Questions tagged [hardware]

For questions about the components of retro devices (computers, etc.)

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5
votes
2answers
258 views

Is it possible to upgrade original iMac (1998) memory (RAM) to above 256 MB?

I am looking into buying myself an original iMac, as I want to mess with the older system a little bit. Is it even remotely possible to change the RAM in the system to being over 256 MB? I am willing ...
6
votes
1answer
474 views

How can I edit CMOS hard drive geometry settings on a 1991 PC?

First, I am NOT asking how to use the BIOS Setup utility. I'm asking how to OVERRIDE the built-in settings my BIOS Setup supports for the HD geometry. I have a 1991 NCR PC with a 386SX, on-board IDE, ...
10
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4answers
1k views

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 ...
2
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1answer
256 views

“Unexpected interrupt in protected mode” after installing 486 DX2

I've got a Packard Bell Legend 245 that's been running a 486 DX at 33 MHz. The board is Socket 2, and says Intel Overdrive Ready. I bought a 66 MHz DX2 under the assumption that it's just a drop-in ...
16
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1answer
2k views

How do accelerators and CPU cards work on the Apple II?

An Amiga 1200 exposes the entire CPU bus on the expansion port, so that an accelerator only needs to assert BR which causes the onboard CPU to stop all computation and electrically disconnect from the ...
5
votes
2answers
359 views

Do TG16 games and software suffer from lag frame similar to NES Super Mario Bros?

As a speedrunning fan, I've watched hours of Super Mario Bros speedruns, and have heard the term "lag frame". I don't think it's similar to typical computer lag, but instead an extremely technical ...
8
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1answer
580 views

RAM for Socket 7 Motherboard - 64MB sticks appearing as 16MB

I hope this is the right place to ask this and that it is "retro" enough. I have a Socket 7 machine that I am working on. It's my 1st PC from childhood that I restored, and now I would like to ...
5
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2answers
332 views

Method for adding firmware to a Commodore 64 expansion card?

The C64 expansion port can and does support multiple IO devices without conflicts. There is 0.5 KiB that is decoded for $DE00-$DFFF, using /IO1 and /IO2 on the expansion port. As long as the devices ...
18
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2answers
2k views

Why do old computers 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....
12
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3answers
3k views

What happened to ZIP RAM?

I have several retro machines and add-on cards for the Amiga that use ZIP RAM. This vertically mounted chip design enjoyed a brief popularity in the early 1990s, in between the original DIP DRAM and ...
10
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1answer
2k views

Connecting Panasonic “Penwriter” RK-P400C to modern PC using USB to serial cable

I have a Panasonic "Penwriter" model RK-P400C electronic typewriter/plotter from circa 1985 I'd like to be able to connect to a modern PC. And hopefully even use to draw graphics! Bought in almost new ...
4
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3answers
562 views

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 ...
8
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1answer
545 views

On the bbc-micro, a half-size mode 1 screen mode with 16 colours instead of 4 can fit in memory but can the video chip be programmed for it?

Screen Mode 2 on the BBC micro is 160 x 256 with "16"* colours. This uses up 20Kb of memory. Horizontal-rectangular pixels ( 2 x squares each). 4 bits per pixel (0-15 values for 16 colours) Screen ...
4
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3answers
359 views

TMS9918 with shared memory

The TMS9918 video display processor was designed in the 70s to have its own memory connected directly to it, and provides an interface that allows the CPU to read or write the memory during cycles in ...
3
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6answers
806 views

A different way to share the memory bus between the CPU and the Video

Considering the ZX Spectrum, part of the memory is accessible to both the ULA and the CPU, and the CPU is slowed down when it is using that area, so that the framebuffer can be read out. As I ...
5
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5answers
3k views

Is my understanding right about the actual differences between 240p and 480i?

