5 ms·

This seems interesting, but I lack context. Can someone ELI5? Or maybe more like 'Explain Like I'm a CS Undergrad' (ELICSUG?).

by mabbo 5y ago

ableal 5y ago
In 1981 the VAX 11-780 was an object of lust for engineering undergrads, who'd be lured by faculty with promises of access to the "1 MIPS, 1 MB RAM beast" ... The author says he re-implemented the CPU (using Verilog) on an FPGA running at 50 MHz, well enough to run a test binary successfully.
- mabbo 5y ago
  Thanks!
rjsw 5y ago
Try this [1] [1] https://en.wikipedia.org/wiki/VAX https://en.wikipedia.org/wiki/VAX
lproven 5y ago
Um. Now I feel like I'm 106 instead of "just" 53. OK, so, basically all modern mass-market OSes of any significance derive in some way from 2 historical minicomputer families... from the same company. Minicomputers are what came after mainframes, before microcomputers. A microcomputer is a computer whose processor is a microchip: a single integrated circuit containing the whole processor. Before the first one was invented in 1974 (IIRC), processors were made from discrete logic: lots of little silicon chips. The main distinguishing feature of minicomputers from micros is that the early micros were single-user: one computer, one terminal, one user. No multitasking or anything. Minicomputers appeared in the 1960s and peaked in the 1970s, and cost just tens to hundreds of thousands of dollars, while mainframes cost millions and were usually leased. So minicomputers could be afforded by a company department, not an entire corporation... meaning that they were shared, by dozens of people. So, unlike the early micros, minis had multiuser support, multitasking, basic security and so on. The most significant minicomputer vendor was a company called DEC: Digital Equipment Corporation. DEC made multiple incompatible lines of minis, many called PDP-something -- some with 9-bit logic, some with 12-bit, 18-bit, or 36-bit logic. One of its early big hits was the 12-bit PDP-8. It ran multiple incompatible OSes, but one was called OS-8. This OS is long gone but it was the origin of a command-line interface with commands such as DIR, TYPE, DEL, REN and so on. It also had a filesystem with 6-letter names (all in caps) with semi-standardised 3-letter extension, such as README.TXT. This OS and its shell later inspired Digital Research's CP/M OS, the first industry-standard OS for 8-bit micros. CP/M was going to be the OS for the IBM PC but IBM got a cheaper deal from Microsoft for what was essentially a clean-room re-implementation of CP/M, called MS-DOS. So DEC's PDP-8 and OS-8 directly inspired the entire PC-compatible industry, the whole x86 computer industry. Another DEC mini was the 18-bit PDP-7. Like almost all DEC minis, this too ran multiple OSes, both from DEC and others. A 3rd-party OS hacked together as a skunkworks project on a disused spare PDP-7 at AT&T's research labs was UNIX. More or less at the same time as the computer industry gradually standardised on the 8-bit byte, DEC also made 16-bit and 32-bit machines. Among the 16-bit machines, the most commercially successful was the PDP-11. This is the machine that UNIX's creators first ported it to, and in the process, they rewrote it in a new language called C. The PDP-11 was a huge success so DEC was under commercial pressure to make an improved successor model. It did this by extending the 16-bit PDP-11 instruction set to 32 bits. For this machine, the engineer behind the most successful PDP-11 OS, called RSX-11, led a small team that developed a new, pre-emptive multitasking, multiuser OS with virtual memory, called VMS. VMX is still around: it was ported to DEC's Alpha, the first 64-bit RISC chip, and later to the Intel Itanium. Now it has been spun out from HP and is being ported to x86-64. But the VMS project leader, Dave Cutler, and his team, were headhunted from DEC by Microsoft. At this time, IBM and Microsoft had very acrimoniously fallen out over the failed OS/2 project. IBM kept the x86-32 version OS/2 for the 386, which it completed and sold as OS/2 2 (and later 2.1, 3, 4 and 4.5. It is still on sale today under the name Blue Lion from Arca Noae.) At Microsoft, Cutler and his team got given the very incomplete OS/2 version 3, a planned CPU-independent portable version. Cutler _et al_ finished this, porting it to the new Intel RISC chip, the i860. This was codenamed the "N-Ten". The resultant OS was initially called OS/2 NT, later renamed – due to the success of Windows 3 – as Windows NT. Its design owes as much to DEC VMS as it does to OS/2. Today, Windows NT is the basis of Windows 10 and 11. So the PDP-7, PDP-8 and PDP-11 directly influenced the development of CP/M, MS-DOS, OS/2, & Windows 1 through to Windows ME. A different line of PDPs directly led to UNIX and C. Meanwhile, the PDP-11's 32-bit successor directly influenced the design of Windows NT. When micros grew up and got to be 32-bit computers themselves, and vendors needed multitasking OSes with multiuser security, they turned back to 1970s mini OSes. This project is a FOSS re-implementation of the VAX CPU on an FPGA. It is at least the 3rd such project but the earlier ones were not FOSS and have been lost.
- jdhawk 5y ago
  ...slow clap... thank you for this.
- EamonnMR 5y ago
  I was not aware that NT shared OS/2 lineage.
  - acdha 5y ago
    There was even an OS/2 subsystem allowing you to run 16-bit OS/2 programs which wasn’t phased out until the Windows XP era. Almost nobody used it but there must have been some large customers insisting on it. https://en.wikipedia.org/wiki/Architecture_of_Windows_NT https://en.wikipedia.org/wiki/Architecture_of_Windows_NT
  - lproven 5y ago
    Oh yes. It was widely-known and acknowledged at the time but it's forgotten now. • OS/2 version 1.x: 80286, 16-bit, only a single DOS session. Cannot run Windows apps, but can run "family apps" -- binaries compiled to execute natively as DOS apps on DOS and OS/2 apps on OS/2. • OS/2 version 2.x: 80386, 32-bit, true DOS multitasking alongside OS/2 text-mode and Presentation Manager GUI multitasking. Can boot DOS in a VM, and also run a modified copy of Windows 3 inside a VM allowing 16-bit Windows apps to run on the OS/2 desktop alongside native OS/2 apps. Marketed as OS/2 v2.0, 2.1, and later as "Warp 3", "Warp 4" and "Warp Server". Licensed to 3rd parties as eComStation (from Mensys, a PDP-11 tools vendor) and later as Blue Lion. • OS/2 version 3: unfinished, planned to be CPU-independent, able run on various RISC chips (e.g. IBM POWER, SUN SPARC, MIPS etc.) as well as x86. OS/2 3 was substantially rewritten and completed by Cutler and team using a lot of VMS ideas, technologies and terminology as OS/2 NT, later Windows NT. NT for "New Technology" was a backronym. NT 3.1, 3.5 and 3.51 contained an "OS/2 subsystem" and were able to execute text-mode 16-bit OS/2 binaries natively. They could also format and read/write hard disk partitions in OS/2 HPFS format. NT 4 removed the ability to handle HPFS but the 3.51 SP5 HPFS driver could be installed and used to access HPFS partitions, but not create them. Windows 2000 removed the OS/2 subsystem completely. • IBM Workplace OS/2 for POWER: a largely unrelated OS, running on top of the same Mach microkernel used in Mac OS X, with an OS/2-compatible userland on top. Able to run 16-bit and 32-bit OS/2 x86 binaries under emulation as well as native POWER binaries.

