ataylor284_

7 ms·

31.
by ataylor284_ 3y ago
Commodore had bought out MOS by this point and manufactured 6502 chips themselves, so the drive CPU was "free" in a sense. Also it's worth noting that the Commodore DOS talked about in the article was implemented and ran enti
32.
by ataylor284_ 3y ago
A better comparison would be the Motif/CDE GUI that commercial Unix workstations were using at the time on workstation-class hardware. I think NeXTSTEP still wins on style, particularly since X desktops were a garish mix of raw X, Xt
33.
by ataylor284_ 4y ago
The 8086 was designed to be a 16-bit 8080, and 16 times the address space of that chip was a nice incremental leap forward. If you didn't expect the chip to become the foundation of the PC industry for the next 4 decades, it was proba
34.
by ataylor284_ 4y ago
They're both called the "D" flag, and they both globally control the behavior of certain processor instructions. Besides that, they're totally different. The 8086 D flag is the direction for string instructions, whether
35.
by ataylor284_ 4y ago
Learned that one the hard way. I built a 6502 single board computer and tested it out running my customer built monitor. I spent hours verifying the hardware to isolate a problem where programs would crash and memory would become corrupted
36.
by ataylor284_ 4y ago
These 8086 instructions were pretty cool coming from a 6502 background. The usual way to copy a block of memory in 6502 was something like this: ldy #len loop: lda source-1,y ; memory accesses: loads opcode, address, value
37.
by ataylor284_ 4y ago
This blurs the real issue. You can still have different compensation and PIPs and everything else without stack rankings. The real issue is that stack rankings compel managers to meet a quota for low performers. Even if the team is full o
38.
by ataylor284_ 4y ago
As pointed out in another comment, it really is 4MB, since the segment register the memory is accessed through is exposed on the bus. You could include those extra 2 bits for a 22-bit total address space, although I don't think it&#x2
39.
by ataylor284_ 4y ago
I can see mapping CS to 1MB and DS, ES, and SS all to another 1MB for 2MB as moderately viable. This would make the system a Harvard Architecture instead of a von Neumann, with the escape hatch of segment prefixes. It would be even more of
40.
by ataylor284_ 4y ago
All the visualizations of the mandelbrot set I've seen use a threshold of iterations that define the edge. I think that threshold is more significant than any instability due to floating point numbers. A more formal analysis of numeric
41.
by ataylor284_ 4y ago
Very cool! I just finished a for-fun mandelbrot drawing program; I was familiar with the image, but I had never delved into the math. It's an extremely simple algorithm, which makes it that much more surprising it creates so much com
42.
by ataylor284_ 4y ago
The first computers DOS ran on were from a different era. The first PC model had 16kb of memory and a 160kb floppy drive. There was literally no space for error messages. DOS itself literally took up an entire disk. You'd have a DOS
43.
by ataylor284_ 4y ago
Not surprising. Back in the heyday of POSIX standardization, the Emacs camp and the POSIX camp were both very opinionated and not entirely aligned. One example is the standard disk block size used in command line utilities such as du and d
44.
by ataylor284_ 4y ago
4C is correct. My INT 21 function codes memory is a bit fuzzy.
45.
by ataylor284_ 4y ago
Yeah, segmented memory was such a headache. The large memory model that used "far" pointers broke some things that were taken for granted in C. Comparing pointers especially was an easy place to introduce difficult to find bugs.
46.
by ataylor284_ 4y ago
Ah, debug. I used debug extensively for machine code programming on DOS. I couldn't afford MASM and certainly didn't have access to free assemblers. My first hello world program was almost exactly this. However, I always ended
47.
by ataylor284_ 4y ago
I also tend to have important stuff in a buffer before doing anything destructive outside emacs although I definitely keep backup files on. Reminds me of a time a hard drive failed on a computer I had. I had an active ssh connection, runni
48.
by ataylor284_ 4y ago
When I started doing Java, everyone else was using JBuilder. Then Eclipse came along, and JBuilder died. Next, IDEA showed up, and Eclipse started to whither. Don't get me wrong, IDEA is great but IDEs do come and go, and are subjec
49.
by ataylor284_ 4y ago
The 65816 is a fascinating chip, even though it's a dead end in the evolution of home computing. It falls in a category with the Z8000 and maybe even the 80286: backwards compatible with their predecessors, but extending them in odd,
50.
by ataylor284_ 4y ago
The 8080 lacked this, but even though the 8086 was more or less based on the 8080, this probably inspired the 8086 LOOPNZ instruction. Same idea, hardcoded to use the CX register instead of B on the Z80. The unoffical nicknames for the AX
51.
by ataylor284_ 4y ago
A good chunk of Transactor is also available at https://archive.org/details/transactor-magazines , which does happen to be a huge database to store this kind of information. It's nice to see it available elsewhere
52.
by ataylor284_ 4y ago
A while back I did a demo and wanted a diagram to show what was going on. I stumbled on http://www.plantuml.com which did exactly what I wanted: it took mark up and turned it into an image that could be embedded in a github mar
53.
by ataylor284_ 5y ago
It remained unchanged for over 30 years, but there are actually two versions of the GIF file format. The second revision, known as 89a, added a few minor refinements like a frame rate for animations and transparency (but only binary, e.g.
54.
by ataylor284_ 5y ago
Very cool. One of the c64's glaring omissions for a hackable machine is a built-in monitor. My suggestion: throw a monitor program (my favorite: https://github.com/jblang/supermon64 ) onto the one of the disks and
55.
by ataylor284_ 5y ago
It's unfortunate that Commodore shipped BASIC 2.0 on the 64. They already had shipped PETs with the much superior BASIC 4.0 years earlier. It was likely a cost saving measure: they had a more favorable licensing deal with MS on BASIC
56.
by ataylor284_ 5y ago
CBM had 5 byte floats, but when they were copied into the floating point "registers", they were expanded into a 6 or 7 byte representation for speed. It was 8 bits of exponent, 1 bit sign, and 31 bits of mantissa (with one extra
57.
by ataylor284_ 10y ago
An upgrade card with a 20Mhz 65816 and 16MB RAM was actually sold as a product: https://en.wikipedia.org/wiki/SuperCPU , but it didn't really make anyone happy. The C64 purists stuck with the 6510 and those lookin
58.
by ataylor284_ 10y ago
I'm not following things as closely as I once did, but I think one of the main drivers was using gcc/clang for analysis, to e.g. make parse trees available inside emacs.
59.
by ataylor284_ 10y ago
The big change for this release is direct access to shared libraries. Traditionally, emacs has executed binaries directly for all its external interaction, using stdin and stdout for all communication. Now it will be able to call librarie
60.
by ataylor284_ 10y ago
Reimplemented, not ported. They wrote it from scratch, using innovative techniques to get the smooth side scrolling that was supported by hardware in consoles.

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