4 ms·

Such an odd choice not to have a timer interrupt on Apple II and then having to do this kind of trickery on a MouseCard. I guess this saved a few bucks...

zellyn 1y ago
That sentence is the Apple II hardware in a nutshell! save a chip or two but completely scramble the video buffer? Absolutely! The Commodore 64 is _so_ much better for graphics and sound it's not even funny, but if you look at the timelines, it came along a _while_ later than the Apple II.
- TMWNN 1y ago
  >That sentence is the Apple II hardware in a nutshell! save a chip or two but completely scramble the video buffer? Absolutely! Woz is one of the greatest engineers of the 20th century, and the Apple II demonstrates his talent. But his brilliance at simplifying things always straddles the line between optimized and overoptimized. The Disk II might be his greatest feat at doing more with less, while the video circuitry falls just into overoptimization, given the color fringing, NTSC dependence for color, and lack of lowercase. Integer BASIC is somewhere in the middle; great performance (especially given (or maybe because) Woz knew nothing about mainstream BASIC), but the code is so tightly written that it was easier for Apple to license Microsoft BASIC than to add floating-point code to Woz's work.
AndrewStephens 1y ago
I had an Apple][+ back in the day. You have to understand that the Apple][ predates what we think of as 8-bit computers by a few years and the fact it was cheap enough to mass produce was a minor miracle. Corners were cut everywhere, the Apple][+ didn't even have lowercase letters, a way to detect key up events, or a sensible frame buffer in hires mode. In its defense, it also predates a lot of what we take for granted. The idea that a game might want to scroll smoothly or update at 50/60 FPS without flickering just didn't occur to people in 1979.
- mrob 1y ago
  Galaxian was released in 1979 and features a smooth scrolling background and non-flickering sprites, all at 60 FPS. It's especially notable because it was the first game to use dedicated tiles + sprites graphics hardware, which would become the standard for arcade and console hardware and the main reason why those games looked different from computer games. The earlier Space Invaders (1978) had the CPU draw to a computer-style frame buffer with minimal hardware acceleration (only a barrel shifter to speed up horizontal movement). This was too slow to update all the aliens at 60 FPS so they would only speed up as the number remaining decreased (which worked out well from a gameplay point of view, but the original reason was a technical limitation).
  - AndrewStephens 1y ago
    OK, you are technically (the best kind of) correct. Some people were thinking of scrolling and sprites in 1979 but those people were using expensive dedicated hardware that would take a few years to filter down to home computers once people saw the advantages.
    - wat10000 1y ago
      It’s easy to forget how far apart the low and and high end used to be. When the 8-bit Apple ][ was the hot home computer, you could buy machines with 32-bit CPUs with megabytes of RAM, virtual memory, and floating point, running a multitasking, multiuser OS. But such a thing cost more than a luxury car, maybe more than a nice house. Cost was the innovation for those early home computers. They weren’t doing anything remarkable, except for doing it at a price ordinary people could actually afford. If you were willing to spend more (because the computer ran your payroll, or because the computer got people to drop quarters into it all day long) you could get much more capable stuff. These days you can drop a few hundred bucks and get something that’s not too far off from the best that money can buy. The main difference between a cheap PC and what passes for a “supercomputer” these days is that the supercomputer has much better interconnects and there’s just a lot more of it.
      - 1y ago
colinlm 1y ago
To be fair, starting with the Apple IIe, the $C019 softswitch is a good, light way of syncing to VBL. Doing it with the mouse IRQ has an advantage when one requires a mouse, though: it works the same way on the whole line of Apple II computers, starting with the II+. Without the mouse IRQ, if one wants to support the whole line of Apple II computers, one has to vapor lock on the II+, remember that the IIgs's $C019 high bit means the inverse than the IIe, and the //c requires more trickery around it. (cf https://github.com/cc65/cc65/blob/master/libsrc/apple2/waitvsync.s https://github.com/cc65/cc65/blob/master/libsrc/apple2/waitv...)
mjevans 1y ago
Everything was _way_ more expensive back then, and the CRT monitors had to be driven with electron beam steering gaps (blanks) while the output cycled to the next row. Thus there was downtime for an otherwise idle chip to do some work, and yes, saving a few dollars or 10s of dollars in 1970s money was a LOT of money!
thought_alarm 1y ago
It's not odd at all for a machine that was designed in 1976/77. However, for a machine released in 1983 (the Apple IIe) it is indeed very odd. But the IIe is an odd machine in many ways. The Apple II platform stagnated as Apple poured all their resources into the Apple III (which has all those features and much more). The Apple II refused to die, so Apple assigned a pair of engineers to design a cost-reduced version of the Apple II, and this became the IIe. The goal was only to minimize manufacturing costs, so the new features like timers were off the table. The IIe became an unexpected smash hit in the home and education markets (stealing those markets from the 128k Mac), and only then did Apple devote some new resources to the platform (and reposition the 128k Mac as a laughably underpowered productivity machine). The Apple IIc (1984) was the first Apple II to get a proper modern makeover. Of course it was a flop, while the odd-ball IIe continued to fly off the shelves.

zellyn 1y ago

That sentence is the Apple II hardware in a nutshell! save a chip or two but completely scramble the video buffer? Absolutely! The Commodore 64 is _so_ much better for graphics and sound it's not even funny, but if you look at the timelines, it came along a _while_ later than the Apple II.

