Questions tagged [video]

For questions regarding hardware and drivers used for video output.

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5
votes
1answer
213 views

Did any ZX Spectrum clones use a 16 bit datapath between memory and video generation?

On the Commodore 64, there is a 12 bit datapath between memory and the VIC II: the ordinary screen data, which is in DRAM, and another 4 bits which comes from another SRAM chip which may be paged into ...
13
votes
5answers
4k views

Why didn't early color TV sets accept RGB input?

Early PCs generated RF signal, and later Composite video or S-video, to use a TV set as monitor. Why didn't color TVs of those days expose a analog RGB interface for direct connection from VCR/PC or ...
19
votes
5answers
3k views

Why did the VIC-20 and C64 have only 22 and 40 columns when the earlier PET had 80 column text?

When I was a kid, the "real" computers in movies looked so cool with that 80-column monochrome green text. My first computer was a VIC-20 it always felt very "toy" to me because of ...
0
votes
1answer
192 views

Workbench 3.1 Chipsets and graphics question

I have Workbench 3.1 install with Scalos and some other tweaks installed from scratch using one of numerous online guides. My machine is a CDTV with 3.1 Kickstart, TF536 030 MMU 64MB RAM. The chipsets ...
1
vote
1answer
192 views

RGBI to VGA converter [duplicate]

Is there an off the shelf converter / adapter from C128 RGBI to VGA that will work with modern-ish low voltage VGA?
-1
votes
0answers
125 views

Strange behaviour of RGB2HDMI converter

I'm using a generic RGB2HDMI converter, which last time I remember worked just fine. Was safely stored for the last 4 months, no moist, damage, nothing. Just connected it and I get this behaviour. Not ...
0
votes
1answer
181 views

Operating system/hardware used for playing a video during a recorded trial that took place in 2013 [closed]

I am watching a 2013 murder trial on YouTube Jodi Arias Trial : Day 23 : 1 Of 3. There is a considerable amount of evidence involving phones and computers. The following picture briefly appears on-...
5
votes
1answer
216 views

Did the Power Macintosh 8500 have accelerated blitting?

Looking at online specifications for the Power Macintosh 8500, I was able to find few details on its graphics capabilities beyond quantity of VRAM and supported color depths, refresh rates, and ...
5
votes
1answer
364 views

Are there any 1980's video chips still available besides the TMS9918?

The TMS9918 is still available, which is nice. But are there any other (better) video chips still on the (after-)market in any numbers? Obviously Commodore's VIC-II is not one of them.
5
votes
2answers
549 views

Sony PVM Connections / Composite Signale

I am trying to learn more about different video formats. I have a SONY PVM9044QM and want to understand the different connection options. So I understand, that Y/C equals S-Video input. But what does ...
3
votes
1answer
286 views

What old version of Windows provides out-of-the-box DVD movie playback?

I bought a Playstation 2 in 2000, which famously included a DVD drive capable of playing DVD movies. I wanted the same movie playback capability on my Windows 98 PC. As I recall, I mistakenly thought ...
4
votes
2answers
354 views

Vintage computer composite graphics

I am working on designing a vintage computer and I have been using the TMS9918ANL. After working with it for a month or two and not making much progress, I really want to switch to another chip. I am ...
8
votes
1answer
791 views

What kind of 256 color palette did the Enterprise 64/128 have?

The Enterprise 64 or 128 Home Computer apparently had a palette of 256 colors. However, that is pretty unusual and doesn't fit evenly into the typical 3 channels for RGB. Wikipedia doesn't provide any ...
11
votes
2answers
191 views

Which addresses does the Motorola 6845 CRTC output during retrace?

I'm trying to understand how the video hardware (CRTC and Gate Array) in Amstrad CPCs works. Specifically, I have a question about the behavior of the refresh memory addresses and row adresses output ...
8
votes
3answers
818 views

Why does the Amiga 500 have half the HSYNC pulses seperately compared to those in CSYNC?

After many years I bought myself a new old Amiga 500 (rev 5) and wanted to hook it up to an LCD monitor (Samsung Syncmaster 152N) that has a VGA input. I tried hooking it up directly by making an ...
6
votes
1answer
586 views

Is there a generic VBE driver available for Windows 3.x?

I’d like to run Windows 3.11 on a relatively modern laptop. One problem I have is that the only display driver that works with my hardware is the basic VGA driver, which only supports the rather ...
6
votes
1answer
409 views

Was it ever possible to access the full EGA color space in 200-line modes?