After reading around on the web, including the authoritative site Scanlines Demystified I still am having trouble understanding the difference in signal between 240p and 480i. After reading the wiki ...
7
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2answers
532 views

Strange “snow” artifacts when dragging a window in 256-color mode

I picked up a nice Packard Bell Legend 245 over the weekend, and it works great apart from one issue so far: when dragging windows around the screen (Win 3.1), the screen gets corrupted with weird ...
3
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0answers
343 views

When did green LEDs become as cheap as red LEDs? [closed]

Blue LEDs in the cheap, practical form we know them today, arrived in the 90s; before that, the choices were red and green. I want to say there was a time some years before that when green LEDs ...
5
votes
1answer
309 views

Recent article about using Apple II for security purposes

I'm looking for the article for a project. It is fairly recent, may have been a news article, or a blog. It in turn might have referenced a scholarly paper. Anyway, the gist of the article was that ...
5
votes
3answers
422 views

What is the optimal way to store retro computing paraphernalia (games, consoles, accessories, books) on display at home?

When collecting retro computing related items you'll undoubtedly end up with a variety of different items, made from different materials and in a range of conditions. Here is a recent snap of my ...
46
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8answers
11k views

Why were chips socketed in early computers?

In many early computers, many of the chips were in sockets rather than soldered directly to boards, e.g. this series of pictures of the Tandy CoCo 1 has a note to the effect that all the chips are ...
6
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2answers
240 views

Do all Econet devices need the same clock speed?

Econet was a network used by the BBC Micro, conceptually similar to Ethernet, two orders of magnitude slower and correspondingly cheaper. According to https://en.wikipedia.org/wiki/Econet it ...
9
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5answers
1k views

Largest practical motherboard for early computers

The power of a computer is often effectively determined by the size the RAM can be expanded to. In many cases, this was even more important than CPU speed: Memory-limited workloads In the early days, ...
11
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4answers
1k views

Smallest/Simplest, modern pure relay computer with at least 4-bits data words

There are a lot of designs out there of modern home made relay computers (not just ALUs but real computers -let's call them Turing complete, although Turing complete is not enough for having an ...
14
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4answers
5k views

What was computer “Fuzzy” logic?

In the mid 1980's computers began to be advertised as having or being capable of "Fuzzy" logic. How was "Fuzzy" logic added to a computer and what was it suppose to do better than a computer without ...
7
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5answers
494 views

How to protect a ZX Spectrum mainboard from “ageing”?

I have some ZX Spectrums, and in some of them I observe a kind of "disintegration" process of the main board. The connectors break away etc. During the tests one of the boards burned out :(. How can ...
7
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0answers
340 views

How was the Intel 80486 debugged? [closed]

How was the Intel 80486 (from 1989) debugged? I'm assuming it was written in some HDL language, like Verilog. However, how was testing and debugging of the CPU carried out? Were there several steps ...
9
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1answer
443 views

How did the Commodore PET 80 column display work?

Some variants of the Commodore PET (e.g. the 8000 and 9000 series, as well as some other versions with an aftermarket add-on) produce an 80x25 character display. Their character set is fixed in ROM ...
25
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4answers
5k views

How did the BBC Micro stay cool?

The BBC Micro used the extended variant of the classic 'computer in keyboard' design; like the Apple II, the case went back far enough that you were encouraged to put the monitor on top of it. All ...
3
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2answers
379 views

When did the Macintosh start using four (or more) layer PCB's?

I'm assuming (but do not really know) that the original Macintosh used a two layer PCB. So my question is, when did the Macs start using more complicated boards with four (or more) layers? For ...
8
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2answers
3k views

Was the IBM 5100 ever used for codebreaking?

There's a rumor that there's something embedded in the IBM 5100 which makes it useful for codebreaking. What is the legitimacy of that claim?
5
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3answers
606 views

What was the first integrated PC compatible computer?

When IBM developed the PC, they famously chose a bunch of off-the-shelf components. Besides making the machine relatively easy to clone, another effect of this was it used a lot of chips and board ...
8
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4answers
960 views

Why the switch to “Mickey Mouse” (type C14) power cables?

Inspired by this question asking about "regular" power cables, I have been curious about (read: irritated by) the rise of "Mickey Mouse" power cables. Apparently they come from the same standards ...
2
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1answer
1k views

Physically emulate Gameboy cartridge using Raspberry Pi? [duplicate]

This is an extension to the question NES cartridge rom emulation with arduino or pi?, which asked whether it would be possible to physically emulate a NES cartridge using an Arduino/Raspberry Pi (RPi)....
27
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7answers
11k views

Why did computers use a power supply with a socket?

