrote:
| Wow, just what I wanted for Christmas. Back in the day I found
| VisiOn's approach fascinating since almost everything at the time
| was either more tightly integrated or completely unintegrated.
|
| Maybe someone could do the the old Reason software bus based
| system next? As detailed in Jan 1984 Byte magazine. Lord only
| knows if there are surviving copies anywhere in the world.
| msla wrote:
| It's interesting how this article deconstructs the buzzwords used
| in the marketing material to get from "VisiOn is a multitasking
| object-oriented OS using a VM to be portable" to "VisiOn is a DOS
| shell that uses C structs in a documented API and was never
| meaningfully portable"
|
| Seriously, the "VM" thing is stupid:
|
| > The term "virtual machine" used by VisiOn developers means
| something different from what we mean by the words "virtual
| machine" today. The closest word we use today would be "API".
| That's right, Visi On applications use a cross-platform API. Just
| like almost any other operating system today. I bet it was a
| really cool idea back in 1983, though.
|
| As if VM isn't overloaded enough already (quick: does it mean
| "Virtual Memory", "Virtual Machine" as in the JVM, or "Virtual
| Machine" as in Xen?) using it to mean "API" is just dishonest.
| jdougan wrote:
| The latter 2 usages are pretty much the same. They just have
| different virtual instruction sets.
| msla wrote:
| > The latter 2 usages are pretty much the same.
|
| Only if you ignore most of reality, sure.
| retrac wrote:
| Processes on modern operating systems are a type of virtual
| machine. On Linux or Windows, processes are provided with the
| illusion of infinite memory. And there is the illusion of
| infinite parallel threads of execution, bounded only by
| storage. That is a kind of virtualization, just not full
| machine virtualization.
|
| At the machine level the boundary between machine instructions
| and system calls and API becomes blurry. If you don't have a
| floating point unit, the instructions trap and a routine in the
| kernel can perform the same thing. Instruction sets are APIs.
| Many operating systems present their system calls as if they
| were special machine instructions.
|
| This kind of phrasing is less common today, where "virtual
| machine" is usually equivalent to "full machine
| virtualization", but you'll encounter this broader sense in
| earlier literature.
| bananaflag wrote:
| Also in this OS textbook
|
| https://pages.cs.wisc.edu/~remzi/OSTEP/
| msla wrote:
| > On Linux or Windows, processes are provided with the
| illusion of infinite memory.
|
| OK, how does this apply to what MS-DOS was doing? Remember
| that VisiOn is an MS-DOS shell.
| 01HNNWZ0MV43FF wrote:
| Yeah I remember an ad for an early x86 OS saying, "Each
| program here is running on a virtual 8086" and I was like
| "No... wait yes?".
|
| Virtual machines are such a cool idea that they just keep
| getting reinvented. You can solve any problem with more
| abstraction!
| dsand wrote:
| My partner Elaine Gord was on VisiOn's C compiler team in
| 1982-1984 with two others. They experimented with having two
| instruction sets: the native 8088 code for best performance, and
| a C virtual machine bytecode for code density. The two modes were
| mixed at the function level, and shared the same call/return
| stack mechanism. This was terrible for speed, but was thought
| necessary because the target machines did not have enough ram for
| the total VisiOn functionality. I don't know if the bytecode
| scheme got into "production".
| pdw wrote:
| All of Microsoft's applications used to do that! The 16-bit
| versions of Word, Excel, PowerPoint, etc all were implemented
| using bytecode. That technology was only integrated in
| Microsoft C and made public in 1992 [1], before that the
| Microsoft applications group used their own private C
| toolchain. A copy of it can be found in the Word 1.1 source
| release [2] ("csl").
|
| [1] https://sandsprite.com/vb-
| reversing/files/Microsoft%20P-Code... [2]
| https://github.com/danielcosta/MSWORD
| reactordev wrote:
| C was very much the _Javascript_ of its day. Hand rolling
| toolchains and compilers to the bytecode they knew and loved
| (or despised).
|
| This is awesome history. Formal history only remembers the
| what's, the when's, rarely does it catalog the why's, or
| how's. The decision making process of those early programmers
| helped shape a whole industry.
| classichasclass wrote:
| I think Multiplan for 8-bit systems was implemented in a
| similar fashion, which enabled it to be widely ported.
| cramcgrab wrote:
| Yep Mitch Kapor and the eff.
___________________________________________________________________
(page generated 2025-12-07 23:02 UTC)