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Questions tagged [hardware]

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

2
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2answers
244 views

How significant/pioneering was the TV Typewriter?

How significant and pioneering was the TV Typewriter, in light of things like calculators with CRT's from 1964 and various other things? I recently read that the TV Typewriter established the standard ...
3
votes
1answer
132 views

Ways To Test iMac G3 Before Buying

I am going to buy an old iMac G3 Over the next couple of days/weeks, and I want to make sure that I am buying a system with no problems. I usually ask for the serial number and good pictures before ...
7
votes
3answers
721 views

what OS runs Zip drives? [duplicate]

I came across my old Zip drive and some Zip disks. I am curious what is on the disks, but my Windows system won't run them. Back in the day I thought that these would be the ultimate in archive ...
8
votes
4answers
2k views

Purpose of two disk drives on the Osborne 1

I recently discovered the Osborne 1 computer, and I noticed it had two floppy disc drives. What was the purpose of including two drives?
4
votes
4answers
423 views

What is the basic logic behind the setting or ordering of keys in a keyboard?

I am a computer science student. I mostly work with computers and I am really wondering about the layout of keys in a keyboard. It is comfortable and easy. My question is this: what is the basic ...
4
votes
2answers
407 views

What's with the empty space on this die?

Here is the Valvo 2650. (Also known by other names, in the UK as Signetics 2650). What struck me about this image is the amount of empty space! If you look at a modern-day chip, say a Skylake or ...
4
votes
0answers
105 views

Is there a comparative analysis of the evolution paths of chips inheriting from TMS9918?

This is primarily about VDP from the Sega Master System game console and video chip from the MSX 2 series computers. Specifically about Yamaha YM2602 (aka Sega 315‑5124) and Yamaha V9938 respectively. ...
17
votes
2answers
3k views

Reason for gold lines on old ICs?

A lot of older (ceramic) ICs have a gold-plated line extending from the die cover to the edge of the package. Did this serve a practical purpose or was it just bling? I suspect that it might be what'...
31
votes
5answers
6k views

Using DRAM as a camera sensor?

Back in the days when COMECON (RVHP) was cloning digital ICs usually the first wave of such ICs were in a ceramic package with a glass window (similar to EPROM) to check for bugs and stuff while used. ...
0
votes
3answers
156 views

The earliest a home-computer or home-robot could be interfaced with a camera

What was the earliest date a home-computer or home-robot could be interfaced with a tv-camera or digital-camera . Robots were often based on home-computers . Although I'm asking this question for ...
40
votes
17answers
6k views

Simplest system to create an emulator for

Next year I'm going to teach a 2-semester microprocessors class to third-year undergraduate EE students. In order to sign up for the class, students need to have completed programming and digital ...
5
votes
2answers
238 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
195 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
votes
4answers
523 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
votes
1answer
181 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 ...
14
votes
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
235 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
votes
1answer
475 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 ...
3
votes
2answers
175 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
votes
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....
10
votes
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 ...
8
votes
1answer
179 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
votes
3answers
488 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 ...
7
votes
1answer
366 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 ...
2
votes
3answers
220 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 ...
2
votes
5answers
627 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
votes
5answers
2k 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 ...
8
votes
2answers
339 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 ...
1
vote
0answers
171 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
257 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 ...
6
votes
3answers
352 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 ...
43
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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 ...
3
votes
2answers
157 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 ...
10
votes
4answers
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, ...
10
votes
4answers
962 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 ...
13
votes
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
votes
5answers
346 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 ...
6
votes
0answers
251 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 ...
8
votes
1answer
351 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 ...
23
votes
4answers
4k 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
votes
2answers
272 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 ...
6
votes
2answers
2k 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?
3
votes
3answers
370 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
votes
4answers
790 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 ...
1
vote
1answer
470 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)....
25
votes
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
votes
0answers
185 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
vote
2answers
231 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 ...
0
votes
2answers
183 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 ...
8
votes
2answers
370 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 ...