This seems interesting, but I lack context. Can someone ELI5? Or maybe more like 'Explain Like I'm a CS Undergrad' (ELICSUG?).

by mabbo 5y ago

This seems interesting, but I lack context. Can someone ELI5? Or maybe more like 'Explain Like I'm a CS Undergrad' (ELICSUG?).

ableal 5y ago

In 1981 the VAX 11-780 was an object of lust for engineering undergrads, who'd be lured by faculty with promises of access to the "1 MIPS, 1 MB RAM beast" ... The author says he re-implemented the CPU (using Verilog) on an FPGA running at 50 MHz, well enough to run a test binary successfully.

mabbo 5y ago
Thanks!

rjsw 5y ago

Try this [1] [1] https://en.wikipedia.org/wiki/VAX https://en.wikipedia.org/wiki/VAX

lproven 5y ago

Um. Now I feel like I'm 106 instead of "just" 53. OK, so, basically all modern mass-market OSes of any significance derive in some way from 2 historical minicomputer families... from the same company. Minicomputers are what came after mainframes, before microcomputers. A microcomputer is a computer whose processor is a microchip: a single integrated circuit containing the whole processor. Before the first one was invented in 1974 (IIRC), processors were made from discrete logic: lots of little silicon chips. The main distinguishing feature of minicomputers from micros is that the early micros were single-user: one computer, one terminal, one user. No multitasking or anything. Minicomputers appeared in the 1960s and peaked in the 1970s, and cost just tens to hundreds of thousands of dollars, while mainframes cost millions and were usually leased. So minicomputers could be afforded by a company department, not an entire corporation... meaning that they were shared, by dozens of people. So, unlike the early micros, minis had multiuser support, multitasking, basic security and so on. The most significant minicomputer vendor was a company called DEC: Digital Equipment Corporation. DEC made multiple incompatible lines of minis, many called PDP-something -- some with 9-bit logic, some with 12-bit, 18-bit, or 36-bit logic. One of its early big hits was the 12-bit PDP-8. It ran multiple incompatible OSes, but one was called OS-8. This OS is long gone but it was the origin of a command-line interface with commands such as DIR, TYPE, DEL, REN and so on. It also had a filesystem with 6-letter names (all in caps) with semi-standardised 3-letter extension, such as README.TXT. This OS and its shell later inspired Digital Research's CP/M OS, the first industry-standard OS for 8-bit micros. CP/M was going to be the OS for the IBM PC but IBM got a cheaper deal from Microsoft for what was essentially a clean-room re-implementation of CP/M, called MS-DOS. So DEC's PDP-8 and OS-8 directly inspired the entire PC-compatible industry, the whole x86 computer industry. Another DEC mini was the 18-bit PDP-7. Like almost all DEC minis, this too ran multiple OSes, both from DEC and others. A 3rd-party OS hacked together as a skunkworks project on a disused spare PDP-7 at AT&T's research labs was UNIX. More or less at the same time as the computer industry gradually standardised on the 8-bit byte, DEC also made 16-bit and 32-bit machines. Among the 16-bit machines, the most commercially successful was the PDP-11. This is the machine that UNIX's creators first ported it to, and in the process, they rewrote it in a new language called C. The PDP-11 was a huge success so DEC was under commercial pressure to make an improved successor model. It did this by extending the 16-bit PDP-11 instruction set to 32 bits. For this machine, the engineer behind the most successful PDP-11 OS, called RSX-11, led a small team that developed a new, pre-emptive multitasking, multiuser OS with virtual memory, called VMS. VMX is still around: it