It's long been an established fact that the EGA only had four memory planes, which limited the number of colors on the screen to (24) 16. The best compatible monitors at the time had six TTL color ...
3
votes
1answer
151 views

`DRAW` instruction timing

I asked a question here about CHIP-8 instruction timing, and this answer mentions that DRAW waits for vblank: For Chip-8 code that draws anything, the limiting factor will be the wait-for-vblank that ...
8
votes
2answers
775 views

Could CGA synchronize with vertical blank?

According to http://www.vcfed.org/forum/showthread.php?62049-The-myth-of-the-vertical-retrace-interrupt-on-EGA-VGA IBM first implemented a vertical retrace interrupt on the PCjr in 1984. That ...
32
votes
3answers
10k views

Why do PCs boot in 720x400 resolution?

Using my 21" Trinitron OSD, I can see that the resolution at boot is 720x400. From memory, this weird resolution is extremely uncommon if ever to be seen as a choice on software that supports ...
0
votes
1answer
104 views

How exactly does Leningrad contend the memory?

From what I understand of this answer, the Leningrad delays the Z80 during the M1 cycle so that the video generation circuitry can do its thing. I can see how M1 is "latched" (don't know if that's ...
1
vote
0answers
255 views

Thinking through the design of a TTL video card: what memory chips and how to manage memory? [closed]

Inspired by Ben Eater's "Let's build a video card" aka "World's worst video card" two part projects on YouTube, I was inspired to consider designing a display adapter for my passive backplane TTL mini-...
6
votes
1answer
360 views

What role does the 4-bit shift register play in the Leningrad video generation?

The Leningrad contains a shift register1, which I believe is loaded with data from the bitmap. This part loads 8 bits in parallel, and shifts each bit out in turn on the rising edge of a clock signal. ...
35
votes
2answers
3k views

What mid-1970s to mid-1980s home computers had their graphics characters added to Unicode 13?

The Unicode 13.0.0 release notes mention among the symbol additions: 214 graphic characters that provide compatibility with various home computers from the mid-1970s to the mid-1980s and with early ...
6
votes
3answers
812 views

How does the Apple II read lines for video display from the text-mode frame buffer?

(This question applies also to the low-resolution graphics video buffer, since that uses the same frame buffer as text mode, just displaying it differently.) As described on page 1-12 et seq. of The ...
10
votes
4answers
3k views

Is it possible to swap the Apple IIc's monochrome CRT tube for a color one?

I just love the Snow White industrial design language of the Apple IIc, especially when paired with the Monitor IIc. It is a classic design that doesn't show its age. I've even recently seen them ...
5
votes
2answers
929 views

Could early nineties PCs access raw CD bitstream?

In the early nineties, as discussed in What specific technical advance(s) allowed PCs to play "Full-screen full-motion" video? it became commonplace for PC games to use the storage capacity ...
18
votes
2answers
4k views

How did the Sega CD decompress video?

In the early nineties, Sega released the Sega CD, a.k.a. Mega CD, an add-on that attached a CD-ROM drive to the Mega Drive a.k.a. Genesis. Its primary or at least most conspicuous use was for full-...
2
votes
1answer
269 views

What is the format of the Apple 1 character set ROM?

What is the format of the video character ROM used in the Apple 1?
18
votes
7answers
3k views

Cost of unrestricted sprites

All the game consoles of the second through fourth generations, and several early home computers, had sprites, which were valuable though costly, e.g. the VIC-II spent 2/3 to 3/4 of its area on ...
5
votes
2answers
287 views

Could monochrome systems produce better output for monitors than TV sets?

Many classic computers could optionally use a TV set as the display. At least in the early (pre-SCART) days, the TV would typically only have RF input, but if you were using a monitor, you could get a ...
6
votes
2answers
659 views

What was the title safe area on PAL TV sets?

Computers that used TV sets for display, needed to worry about the title safe area. By consensus, on NTSC sets, it was 200 scan lines, or 192 if you wanted to play it really safe. What was the ...
12
votes
1answer
675 views

How did the Apple 1 video circuit work?

One of the major innovations of the Apple 1 when it was released in April 1976 was that instead of using a serial interface requiring an expensive external terminal it had a built-in 40×24 text video ...
5
votes
1answer
471 views

(How) can I boost my ZX81 video output with an external device?