Most home electrical appliances use a fixed power cord and have a on/off switch near the front. I was in many government electronics labs and that cord and socket was not used i.e HP test equipment. ...
4
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0answers
252 views

Cost of Apple II switching power supply

Apple went to the trouble of designing a switching power supply at a time when they were still quite new and not widely used for consumer electronics, perhaps because Steve Jobs liked the aesthetics ...
1
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2answers
253 views

Conventional Hard Drive life-span [closed]

I have a bunch of hard drives. From 500 megabytes to a few gigabytes from years around 2000-2006. I was wondering if those are still readable or are dead. Should I hurry up finding an adapter and try ...
1
vote
2answers
197 views

Lead Free Solder in Pre-2006 Electronics

In 2006, the European Union passed the Restriction of Hazardous Substances Directive (RoHS) which pretty much restricted the use of traditional lead-tin solder. Is it the case that all consumer ...
9
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2answers
542 views

8086 pinout and address space limit

It is tempting to say - and I have said - that Intel made a mistake in the design of the 8086 and 8088, in going from 16 bit addresses to only 20 bits; if they had even shifted the segment registers ...
1
vote
1answer
100 views

Osborne Turbomate IV Information?

Howdy Retro Computing Stack Exchange, I semi-recently came into possession of an Osborne Turbomate IV computer with an Ipex monitor and Brother dot matrix printer (along with original Osborne mouse ...
109
votes
4answers
26k views

It's now safe to turn off your computer

One thing I remember very well from my childhood is the screen you got at the end of a shutdown process ond old computers: I don't know if this was a Windows 95/98/2000/ME only thing but I wonder why ...
30
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5answers
6k views

Why do hard drives not use larger platter sizes anymore?

In reading a related question about floppy drive capacity, I thought to ask a question I've had for a long time. When I started programming, all PC hard drives used the 5¼" platter size. There were ...
11
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8answers
2k views

Why did common floppies never advance past 1.4 MB in size?

The chronology of some early floppy standards was: 80 kB, 160 kB, 360 kB, 720 kB, 1.2 MB, finally 1.44 MB. (There were less common sizes such as 250 kB, 800 kB, ...
10
votes
1answer
412 views

VIC-II transistor count

I'm curious about the transistor count of the VIC-II, the video chip in the Commodore 64. According to http://visual6502.org/wiki/index.php?title=Chips_in_our_collection the Atari 2600 TIA chip has ...
0
votes
2answers
278 views

What was the first piece of hardware to utilise quantum effects? [closed]

Processors used to be mechanical, using macroscopic switches and gears. Then they began to use valve switches. Then they used microscopic circuitry that you could only see with a powerful magnifying ...
16
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5answers
5k views

Why plastic cases?

Early computers of the 'all in one' form factors, such as the Commodore PET, the early IBM microcomputers and later models of the TRS-80, as well as the 'box' form factors such as the Altair, used a ...
13
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5answers
2k views

Can the wrong sync frequency really destroy a CRT monitor?

I've read in various places that an incorrect signal of the wrong refresh rate can cause physical damage to a CRT monitor, but I've never found an adequate explanation of why this is so. Is this true? ...
6
votes
1answer
405 views

Testing RAM on a 386

I've got an old 386 laptop - specifically an OmniBook 300 - and I'm a little suspicious of the RAM. It's exhibited some very odd symptoms, such as memory-related crashes and boot failures, so I'd like ...
11
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3answers
1k views

What specific technical advance(s) allowed PCs to play “Full-screen full-motion” video?

In the early 1990s, the new buzzword for PCs was "Multimedia", and the gold standard for multimedia performance usually talked about was "full-screen full-motion" video playback. Many will remember ...
6
votes
1answer
212 views

Origin of the NZVC condition codes scheme?

The NZVC condition codes scheme, and corresponding set of 14 conditions for branches, is the nearly only in current ISAs that utilizes condition codes at all. The first computer I know that used it is ...