[HN Gopher] The PDP-11 Basic Analysis Project
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The PDP-11 Basic Analysis Project
Author : elvis70
Score : 69 points
Date : 2021-08-08 11:34 UTC (11 hours ago)
(HTM) web link (www.learningpdp11.com)
(TXT) w3m dump (www.learningpdp11.com)
| RodgerTheGreat wrote:
| Moderators, consider capitalizing BASIC in the title for this
| article- it would make it more clear that it is referencing the
| language, whose name is an acronym.
| jhgb wrote:
| It wouldn't just make it "more clear" - it would also make the
| name correct.
| bsenftner wrote:
| Not sure why this is on HackerNews. PDP-11 Assembly was my first
| Assembly Language, taking a Harvard Summer School class it in
| when a high school student, maybe '82? If I'm remembering
| correctly PDP-11's instructions are augmented with an Assembly
| Macro System, Macro-11, providing an ability to create high level
| language structures and facilities. One of my big surprises in
| that class was the last two homework assignments: one took
| several previous assignments and combined them with the content
| of the new assignment, and we had a mini VI editor! The last one
| was similar, combining previous assignments, but this one used
| every assignment in the course, and when combined we had a C
| compiler. Blew my mind.
| rahen wrote:
| > Not sure why this is on HackerNews.
|
| This is the type of content I come to HN for. Nice tight code
| on well designed hardware, what's not to like?
| zh3 wrote:
| Somewhere I still have source for a PDP-11 bootloader I wrote
| back in the very early '80s. Managed to boot 2 or 3 different
| types of floppy and a HDD in a 256-word ROM, complete with
| command line interface. I vague recall a trick where I
| happened to have 102 in a register (from loading the bus
| event interrupt vector) and a free shift gave me 204 which
| was a sector read command for the FDC - that got me a crucial
| extra word saving I needed, to shrink it from 257 words to
| 256.
| bsenftner wrote:
| It just seems out of place; not like this is some old game
| console or hardware typically fondly remembered by the HN
| audience. That what I meant, all you down voting
| whippersnappers.
| implements wrote:
| I expect there's a fair few HNs readers with fond memories
| of using DEC equipment in their very early careers.
| fortyseven wrote:
| And there's those of us for whom these machines are well
| past our time... but we still enjoy reading about them
| and having appreciation.
|
| Frankly it's bizarre to me to think this isn't HN-
| relevant.
| rahen wrote:
| You would be surprised, I'm 37 and yet building a PDP-8 on
| a (large) CPLD, because I'm fascinated with this machine. I
| even considered building a DTL replica of the straight 8
| with PCBs and SMDs for a while, I have some R-series logic
| gates simulated in LTspice but this proved unpractical to
| build physically.
|
| I also have both a PiDP-11 with V6 UNIX and an IBM XT
| replica running ELKS, and I'm currently modeling the EDSAC
| (1949) in HDL. I find those machines fascinating, and the
| assembly code that came with them just as fascinating in
| resource efficiency.
| mattowen_uk wrote:
| "Not sure why this is on HackerNews."
|
| From the FAQ:
|
| _Anything that good hackers would find interesting. That
| includes more than hacking and startups. If you had to reduce
| it to a sentence, the answer might be: anything that gratifies
| one 's intellectual curiosity._
| wrs wrote:
| I'm happy to say not all HN readers think "classic hardware"
| means a Nintendo GameCube. :) There's quite a lot of interest
| in computing history around here (as it should be).
| cbm-vic-20 wrote:
| This is great! The PDP-11 instruction set is really nice,
| especially for its time. Lots of addressing modes make to easy to
| work with data in memory, especially compared to the
| microprocessor instruction sets that came out later in the 1970s.
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