🚀 go-pugleaf

On 2018-07-15 21:00, Peter Flass wrote:
> Johnny Billquist <b...@softjar.se> wrote:
>> On 2018-07-15 12:17, Johnny Billquist wrote:
>>> On 2018-07-15 12:03, Huge wrote:
>>>> On 2018-07-15, Johnny Billquist <b...@softjar.se> wrote:
>>>>> On 2018-07-15 01:59, Bob Eager wrote:
>>>>>> On Sat, 14 Jul 2018 21:22:17 +0200, Johnny Billquist wrote:
>>>>>>
>>>>>>> Disk directly to buffers in user space in Linux? Sure, it's called
>>>>>>> mmap.
>>>>>>> Which, by the way, is more or less a direct ripoff from TOPS-20.
>>>>>>
>>>>>> Which was a ripoff from MULTICS and EMAS.
>>>>>
>>>>> I'm not sure about that. Multics, from what I read, considered memory
>>>>> and files to be the same thing. This is sort of a different idea than
>>>>> saying that you can map a file into a specific part of your memory. I
>>>>> have no idea how or what EMAS is. :-)
>>>>>
>>>>> But the comment about the ripoff goes as far as the Unix mmap API being
>>>>> pretty much a copy of TOPS-20.
>>>>
>>>> I find the word "ripoff" problematical. Virtually everything in computer
>>>> science is based on something else. Thinking "that's a good idea" and
>>>> re-using it in a new and interesting way is hardly "ripping off".
>>>
>>> If you take the concept *and* API and copy it verbatim, I think calling
>>> it a ripoff is not so wrong.
>>> Had they just taken the concept, then I'd say inspired by, or something
>>> similar. But this one goes a bit further. I remember back when Sun
>>> introduced mmap, that I heard (don't remember from where), that they had
>>> looked at TOPS-20 when they did the implementation for SunOS.
>>
>> I should probably modify my language.
>> For many, "verbatim" is probably hard to justify here. After all, the
>> TOPS-20 PMAP% system call is an API from assembly language, while the
>> Unix mmap() system call is an API from C.
> 
> Which, I believe, is just a wrapper for the corresponding Linux SYSCALL.

Oh, sure. But I guess it does appear different in the details from the 
TOPS-20 system call, so "verbatim" can be viewed as incorrect.
After all, the system calls in TOPS-20 places the arguments in AC1-AC4, 
while I think Linux places them on the stack, for example. But it's 
essentially only different at that level.

   Johnny

-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: b...@softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol