Questions tagged [hardware]
Retro hardware generally: boards, extension cards, power supplies, peripherals. Use more specific tags as appropriate; use [case] instead for enclosures.
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When did the PC bus start slowing access to video RAM?
The PC architecture, from the original IBM PC onward, has always been designed around the idea that video memory will be on an expansion card. This was an unusual design decision; most 80s computers ...
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Why did tactile-feedback keyboards lose popularity?
IBM spoiled me for hardware quality. I've gone through many computers, including a TRS-80, Heathkit H-89, Commodore Vic-20 and C-64, and countless PC's but my first original IBM PC will always be my ...
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Why weren't discrete x86 CPUs ever used in game hardware?
Please don't point out APUs with x86_64 cores used in current generation game consoles, these are not part of the question
I cannot recall a single arcade system or game console that ever used x86 ...
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Graphics chips in 1980
Suppose you were trying to build a computer with a color graphics display in 1980, you have limited engineering resources and time to market is critical, so you want to get as many of the parts off ...
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Is the N64 incapable of 2D graphics?
So as many fans are aware, the N64 era was a jump for many games into the third dimension. Games like Mario and Zelda were impacted in a positive way. Others... not so much. While it may seem odd that ...
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Amiga 500 left mouse button not working
I've recently bought a Amiga 500 (A6 board). This Amiga works perfectly and starts as it should, except for the fact that when I hover on a icon and click my left mouse button to open it, it doesn't ...
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What chemicals or materials were used to create the logic for logic gates?
Back in school I took a couple electrical engineering classes and we did a lot of Boolean math using logic gates (AND, OR, XOR, NAND, etc), but never talked about how exactly the logic in a single ...
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Which aspects of RF emission were TI unable to get under control?
The TI 99/4 (as opposed to 4A) was a computer killed by RF emission problems. From Wikipedia
Through the development period, several companies attempting to enter the home computer market were faced ...
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Are a Z80 address pins tristate?
I been looking at the Z80 CPU recently and am wondering how difficult it would be to wire one up. The thing I'm interested in is how to connect it to some RAM. In particular, I'd like to know if the ...
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DIY Project using 1970s 8-bit CPU, is it possible?
I've recently really wanted to try and design a computer system around a retro 8-bit CPU such as the Zilog Z80 or the Intel 8080, and I would appreciate some sanity checks! I was inspired by Ben Eater'...
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Did any Apple II games use a "timing resistor"?
A science-lab program for the Apple II (I forget the name) had a board that plugged into the joystick port and included a "timing resistor". While I don't know what the program actually did with the ...
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Maximum current a GBA Game Pak can continuously draw
The GBA (specifically model AGB-001) uses a boost converter to power the Game Pak with a stable 3.3V from its batteries. The SP and Micro models use a buck-boost regulator to generate that same 3.3V. ...
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Were there 3D accelerators built on discrete logic?
I wonder if there were 3D accelerators (that is, a device that calculates rotations, scaling, texturing, etc. for 3D points) built on discrete logic (7400 series, most likely its fastest variants, ...
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Why did the Atari 800 designers choose such a radical system design?
The physical system design of the Atari 800 was pretty radical, when compared to the 3 other canonical home computer designs of the late-1970s: TRS-80 Model 1, PET, and Apple ][.
As the photo of the ...
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What determines the color of every 8th pixel on the Apple II?
On the Apple II there's an interesting way to add a little color to the bitmap, since the high bit selects the palette used for the three-and-a-half pixels represented by the byte. Like this:
0: Black,...
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How much extra did a color RF modulator cost?
I've been doing more reading about the early 8-bit home computers, a fascinating era, in which the cost of the hardware was of course a constant, dominating constraint, and trying to understand ...
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Is there a technical reason why Datel Action Replay on PC required a card?
In the mid-90s, there was an ISA expansion card called “Datel Action Replay” that could be inserted into almost any PC-compatible machine (e.g. 80286). By pressing a button on a device (plugged into ...
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Why does the Commodore 64 have 4K of non-banked RAM at $C000?
I wonder why the Commodore 64 memory map was created as it was. Naively, it seems to be that it would have been more logical to put I/O and the character ROM at $B000 to $BFFF, have the ROMs in a ...
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What are the electrical properties of the EAR and MIC sockets on a ZX Spectrum, and can they be connected between machines?
I'm interested in the possibility of connecting two ZX Spectrum computers together using as simple an interface as possible.
The ZX Spectrum has two mono audio sockets at the back labelled EAR and MIC....
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When were other inexpensive computers able to recreate "The Amiga Juggler"?
The Amiga Juggler was the 2nd very popular demo to appear for the Amiga Computer early in its lifespan. The demo was created by Eric Graham (who went on to develop Sculpt3D) using raytracing to both ...
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Why do old computers (PCs) perform a long memory test on every boot?
Basically any computers from the mid 90s and earlier perform a slow memory check on every single boot. The more memory there is present, the slower that process becomes, for example: https://www....
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Did DEC build their early computers out of the same parts?
Considering the PDP-8, PDP-7, PDP-9, PDP-1, even though they are completely different architectures (from a programmer's or compiler's point of view at least), they have some remarkable similarities ...
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Analog to PWM for Analog input on Retro game controller?
On the NES and SNES a common feature on 3rd party controllers was "Slow-motion". It worked by repeatedly pressing and releasing the start button. Because many games simply froze gameplay ...
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Primary manufacturers of picture tubes for early monitors
Which companies were the most important manufacturers of picture tubes for monitors (both monochrome and color) in the seventies and eighties? That is, it's easy enough to find lists of monitors by ...
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What contemporary hardware was available for the development of Atari 2600 (or other 2nd gen) games?
The Atari 2600, along with others like the Odyssey 2 or Intellivision, were among the first programmable home game consoles. They existed alongside personal computers like the Apple II and Commodore ...
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Where can I find hardware details for the Philips VG-5000?
I'm interested in exactly what connectors the VG-5000 and what the pinouts are for them. Ideally, I'd like a full set of schematics for the machine.
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Why user-assembled kits?
Many early computers were sold as self-assembly kits (you get a box of parts and an instruction leaflet and have to solder them together yourself). For example, the Altair was priced at $439 kit, $621 ...
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What is this large device labelled 'Telefunken Datenspeicher' and how does it work?
We found this device in our school. Does anyone know what this can do exactly, and how it could work?
We managed to input values into the bit storage on the top, but nothing more. Can we calculate ...
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Which S-100 systems supported both hard- and soft-sectored 8-inch floppies?
In the late 1970s to early 80s incompatible system software (i.e. MicroSoft Basic and CP/M 1.4) for S100 computers could be released in 8 inch, hard and soft sector, floppy disk formats. In that era ...
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Number of transistors in the C64
How many transistors are there approximately in the C64 if we consider every chip on it? I think that it is something around 50.000 but I'm not sure.
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Were there any games/software that used memory beyond what was advertised available to BASIC on the machine?
Were there any games/software that used memory beyond what was advertised as available to BASIC on the machine ?
On home / personal computers any time up to 1984 .
Without needing to plug in any ...
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Which ports are which on this Soviet ZX Spectrum clone?
Today I got my (first) Soviet ZX Spectrum clone. The person who sold it to me had inherited it and had no idea how it worked.
It seems to be a home-made clone, rather than a factory-built one. See ...
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How was the 80186 incompatible with the IBM PC?
Wikipedia's Intel 80186 entrymentions
The 80186 would have been a natural successor to the 8086 in personal computers. However, because its integrated hardware was incompatible with the hardware used ...
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Atari SIO vs IEEE 488
When Atari was designing the 800 series of computers, they needed a way to connect peripherals. To comply with FCC regulations on RF emission, it needed shielded cables. To achieve low cost of entry ...
