Path: ...!weretis.net!feeder9.news.weretis.net!i2pn.org!i2pn2.org!.POSTED!not-for-mail From: mitchalsup@aol.com (MitchAlsup1) Newsgroups: comp.arch Subject: Re: PDP-10 addressing, was The Design of Design Date: Sat, 27 Apr 2024 17:50:03 +0000 Organization: Rocksolid Light Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Info: i2pn2.org; logging-data="2548993"; mail-complaints-to="usenet@i2pn2.org"; posting-account="65wTazMNTleAJDh/pRqmKE7ADni/0wesT78+pyiDW8A"; User-Agent: Rocksolid Light X-Spam-Checker-Version: SpamAssassin 4.0.0 X-Rslight-Site: $2y$10$ApHTUJT0y/rgkukkplqU/uUtgNTXajmK2ijLQ1HINMPwSm91iOS1K X-Rslight-Posting-User: ac58ceb75ea22753186dae54d967fed894c3dce8 Bytes: 2391 Lines: 29 John Levine wrote: > According to Thomas Koenig : >>> While this wasn't terribly hard, it did mean that any time you wanted >>> to change a program to run in extended mode you had to look at all the >>> code and check every instruction that did an address calculation, >>> which was tedious. >> >>Hmm... would a simple recompilation have done the trick, or were there >>also issues with integers being restricted to 18 bits, for example? > This was 50 years ago. The system software was mostly written in > assembler. Some was written in BLISS which was more concise but still > extremely machine specific. BLISS reads a LOT like the original K&R C. > I suppose you could recompile your Fortran > programs, but the Fortran compiler was written in BLISS. > There were later versions of BLISS for the PDP=11, Vax and other > machines but they were not compatible with each other. Imagine if BLISS were machine independent ?!! > The earliest > places I can think of system programming languages with different > targets were when Bell Labs ported Unix to the Interdata, and the IBM > S/38 and its successors that had (still has) a virtual machine > language that is translated to whatever hardware it's running on.