was ported to DEC's Alpha, the first 64-bit RISC chip, and later to the Intel Itanium. Now it has been spun out from HP and is being ported to x86-64. But the VMS project leader, Dave Cutler, and his team, were headhunted from DEC by Microsoft. At this time, IBM and Microsoft had very acrimoniously fallen out over the failed OS/2 project. IBM kept the x86-32 version OS/2 for the 386, which it completed and sold as OS/2 2 (and later 2.1, 3, 4 and 4.5. It is still on sale today under the name Blue Lion from Arca Noae.) At Microsoft, Cutler and his team got given the very incomplete OS/2 version 3, a planned CPU-independent portable version. Cutler _et al_ finished this, porting it to the new Intel RISC chip, the i860. This was codenamed the "N-Ten". The resultant OS was initially called OS/2 NT, later renamed – due to the success of Windows 3 – as Windows NT. Its design owes as much to DEC VMS as it does to OS/2. Today, Windows NT is the basis of Windows 10 and 11. So the PDP-7, PDP-8 and PDP-11 directly influenced the development of CP/M, MS-DOS, OS/2, & Windows 1 through to Windows ME. A different line of PDPs directly led to UNIX and C. Meanwhile, the PDP-11's 32-bit successor directly influenced the design of Windows NT. When micros grew up and got to be 32-bit computers themselves, and vendors needed multitasking OSes with multiuser security, they turned back to 1970s mini OSes. This project is a FOSS re-implementation of the VAX CPU on an FPGA. It is at least the 3rd such project but the earlier ones were not FOSS and have been lost.

jdhawk 5y ago
...slow clap... thank you for this.
EamonnMR 5y ago
I was not aware that NT shared OS/2 lineage.
- acdha 5y ago
  There was even an OS/2 subsystem allowing you to run 16-bit OS/2 programs which wasn’t phased out until the Windows XP era. Almost nobody used it but there must have been some large customers insisting on it. https://en.wikipedia.org/wiki/Architecture_of_Windows_NT https://en.wikipedia.org/wiki/Architecture_of_Windows_NT
- lproven 5y ago
  Oh yes. It was widely-known and acknowledged at the time but it's forgotten now. • OS/2 version 1.x: 80286, 16-bit, only a single DOS session. Cannot run Windows apps, but can run "family apps" -- binaries compiled to execute natively as DOS apps on DOS and OS/2 apps on OS/2. • OS/2 version 2.x: 80386, 32-bit, true DOS multitasking alongside OS/2 text-mode and Presentation Manager GUI multitasking. Can boot DOS in a VM, and also run a modified copy of Windows 3 inside a VM allowing 16-bit Windows apps to run on the OS/2 desktop alongside native OS/2 apps. Marketed as OS/2 v2.0, 2.1, and later as "Warp 3", "Warp 4" and "Warp Server". Licensed to 3rd parties as eComStation (from Mensys, a PDP-11 tools vendor) and later as Blue Lion. • OS/2 version 3: unfinished, planned to be CPU-independent, able run on various RISC chips (e.g. IBM POWER, SUN SPARC, MIPS etc.) as well as x86. OS/2 3 was substantially rewritten and completed by Cutler and team using a lot of VMS ideas, technologies and terminology as OS/2 NT, later Windows NT. NT for "New Technology" was a backronym. NT 3.1, 3.5 and 3.51 contained an "OS/2 subsystem" and were able to execute text-mode 16-bit OS/2 binaries natively. They could also format and read/write hard disk partitions in OS/2 HPFS format. NT 4 removed the ability to handle HPFS but the 3.51 SP5 HPFS driver could be installed and used to access HPFS partitions, but not create them. Windows 2000 removed the OS/2 subsystem completely. • IBM Workplace OS/2 for POWER: a largely unrelated OS, running on top of the same Mach microkernel used in Mac OS X, with an OS/2-compatible userland on top. Able to run 16-bit and 32-bit OS/2 x86 binaries under emulation as well as native POWER binaries.