jrdres

tháng trướcdiscuss

Chinese apparently was originally always written vertically top-to-bottom. (And then columns would be right-to-left.) Modern Chinese just rotates everything except the characters themselves 90 degrees to the Latin order.

I also read that a few Chinese texts only make sense in vertical order: one had a pun where the characters read one way as separated characters, but as stacked was also a single character pun for something like a "crumbly cookie".

jrdres

tháng trướcdiscuss

Believe it or not, there once was an 8-bit computer with native Arabic. It was a version of the Z-80 MSX series by Al Alamiah called Sakhr. It seems it could switch between English, Arabic, or mixed. (In fact, this was mentioned in the OP.)

I'm curious how it handled mixed entry.

https://forum.vcfed.org/index.php?threads/bought-a-al-alamia...

https://www.msx.org/wiki/Sakhr_AX-230

jrdres

2 tháng trướcdiscuss

A forgotten point is that modern pixel fonts all assume pixels have a 1:1 ratio: height the same as width, so an 8x8 character box is perfectly square.

That's NOT true for many of the old computer displays. Most had finer resolution in the horizontal compared to vertical lines, so more pixels across than in the same distance down. 1:1 "square pixels" was an innovation of the Macintosh, and very unusual for the time. So the fonts on this page displayed on other 80's machines would not look "right". And fonts from those machines brought to modern displays also look off.

jrdres

2 tháng trướcdiscuss

Interesting. In the 70's & 80's, 8-bit microcomputers had a the same problem as old teletypes: you couldn't type in some ASCII characters even when the computer could display them. (And many couldn't.) At least some home-grown tiny-C compilers allowed a Pascal-like "BEGIN" and "END" substitute, which I'm sure would be an abomination to Kernighan. Even Pascal itself could have a problem: the very popular TRS-80 Tiny Pascal used ( and ) instead of [ ] for arrays because neither brackets nor braces could be typed.

To summarize from the article for { and }:

Modern digraphs:

   <%  ,  %>. This is only one that looks symmetric

Less-modern trigraphs:

  ??<  ,  ??>

Unix v4 (in the teletype driver):

   \(  ,  \)

PDP-11 B:

   *(  ,  *)

PDP-7 B:

   $(  ,  $)

In other micro software (Advanced MuMath for the TRS-80), I have seen:

   <<  ,  >>    for [ , ]

   (<  ,  >)    for { , }

Back in the 80's, the joke among new learners of C and Unix is that the designers must have had a very bad keyboard where typing each character was painful, because every keyword or command was so short and cryptic. This article suggests a different reason: on their 36-bit Honeywell 6070, "four characters fit into a word", so there was incentive to fit in 1 machine word.

It also explains why they used the obscure characters {,},|, and ~ while never using the FAR more common # and @. In the Teletype driver, "#" is clear previous char, and "@" is clear current line. So unavailable for C. I will still curse the C designers to my dying day for picking * as the prefix operator for dereference pointer, when the more logical @ character was SITTING RIGHT THERE! On every keyboard! So now every newbie to C has to stop thinking "multiplication" when they see *.

jrdres

3 tháng trướcdiscuss

Huh. Works on Android phone. Doesn't work on desktop, Adblock or no Adblock.

jrdres

3 tháng trướcdiscuss

I'm confused. Should I be seeing something on this site?

From the comments, there are apparently supposed to be amazing photos. But I see text, I see black backgrounds, but no photos--none at all. Neither on Firefox, nor on Chrome. Just empty boxes where say "Amber Ducky" should be.

jrdres

4 tháng trướcdiscuss

The CBS field-sequential color system did have one application after the 1950's: it was the system used for color transmissions from the Apollo moon landings.

https://en.wikipedia.org/wiki/Apollo_TV_camera#Westinghouse_...

If you watch footage of the Apollo 17 LEM liftoff from the moon, you can see color artifacts in the burst of fragments off the platform. Their motion is too fast to stay in the same color band.

jrdres

6 tháng trướcdiscuss

It runs, but it would be very slow on actual hardware.

I tried on a cycle-accurate emulator of a TRS-80 Model I with Omikron CP/M mapper. Most Z-80 machines of the time were 4MHz, but the TRS-80 was only 1.77 MHz.

1. Type "GUESS", get question prompt.

2. User types: "Are you an animal?", ENTER key

3. Wait 25 seconds

4. Program prints "N"

5. Wait 20 seconds

6. Program prints "O"

7. Wait 23 seconds

8. Program prints linefeed, returns to question prompt

Total time to return 2-char answer to user's question: 1 min 9 sec or so. I bet a longer answer would take proportionally longer.

"The wonder isn't that it does it well, it's a wonder it does it at all."

jrdres

năm ngoáidiscuss

Thanks for the 8088 version on Github. Any chance you still have the 8080 CP/M version?

jrdres

năm ngoáidiscuss

Wildberger has always been this way. Way back in 2007, Marc Chu-Carroll's "Good Math Bad Math" highlighted Wildberger: "This isn’t the typical wankish crackpottery, but rather a deep and interesting bit of crackpottery." In brief, Wildberger is clearly educated, but also clearly rejects axioms that mathematicians accepted a long time ago (infinite sets in this case):

"Dirty Rotten Infinite Sets and the Foundations of Math" http://www.goodmath.org/blog/2007/10/15/dirty-rotten-infinit...

