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13

What are the differences between these? I'm not that interested in architectural differences, cache sizes, etc. I'm most interested in the differences that could feasibly trip up an assembly language programmer. TL;DR: No. For user side assembly programmers next to none - at least until the KL. UUOs (*1) did hide add ons for backward compatibility or non ...


11

From the MIT AI Lab file .INFO.; LISP ARCHIV for Maclisp updates: 3/1/69 JONL THE CURRENT VERSION OF LISP, "LISP 102", HAS THE FOLLOWING AS-YET UNDOCUMENTED FEATURES: 1)"DEFUN" IS AN FSUBR USED TO DEFINE FUNCTIONS. EXAMPLES ARE (DEFUN ONECONS (X) (CONS 1 X)) WHICH IS EQUIVALENT TO (DEFPROP ONECONS (LAMBDA (X) (CONS ...


8

This is a frame from MIT AI film #43. I'm not sure what year it's from, but it seems to be from the PDP-6 era. The code is very similar to old ITS source code, so it's likely this is a tiny fragment of PDP-6 ITS. The use of "↓₁₄" identifies this as text displayed by PDP-6 TECO. Transcription, including a few more lines visible in the film: LDB B,...


7

I think you need to keep the context in mind to understand the decision. The PDP-6 was introduced in 1964. At the time, the number of high level languages in wide use could be counted on one hand with fingers left over. In fact, they were pretty much: Fortran, COBOL, and Algol. Just about the only other obvious candidates would have been LISP and CPL. LISP ...


6

It's not that FORTRAN required those particular instructions, but that they were the sort of instructions that existing FORTRANs tended to use. At the time, calling conventions were somewhat unsettled, and different machines exhibited a fairly large variety of instructions to implement calls. The link you gave cites the ostensible reason: JSA, Jump and Save ...


6

This is only a partial answer, and I hesitate to post it because it's going to primarily be a link, but... There are some real, programmer-visible differences between the PDP-6 and the KA10, though for the most part the KA10 can run code intended for the PDP-6. Here is a pretty comprehensive list of differences - there are just too many to copy into a ...


6

Bitsavers has some PDFs of printouts of tsExec1.4. Not sure if this is complete. There's a lot of PDP-10 software e.g. at trailing-edge, I suppose at least some of that could be adapted to run on the PDP-6 (but you probably already thought of that).


4

The program was MAC HACK VI. This link doesn't give access to the program, but it may give you some leads about where to find it. It was a chess playing program, and a good one for its time frame. https://chessprogramming.wikispaces.com/Mac+Hack Also, here's a link to pdp- TECO. The best text editor around in 1965. This link does have a Download button,...


4

Old versions of the Monitor: http://pdp-6.trailing-edge.com/ PDP-6 notes from ITS, includes some PDP-6 programs: https://github.com/PDP-10/its/issues/278


4

For the assembly language programmer, perhaps a KS10 acted like a KL-10 Model B (except for I/O, as mentioned), but FWIW the KS10 was a completely new CPU implementation using 10 of the AMD 2901 bit slices. (Two bits were hanging off each end, so that the half-word boundary was between chips.) The microinstruction sequencer was custom. It used Unibus ...


3

The defun macro is just syntactic sugar for define plus lambda. InterLisp (1970) doesn't seem to have it either, so your MacLisp example is either the first, or pretty close to being the first.


3

A significant chunk of PDP-6 software has surfaced: JOSS. https://www.rand.org/pubs/research_memoranda/RM5437.html It's being typed in: https://github.com/PDP-10/joss-36


3

Update. There is now quite a bit of PDP-6 software, but almost all of it from MIT: Monitor from DEC. SYSTEM GEN, low level DECtape formatting. MACDMP, file system on DECtapes. DDT, debugger. TECO, editor. MIDAS, assembler. STINK, linker. LISP. Spacewar! LIFE. MacHack VI... we have a timesharing version, unsure if it runs standalone on a PDP-6. David Silver'...


3

A DECtape labelled TS9 has been round in Richard Greenblatt's house. Given other labels found in the RG; FD 4/1/68 file, it's likely it would have a copy of PDP-6 ITS. EDIT. The tape has been imaged and analyzed. There are files from ITS, but not ITS itself.


3

Another piece of tantalizing evidence has surfaced. It's an old ITS file called RG; FD 4/1/68. The name obviously suggests a dating, and it's before a pager was installed. The file contents are listings from DECtapes. The files listed include LISP, DDT, TECO, MIDAS, and ITS versions in the three hundreds.


2

Here's another clue. It seems Gerald Sussman had (has?) a printout of ITS from 1967. The[n] he pulled out a printout that he handled as if it were an original Gutenberg bible. It was the original code for the ITS operating system — the Incompatible Timesharing system. It even seemed awesome to me. Today we just accept the fact that a mainframe computer can ...


2

For a long while there circulated rumors there used to be a 36-bit computer called the PDP-3. According to legend, DEC made a paper design but never built it themselves. Supposedly one customer took the design and built it. Information from Wikipedia is that the customer was "Scientific Engineering Institute" which was actually a front for CIA. The paper ...


1

(Just a Remark about the being 'modern' or not) It's quite a strange subroutine calling mechanism, as well. The PC is not stored on the stack, like most modern subroutine calling conventions, nor is the PC stored in the first word of the subroutine, like on some other PDP's. Not really, it's a variant of Branch and Link like used not only in very old ...


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