A single 1920x1080 framebuffer (which is a low resolution monitor in 2025 IMO) is 2MB. Add any compositing into the mix for multi window displays and it literally doesn’t fit in memory.
I had a 386 PC with 4MB of RAM when I was a kid, and it ran Windows 3.1 with a GUI, but that also had a VGA display at 640x480, and only 16-bit color (4 bits per pixel). So 153,600 bytes for the frame buffer.
The Amiga 500 had high res graphics (or high color graphics … but not on the same scanline), multitasking, 15 bit sound (with a lot of work - the hardware had 4 channels of 8 bit DACs but a 6-bit volume, so …)
In 1985, and with 512K of RAM. It was very usable for work.
For OCS/ECS hardware 2bit HiRes - 640x256 or 640x200 depending on region - was default resolution for OS, and you could add interlacing or up color depth to 3 and 4 bit at cost of response lag; starting with OS2.0 the resolution setting was basically limited by chip memory and what your output device could actually display. I got my 1200 to display crisp 1440x550 on my LCD by just sliding screen parameters to max on default display driver.
Games used either 320h or 640h resolutions, 4 bit or fake 5 bit known as HalfBrite, because it was basically 4 bit with the other 16 colors being same but half brightness. The fabled 12-bit HAM mode was also used, even in some games, even for interactive content, but it wasn't too often.
Doesn't the UEFI firmware map a GPU framebuffer into the main address space "for free" so you can easily poke raw pixels over the bus? Then again the UEFI FB is only single-buffered, so if you rely on that in lieu of full-fat GPU drivers then you'd probably want to layer some CPU framebuffers on top anyway.
Someone last winter was asking for help with large docker images and it came about that it was for AI pipelines. The vast majority of the image was Nvidia binaries. That was wild. Horrifying, really. WTF is going on over there?
You’re assuming a discrete GPU with separate VRAM, and only supporting hardware accelerated rendering. If you have that you almost certainly have more than 2MB of ram
That's only RISC OS 2 though. RISC OS 3 was 2MB, and even 3.7 didn't have everything in ROM as Acorn had introduced the !Boot directory for softloading a large amount of 'stuff' at boot time.
It was GUI defined manually by pixel coordinates, having more flexible guis that could autoscale and other snazy things made things really "slow" back then..
Sure we could go back... Maybe we should. But there are lots of stuff we take for granted to day that were not available back then.
RISC OS has the concept of "OS units" which don't map directly onto pixels 1:1, and it was possible to fiddle with the ratio on the RiscPC from 1994 onwards, giving reasonably-scaled windows and icons in high-resolution modes such as 1080p.
When I first started using QNX back in 1987/88 it was distributed on a couple of 1.4MB floppy diskettes! And you could install a graphical desktop that was a 40KB distribution!
My parents saved up for years and then kept the same computer for years more. It was normal to have a
machine for 10 years, and just one per household.
Upgrading with a hard disk, a second floppy drive, or upgrading the graphics card was common.
Great to see a discussion of Greg Kuperburg’s games. I love playing PC-MAN for 3 minutes or so with my oldest son. Perfect amount of time and attention.
I’m currently busy disassembling PC-MAN and trying to cram it into 16kB so it could be run on an original PC loaded from cassette. The game was distributed as a DOS booter and boo floppies required 32k, but PC-MAN is about 17k in size.
Or 128K of ram and 400 kb disk for that matter.
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