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Building GCC 1.27 (first GCC with x86 support) (2019)

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Re: Building GCC 1.27 (first GCC with x86 support) (2019)

#61

Post by fl7305 »

kjs3 wrote: post #51
fl7305 wrote: post #18

Earlier quoted context omitted.

A 750 wasn't very fast back in 1987 if I remember it correctly? But a 784 was still decent?

A 750 was a nice 'personal computer' in 1987 (I ran 3 of them in that year, along with a 780 and a bunch of different microVaxen/Vaxstations) especially if you had plenty of memory (8MB was comfy, 14MB max). CPU wasn't so fast (less than 1MIP), but I/O was well engineered and well matched so it 'felt' responsive. It was reasonably fast with 1 user, not terrible up to maybe 3-4 power users and significantly more just…

> You might be thinking of the 785

Yes, I wrote that wrong. I initially checked the VAX wikipedia page and thought 784 looked familiar. But I'm pretty sure it was a 785 now that you remind me.

> I/O was well engineered and well matched so it 'felt' responsive

Yeah, I remember back then how Dhrystones were pretty misleading when comparing things like a VAX 11/780 and a barebones 68000 system.

It was interesting working on VAXes. They had really good documentation (10 shelf-feet of orange binders :), and I liked the ";n" automatic file versioning. But having a personal Sun workstation with X11 was so much nicer, and Unix felt much more natural.

Re: Building GCC 1.27 (first GCC with x86 support) (2019)

#62

Post by kjs3 »

fl7305 wrote: post #60
kjs3 wrote: post #54

Earlier quoted context omitted.

Wasn't VAX assembly very orthogonal and nice? This is the stuff of religious wars; and the VAX is the patron saint of the CISC school of ISA design. Large parts of the VAX ISA are very nice, and it's a lot of fun to program in assembler. There's (relatively for the time) lots of registers, and tons of addressing modes. But some of it is plain bonkers. How many variations of ADDL3 are there across all addressing modes…

Yeah, I think I remember seeing the sysops load the VAX CPU microcode using a floppy on the front panel (?) I don't disagree in general. Writing a disassembler must have been a real challenge. It's a waste of gates in the CPU. You put a lot of unnecessary combinatorical logic on the critical path, which limits the clock speed. RISC chips remove everything that is not needed for the output of a C compiler, making the…

The 730 & 750 load microcode from cartridge tape (TU58). The 780/785 had a 'front end processor' (a baby PDP-11) which loaded microcode from floppies.

It's a waste of gates in the CPU.

Couple of things. First, VAX was designed when lots of stuff was still written in assembly, so they threw the kitchen sink at it. You didn't have a stdlib, you had huge numbers of assembly instructions. That wasn't how things evolved, but hindsight is 20-20, as they say. Second, C wasn't top-of-mind when designing VAX. The DEC systems programming language equivalent was BLISS, which is quite different than C. And FORTRAN & COBOL were probably more important.

And, yes, the folks who came up with RISC often cite the baroque nature of the VAX instruction set as inspiration for stripping things down. But there again, not driven by C per se; the first VLSI RISC, the IBM 801 (later PC RT), was targeted for a language called PL.8, a descendant of PL/I.

Re: Building GCC 1.27 (first GCC with x86 support) (2019)

#63

Post by kjs3 »

fl7305 wrote: post #61
kjs3 wrote: post #51

Earlier quoted context omitted.

A 750 was a nice 'personal computer' in 1987 (I ran 3 of them in that year, along with a 780 and a bunch of different microVaxen/Vaxstations) especially if you had plenty of memory (8MB was comfy, 14MB max). CPU wasn't so fast (less than 1MIP), but I/O was well engineered and well matched so it 'felt' responsive. It was reasonably fast with 1 user, not terrible up to maybe 3-4 power users and significantly more just…

> You might be thinking of the 785 Yes, I wrote that wrong. I initially checked the VAX wikipedia page and thought 784 looked familiar. But I'm pretty sure it was a 785 now that you remind me. > I/O was well engineered and well matched so it 'felt' responsive Yeah, I remember back then how Dhrystones were pretty misleading when comparing things like a VAX 11/780 and a barebones 68000 system. It was interesting workin…

Dhrystones were pretty misleading

Yeah...always good for a laugh. Sure, your 68k can compute a Sieve of Eratosthenes 3 times faster than my 780 (or whatever)...but no 68k alive (at the time) could support 50+ interactive terminal users like we did all day every day (and provide email, netnews, ftp, etc. for the whole campus).

DEC VMS is indeed very nice, but we didn't run it. We ran a locally hacked version of BSD 4.2/4.3. At some point I got upgraded to a Sun 3/160 on my desk (well...next to it) so I hear you.

Re: Building GCC 1.27 (first GCC with x86 support) (2019)

#64

Post by kjs3 »

pjmlp wrote: post #57
kjs3 wrote: post #52

Earlier quoted context omitted.