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Which computers used the Intel 82786 graphics chips, and what sort of commercial success did that chip attain?
In the late 1980's, Intel offered the 82786 graphics chip, with specific support for windowed environments. I remember it being covered in Byte magazine, but don't remember seeing any applications of ...
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What's the required battery voltage within a DALLAS DS12C887+ RTC? [closed]
I am having some difficulty getting a board that has a Dallas Real Time Clock DS12C887+ to behave. Not sure if the problem is the RTC or not but am in the investigative stage and got the cross hairs ...
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How can the number of cylinders supported by a floppy drive be different from the number of tracks?
In the IBM PC 5150 documentation, it is stated that the floppy drive has 40 tracks, 8 sectors/track and 512 bytes/sectors, for a total of 163 840 bytes of data. It makes sense, 40×8×512 = 163 840 ...
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VAX 11/780 16MB memory board - what was the physical size?
I'm trying to get a feel for what it looked like when you designed a computer to have a lot of memory chips stuffed into it. To that end, I found this: https://commons.wikimedia.org/wiki/File:...
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Did the Timex Sinclair 2068 and the Sinclair ZX Interface 2 use totally different hardware and software techniques?
Sinclair released an add-on for the Spectrum called the ZX Interface 2 that provided joystick ports and a cartridge slot. It wasn't successful and only a few cartridges were ever produced.
In the US, ...
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Why must the Amiga 1020 disk drive be powered-on before and powered-off after the Amiga computer?
The Amiga 1020 was a 5.25" disk drive for use with the Amiga computer. Anecdotally, I suspect they are somewhat rarer these days because they were a less popular choice for a second drive back in ...
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What documentation was provided with the Amiga 1020 disk drive?
The Amiga 1020 was a 5.25" disk drive for use with the Amiga computer. Anecdotally, I suspect they are somewhat rarer these days because they were a less popular choice for a second drive back ...
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Gameboy Key Input Causes Crash
I made a Key Tester using the STDIO header included with GBDK. It works... Until it doesn't. All the keys register and print to the screen, except the Left(5) and Right(4) Directional Keys, which ...
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Why would installing Windows 9x on a Sager NP8200 or Wedge 466/DX2 laptop brick the system?
In the setup.txt file on the Windows 95 and 98 CDs (located in the \WIN95 [Windows 95] / \win98 [Windows 98] folder), which contains important information on setting up Windows and solving or working ...
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Was there a retro computer susceptible of being damaged only by issuing instructions at it?
The question 'Can a USR command damage a ZX Spectrum?' has led me to wonder if there was once a microcomputer that could actually be damaged by software.
More specifically:
Is there a case that a ...
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First time seeing this odd little PCB inside a Playstation 2; What is it for?
I have opened a few Playstation 2 consoles to fix or clean them so far and I have never seen this weird little board before. It is connected to where the ribbon cable for the front panel (power/reset ...
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Can the MC6850 ACIA signal that it wants to send data but not receive it?
I want use MC6850 ACIA for bidirectional communication, but I am not sure if I've understood it well.
I want use an IRQ to interrupt an MCU when the ACIA receives data or has transmitted it. The MCU ...
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Did any computer use a 7-bit byte?
In an answer to Why did IBM System 360 have byte addressable RAM I wrote regarding the choice of byte size:
7 bits would be a perfect match for ASCII, but engineers would instinctively recoil from ...
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Was there any computer since about 1960 without interrupt support?
The invention and spread of interrupts in the 1950s is reasonably well known but I am curious: were there any systems after which didn't support them?
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Where can I find a schematic of the AT&T KBD 301?
Where can I find a schematic of the AT&T KBD 301?
I have an old AT&T 6300 (AT&T's rebrand of the Olivetti M24) but the keyboard (AT&T KBD 301) is not working.
Many of the keys do work ...
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What did the 'turbo' button actually do?
I remember the computer I played Commander Keen on as a child had a turbo button that I was forbidden to touch, what did this button actually do?
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