Wildberger also wrote a book on geometry with nothing allowed but rationals. (Or something like that.)

jrdres

năm ngoáidiscuss

Now seems to be the trend to bring TCP to retro machines from first principles.

8088 PC's already have M Brutman's "mTCP" driver. And DogCow (D. Finnigan) has been working on and off on the "Sabina" networking suite for the original 128K Macintosh on the MacGUI site: https://macgui.com/sabina/ https://macgui.com/news/article.php?t=550

Though it's a been slow going, apparently because of a day job. (Also note that the MacGUI site now requires an account to read progress posts.)

jrdres

năm ngoáidiscuss

Oh, this is DDA, not Bresenham, for lines.

An interesting point about Bresenham's algorithm is made by David Schmenk (dschmenk) on his "Bresen-Span" page:

"Take note that the algorithm can be viewed as the long division of delta-major/delta-minor. The error term is really the running remainder, and every step results in a pixel along the major axis until the division completes with a remainder. The division restarts by moving along the minor axis and adding the dividend back in to the running remainder (error term). This is a bit of a simplification, but the concept is that the long division will only result in two integral spans of pixels, depending on the value of the running remainder (error term). We will take this in to account to write a routine that outputs spans based on the two span lengths: a short-span and a long-span."

In other code, dschmenk does use DDA for anti-aliased lines.

https://github.com/dschmenk/Bresen-Span

jrdres

2 năm trướcdiscuss

The nice thing about 70s-80s computer magazines (and even some books) on archive.org is the relative lack of copyright concern: they're just out there without sign-on and checkout protection. Especially the ones for the 8-bit machines. You can find almost all the old magazines for those machines freely available, and no copyright concerns when people upload more. Even though it's still 50 years before they're public domain, in the computer world they're just "too old to worry about."

With one exception: there are absolutely no old issues of the Apple II magazine "Call A.P.P.L.E" (Apple PugetSound Program Library Exchange) anywhere online. The reason why is the group decided to keep the business going. The only place you can get those old issues is from the official callapple.org website for the price of subscription. Too bad, because there are old issues I'd love to read.

jrdres

2 năm trướcdiscuss

Don Lancaster (outside of Apple) did that. In fact, he ignored the Mac and connected a LaserWriter directly to his Apple II, and programmed in straight PostScript. Used that language the rest of his life. All the PDFs on his site were hand-crafted.

jrdres

2 năm trướcdiscuss

I don't know enough music to tell if this is insightful, or just neat pattern-matching.

A few months ago, mathematician John Baez had a series on the mathematics of various temperament and keys. Of course he knows his math, but also music thanks to being a member of rather famous musical family. (More math in the second link.)

https://johncarlosbaez.wordpress.com/2024/01/11/well-tempera...

https://johncarlosbaez.wordpress.com/2023/10/07/pythagorean-...

jrdres

2 năm trướcdiscuss

One of the first CP/M C's was BDS-C. It's claim to fame was that it compiled the source in-memory, so it was at least that part was nice and fast.

Certainly compared to Whitesmiths C for CP/M, and not just for the $700 price vs $150 for BDS-C. Whitesmiths was real, official C, direct from P. J. Plauger and V6 Unix. But each compile went through many, many, many passes on the poor floppy (including pseudo-assembly "A-Natural" for the 8080 that then translated to real assembly). Everybody complained that while very professional, it just took too long to go through the cycle.

Contemporary BYTE recommendation was to develop & iterate on BDS-C, then at the end re-compile on Whitesmiths to squeeze the best performance.

jrdres

2 năm trướcdiscuss

As other commenters have said, C didn't actually generate fast programs for 8-bit processors, or even 16-bit processors for a long time. C is a poor fit for most of them, so assembly language was the only way to go.

A contemporary source is the opinionated "DTACK-Grounded" newsletter from 1981-1985. http://www.easy68k.com/paulrsm/dg/ Hal Hardenbergh raved about the fast 68000 chip and it's wonderfully easy assembly, but lamented that everyone switched to "portable" Pascal and C to write 16-bit programs so they seemed even slower than 8-bit ones. His favorite example was a direct comparison: Lotus 1-2-3, written in 8088 assembly, vs Context MBA with the same features but written in Pascal for portability. 1-2-3 was MUCH faster than Context on the PC, and no one remembers Context today. Or the $16,000 Unix-based AT&T workstation whose floating-point benchmarks are beaten by a $69 VIC-20. (Obviously due to the C-written runtime, which even followed the C standard of promoting all single precision calculations to double so single was no faster!)

His opinion of C was "slightly-disguised PDP/11 assembly". Not too bad for the 68000, but a terrible fit for the 8088 or Z80.

Submissions

Anyone on the Internet Can Ring Your Doorbell

Around the General MIDI world in 12 pianos

comments