TMWNN 1y ago
>That sentence is the Apple II hardware in a nutshell! save a chip or two but completely scramble the video buffer? Absolutely! Woz is one of the greatest engineers of the 20th century, and the Apple II demonstrates his talent. But his brilliance at simplifying things always straddles the line between optimized and overoptimized. The Disk II might be his greatest feat at doing more with less, while the video circuitry falls just into overoptimization, given the color fringing, NTSC dependence for color, and lack of lowercase. Integer BASIC is somewhere in the middle; great performance (especially given (or maybe because) Woz knew nothing about mainstream BASIC), but the code is so tightly written that it was easier for Apple to license Microsoft BASIC than to add floating-point code to Woz's work.

AndrewStephens 1y ago

I had an Apple][+ back in the day. You have to understand that the Apple][ predates what we think of as 8-bit computers by a few years and the fact it was cheap enough to mass produce was a minor miracle. Corners were cut everywhere, the Apple][+ didn't even have lowercase letters, a way to detect key up events, or a sensible frame buffer in hires mode. In its defense, it also predates a lot of what we take for granted. The idea that a game might want to scroll smoothly or update at 50/60 FPS without flickering just didn't occur to people in 1979.

mrob 1y ago
Galaxian was released in 1979 and features a smooth scrolling background and non-flickering sprites, all at 60 FPS. It's especially notable because it was the first game to use dedicated tiles + sprites graphics hardware, which would become the standard for arcade and console hardware and the main reason why those games looked different from computer games. The earlier Space Invaders (1978) had the CPU draw to a computer-style frame buffer with minimal hardware acceleration (only a barrel shifter to speed up horizontal movement). This was too slow to update all the aliens at 60 FPS so they would only speed up as the number remaining decreased (which worked out well from a gameplay point of view, but the original reason was a technical limitation).
- AndrewStephens 1y ago
  OK, you are technically (the best kind of) correct. Some people were thinking of scrolling and sprites in 1979 but those people were using expensive dedicated hardware that would take a few years to filter down to home computers once people saw the advantages.
  - wat10000 1y ago
    It’s easy to forget how far apart the low and and high end used to be. When the 8-bit Apple ][ was the hot home computer, you could buy machines with 32-bit CPUs with megabytes of RAM, virtual memory, and floating point, running a multitasking, multiuser OS. But such a thing cost more than a luxury car, maybe more than a nice house. Cost was the innovation for those early home computers. They weren’t doing anything remarkable, except for doing it at a price ordinary people could actually afford. If you were willing to spend more (because the computer ran your payroll, or because the computer got people to drop quarters into it all day long) you could get much more capable stuff. These days you can drop a few hundred bucks and get something that’s not too far off from the best that money can buy. The main difference between a cheap PC and what passes for a “supercomputer” these days is that the supercomputer has much better interconnects and there’s just a lot more of it.
    - 1y ago

colinlm 1y ago

To be fair, starting with the Apple IIe, the $C019 softswitch is a good, light way of syncing to VBL. Doing it with the mouse IRQ has an advantage when one requires a mouse, though: it works the same way on the whole line of Apple II computers, starting with the II+. Without the mouse IRQ, if one wants to support the whole line of Apple II computers, one has to vapor lock on the II+, remember that the IIgs's $C019 high bit means the inverse than the IIe, and the //c requires more trickery around it. (cf https://github.com/cc65/cc65/blob/master/libsrc/apple2/waitvsync.s https://github.com/cc65/cc65/blob/master/libsrc/apple2/waitv...)

mjevans 1y ago

Everything was _way_ more expensive back then, and the CRT monitors had to be driven with electron beam steering gaps (blanks) while the output cycled to the next row. Thus there was downtime for an otherwise idle chip to do some work, and yes, saving a few dollars or 10s of dollars in 1970s money was a LOT of money!

thought_alarm 1y ago

It's not odd at all for a machine that was designed in 1976/77. However, for a machine released in 1983 (the Apple IIe) it is indeed very odd. But the IIe is an odd machine in many ways. The Apple II platform stagnated as Apple poured all their resources into the Apple III (which has all those features and much more). The Apple II refused to die, so Apple assigned a pair of engineers to design a cost-reduced version of the Apple II, and this became the IIe. The goal was only to minimize manufacturing costs, so the new features like timers were off the table. The IIe became an unexpected smash hit in the home and education markets (stealing those markets from the 128k Mac), and only then did Apple devote some new resources to the platform (and reposition the 128k Mac as a laughably underpowered productivity machine). The Apple IIc (1984) was the first Apple II to get a proper modern makeover. Of course it was a flop, while the odd-ball IIe continued to fly off the shelves.