How many C++14 specific features will fit in 64k segments?

"Rich Code for Tiny Computers: A Simple Commodore 64 Game in C++17" https://www.youtube.com/watch?v=zBkNBP00wJE Followed by, "C++20 For The Commodore 64" https://www.youtube.com/watch?v=EIKAqcLxtT0

Frightening. :-)

Re: Building GCC 1.27 (first GCC with x86 support) (2019)

#65

Post by fl7305 »

kjs3 wrote: post #62
fl7305 wrote: post #60

Earlier quoted context omitted.

Yeah, I think I remember seeing the sysops load the VAX CPU microcode using a floppy on the front panel (?) I don't disagree in general. Writing a disassembler must have been a real challenge. It's a waste of gates in the CPU. You put a lot of unnecessary combinatorical logic on the critical path, which limits the clock speed. RISC chips remove everything that is not needed for the output of a C compiler, making the…

The 730 & 750 load microcode from cartridge tape (TU58). The 780/785 had a 'front end processor' (a baby PDP-11) which loaded microcode from floppies. It's a waste of gates in the CPU. Couple of things. First, VAX was designed when lots of stuff was still written in assembly, so they threw the kitchen sink at it. You didn't have a stdlib, you had huge numbers of assembly instructions. That wasn't how things evolved,…

Sorry, I didn't mean to sound disparaging. Given my specific use case of running compiled C code, then an advanced CISC CPU has a lot of wasted gates. But that's not what the VAX was designed for as you pointed out.

Re: Building GCC 1.27 (first GCC with x86 support) (2019)

#66

Post by I_am_uncreative »

kjs3 wrote: post #63
fl7305 wrote: post #61

Earlier quoted context omitted.

> You might be thinking of the 785 Yes, I wrote that wrong. I initially checked the VAX wikipedia page and thought 784 looked familiar. But I'm pretty sure it was a 785 now that you remind me. > I/O was well engineered and well matched so it 'felt' responsive Yeah, I remember back then how Dhrystones were pretty misleading when comparing things like a VAX 11/780 and a barebones 68000 system. It was interesting workin…

Dhrystones were pretty misleading Yeah...always good for a laugh. Sure, your 68k can compute a Sieve of Eratosthenes 3 times faster than my 780 (or whatever)...but no 68k alive (at the time) could support 50+ interactive terminal users like we did all day every day (and provide email, netnews, ftp, etc. for the whole campus). DEC VMS is indeed very nice, but we didn't run it. We ran a locally hacked version of BSD 4.…

It's hilarious how today we have a variant of this same argument with desktop vs. mobile CPUs.

Re: Building GCC 1.27 (first GCC with x86 support) (2019)

#67

Post by rahen »

anthk wrote: post #55
rahen wrote: post #46

Earlier quoted context omitted.

That exists, that's the TOAD2 from XKL. It apparently even runs TOPS-20. You can try one online at SDF, besides their SC-40 systems, which I think are also FPGA based. https://mastodon.sdf.org/@SDF/109824572356590874 Or you may want to get a PiDP-10, they will have an FPGA version soon to replace the RPI. https://retrocomputingforum.com/t/the-pidp-10-is-finally-don...

That's really cool. ITS with DNS and a faster CPU could do lots of 'modern' things such as maybe basic TLS and of course gopher would be a matter of spending a few months with Midas to create a client.

I would love to see such a great retro environment brought back to life on modern compatible hardware. ITS and Bliss in particular.

Re: Building GCC 1.27 (first GCC with x86 support) (2019)

#68

Post by fl7305 »

kjs3 wrote: post #63
fl7305 wrote: post #61

Earlier quoted context omitted.

> You might be thinking of the 785 Yes, I wrote that wrong. I initially checked the VAX wikipedia page and thought 784 looked familiar. But I'm pretty sure it was a 785 now that you remind me. > I/O was well engineered and well matched so it 'felt' responsive Yeah, I remember back then how Dhrystones were pretty misleading when comparing things like a VAX 11/780 and a barebones 68000 system. It was interesting workin…

Dhrystones were pretty misleading Yeah...always good for a laugh. Sure, your 68k can compute a Sieve of Eratosthenes 3 times faster than my 780 (or whatever)...but no 68k alive (at the time) could support 50+ interactive terminal users like we did all day every day (and provide email, netnews, ftp, etc. for the whole campus). DEC VMS is indeed very nice, but we didn't run it. We ran a locally hacked version of BSD 4.…

> At some point I got upgraded to a Sun 3/160 on my desk

I was going to say that it was a nice thing to have fall into your lap, but considering that it weighed 100 kg, maybe not.

I got started with a Sun 3/50 when it was a few years old. It was slow, but surprisingly usable as an X11 development machine for C programming.

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