The trick is actually surprisingly straightforward. When you're drawing a circle with something like the midpoint circle algorithm (which it sounds like Bill might be using), you typically just draw one octant, and then mirror the curve 8 times. Let's say the center of your circle is (x, y), and the point you want to mirror is at (x + dx, y + d). The full collection of 8 mirrored points are:
 (x + dx, y + dy), 
 (x + dy, y + dx), 
 (x + dx, y - dy), 
 (x + dy, y - dx), 
 (x - dx, y + dy), 
 (x - dy, y + dx), 
 (x - dy, y - dx), and
 (x - dx, y - dy).
 The trick to a RoundRect is to move the centers of those reflections to the four corners, offset inward by radius r. If my rectangle goes from (x0, y0) to (x1, y1) and my radius is r, I have four imaginary "inner corners" at (x0 + r, y0 +r) and (x1 - r, y1 - r). (Assume x0 < x1 and y0 < y1.) So now my 8 mirrors become:
 (x1 - r + dx, y1 - r + dy),
 (x1 - r + dy, y1 - r + dx),
 (x1 - r + dx, y0 + r - dy),
 (x1 - r + dy, y0 + r - dx),
 (x0 + r - dx, y1 - r + dy),
 (x0 + r - dy, y1 - r + dx),
 (x0 + r - dy, y0 + r - dx), and
 (x0 + r - dx, y0 + r - dy). 
 The cost of drawing a RoundRect should be little more than the cost of drawing the circle of radius r and the original rectangle.

It has been many years since this article, and the next latest comment. I was a young engineer in 1984, just out of college, and after playing around with a Mac at a local computer store I decided that I was going to buy one. They were running a special, bundling an ImageWriter with the Mac for $2495, a price that my girlfriend and I saw as astronomical. I was making a salary of $23K at the time, and we realized that we had to take out a bank loan for the computer. The banker nearly laughed at us, and asked if we had any collateral. We finally got a loan, and I spent my spare time learning to program the incredible machine in various languages such as Pascal, FORTH, and Assembler. This experience eventually landed my a hardware/software job developing products for the entire Macintosh line (which by then included the SE and MacII). Today, I am typing this note on my Mac Studio with 64GB of memory, and the machine cost me just about the same amount of 2023 money ($2600). My career wouldn't have been the same if I had not taken the chance of buying that "expensive" Mac in 1984. Macintosh forever!

Here is more about the Andy Warhol story: https://www.vintag.es/2022/10/steve-jobs-showing-off-macintosh.html

a weird glitch seem to have happened to images in some of the stories, here's the correct url for the one just above: https://www.folklore.org/images/Macintosh/bicycle.gif

these are such fantastic tales, thanks Andy! here's the correct link to see the broken image: https://www.folklore.org/images/Macintosh/us2.jpg

One reason the PC board was very ugly had to do with industry standards at the time. The industry had somehow settled on 40 pins max for a chip. Pins are metal wires which stick out from the chip, and connect the silicon to the rest of the board. The 8088 adhered to this standard. This created an issue, because when you add 20 pins for address and 8 pins for data and then various other control pins, you quickly get more than 40 pins. The Intel engineers solved this problem by "overlapping" 8 data pins with the 20 address pins. This was clever, but immediately caused board designers to include complicated glue chips to handle this dual pin use. The processor would send the 20 bit address on the 20 pins. The board designer would then have to "capture" this address externally, because the address would then disappear as the pins switched to either receiving or sending data. The 68000 solved this a different way. They realized the 40 pin limit would eventually have to be broken because Moore's law would require it, as processors got wider. This is why they chose to use 64 pins for the 68000. It added to the cost of board design, but because you needed far fewer glue chips it probably saved money overall. Today it is funny to think about this, as chips have 100's and 100's of "pins". Since most chips are surface mounted now, they actually have pads and not pins. Here is the pinout for the 8088: https://www.cpu-world.com/info/Pinouts/8088.html Here is the pinout for the 68000: https://www.cpu-world.com/info/Pinouts/68000.html Notice the 68000 has 24 pins for address and 16 separate pins for data. While the 8088 has 20 pins for address where the first 8 can also be used for data (ad0 - ad7)

When the MacXL came out, Apple sold a kit that converted a LISA to a MacXL by swapping out the ROMs and adding a flyback transformer.I had the idea while at university (Cal Poly) to make a daughter board for the Lisa that housed both sets of the ROM, and enable one to run the machine as either a Lisa or MacXL. A simple toggle switch flopped the flyback in and out, and used the tri-state pins on the ROMs to select which to use. I was working in the terminal repair shop at school then (anyone remember the teleray 10-T?), and my colleague there, John Byrne, and I started a small company to make and sell them, Orphan Technology. We sold a few hundred, I think, before we sold the balance of the stock to sweet old Sam Neulinger. Not bad for a Mechanized Agriculture major.

I bought one. It worked great for my purposes, which was to print out the code I was writing for a Monopoly game. No individual pages needed. The thermal paper came on a roll. I still have the printer and a roll of unused paper.

I was there! Greatest group of people from Apple. They hired 200 of us kids from Santa Cruz to work the festival. 17! Years old! As press escorts! Well my sub group anyway. What a blast. Bused us down a week early and then back home 3 days after it ended. Short of it: we got paid, had all access pass, met everyone! Ate for free. Free camping in big top tent. Backstage. The best 2 weeks of my life. Did the same thing at number 2. Almost got run over by BG motorcycle! During setup. It had a huge sidecar attached. I hung out in the tech tent for so long. It was very cool. Every computer and not that crowded. I interacted with Apple folks so many times. I should have took that job! I wanted southern cal and declined after graduation. Thank you Woz. Thank you every single Apple employee. You changed my life and the whole world. In the best way. Thank you for writing this article. We need another festival! The eighties with my favorite bands! It was the best! Thanks so much.

Around 1972 there was a FORTRAN program at our computer center that could generate high-resolution text posters. It was all based on equations so the characters could be printed at any resolution, no font bitmaps anywhere to be seen.