I bought a small LCD TV today in part to use with my retro computers. My Sinclair ZX Spectrum 48k works perfectly with it - I can manually fine tune Channel 36 as shown in this video. With the ZX81 I ...
9
votes
2answers
2k views

What was the screen refresh rate of the Lisa and original Macintosh?

According to https://www.folklore.org/StoryView.py?project=Macintosh&story=Joining_Apple_Computer The Apple II displayed white text on a black background. I argued that to do graphics properly ...
43
votes
2answers
9k views

Why were some early PC 3D cards unsuitable for 2D graphics?

Some of the early PC 3D graphics cards such as the 3dfx Voodoo Graphics cards had a passthrough port to enable them to switch to a secondary card to display 2D graphics. I am curious to know why these ...
8
votes
1answer
269 views

What was the purpose of the Apple /// interlace mode?

I know that a video interlace mode was available on the Apple /// prototype and eventually on the Apple ///+, but I haven't seen anything that says what it was for. Did it provide a higher resolution ...
6
votes
4answers
771 views

Are there standard DIN pinouts for cassette and video ports on early Japanese 8-bit computers?

I have several different Japanese 8-bit computers, and they use similar DIN connectors for video and cassette I/O: Composite video: 180° 5-pin DIN: Fujitsu FM-7, NEC PC-8001mkII Color TTL (digital) ...
6
votes
2answers
827 views

GPU chip implementation on CPU - will it be faster? [closed]

So, modern video cards include two devices - a video signal generator and a graphic accelerator. The first of them converts data from video memory into MDA / CGA / VGA / RCA / DVI / HDMI / etc format....
11
votes
3answers
728 views

What are the Ultra-Highres registers in ECS and AGA for?

The Amiga custom chip set, in its ECS and AGA versions, seems to contain some registers for what is called an "Ultra-HighRes/DUAL" mode: DFF078 SPRHDAT W Ext. logic UHRES sprite pointer and ...
13
votes
2answers
654 views

Atari ST DRAM timing puzzle

From the Atari SM124 Monochrome Monitor Service Manual, I get that the video signal timing for one line is 20µs. With the horizontal resolution of 640 pixels, this gives a 31.25ns pixel clock. Using ...
38
votes
8answers
13k views

Why did computer video outputs go from digital to analog, then back to digital?

While early microcomputers used analog video outputs (often to use a television as a display), higher end machines such as the BBC Micro or Commodore 128 supported a digital RGB (or RGBI) video output....
6
votes
4answers
2k views

High-end PC graphics circa 1990?

I remember CAD being a major driver for PCs with high-end graphics cards; specifically AutoCAD was rising quickly in popularity around 1990 as PCs were able to compete with very costly CAD ...
55
votes
6answers
13k views

How did old MS-DOS games utilize various graphic cards?

Nowadays each graphic card has some driver in operating system that translates some (typically) standard API such as OpenGL, so that programmers use some standardized API code to tell graphics cards ...
5
votes
1answer
321 views

Apple I and II video output to a contemporary TV set?

Is it possible to connect the unmodified video output from an Apple 1 and Apple II (with their non-standard/out-of-spec NTSC sync pulse levels and/or timings) to a (currently in-production and ...
9
votes
3answers
2k views

What is the best option to connect old computer to modern TV

I was exploring different options of connecting both my Atari ST and C64 to a modern TV. I opted for a composite signal passed through a cheap AV to VGA converter, and although the display works, ...
4
votes
1answer
384 views

Atari 1040ST AV video output - blurred and jagged vertical edges

I have an AV cable that connects Atari 1040STE with a AV to VGA converter. For some reason the vertical edges are not sharp, rather jagged or pixelated. I red that old atari would have an issue with ...
8
votes
1answer
1k views

When did MS Windows get Dual Monitor support?

I remember one of the features I admired on the Macintosh in the late 80s was support for multiple displays. First time I saw this was on an SE/30, using the internal display along with a big external ...
1
vote
0answers
95 views

Cannot get K prompt on Timex 1500 [closed]

I started tinkering with a Timex Sinclair 1500 I was given awhile ago. When I first tried starting it, I got a K prompt in the lower left of the screen. I turned it off and did not return to it for a ...
4
votes
2answers
430 views

When were sprites first displayed in the border area?

I assume one of the first undocumented effects on the VIC-II was the ability to display sprites in the (upper and lower) border area. I wonder how and when this was first discovered and used? Was it ...