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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11
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3answers
1k views

Does 10BASE-T need more sophisticated electronics than 10BASE5/10BASE2?

In a discussion on the history of Ethernet and 10BASE5, Stefan Skoglund commented Was 10BASE5 a mistake? One reason why 10BaseT became possible is Moores law (and the same for the other designs after ...
6
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4answers
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What was the first Ethernet hub?

An Ethernet hub is – well, Wikipedia does an impeccable job of summarizing what it is: An Ethernet hub, active hub, network hub, repeater hub, multiport repeater, or simply hub is a network hardware ...
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5answers
6k views

Was 10BASE5 a mistake?

https://en.wikipedia.org/wiki/10BASE5 gives a succint but vivid description of the physical layer of the first version of Ethernet and its subsequent replacement: 10BASE5 (also known as thick ...
25
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3answers
4k views

When did 5.25″ floppies exceed the capacity of 8″?

When 5.25″ floppies were introduced, in the mid-to-late seventies, they would have had less capacity than the older 8″ because, well, less area on which to store data. On the other hand, being cheaper ...
22
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4answers
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Why did the TRS-80 CPU have priority over the display?

The original TRS-80 had a separate bank of static RAM for video memory, so that there would be no interference between display and CPU when the CPU was just doing calculations in main memory. When it ...
33
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4answers
5k views

Why was manual branch suggestion abandoned?

Once pipelined CPUs became common, a common issue arrived as a result of taking the wrong branch of a conditional jump, and thus needing to flush the pipeline. As a result branch prediction mechanisms ...
12
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1answer
2k views

What is purpose of the “CH” button and “CH” switch position on this calculator?

What is purpose of the CH button and CH switch position on the Omron Elite 8002 Taschen-Rechner? (For those who don't know German, “Taschen-Rechner” just means “calculator”.) The switch has three ...
7
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2answers
202 views

How did Apple IIc daughtercard expansions work?

I've been doing a lot of reading about the ways Apple IIc owners expanded their machines in the absence of the IIe's slots, and it's very intriguing stuff. The ones that I'm most curious about are the ...
5
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1answer
197 views

What was the first control display unit with selector keys around the display?

If not the first, then the one that became popular first (in any application; this is not limited to aviation systems). A control display unit, CDU for short, is fairly common in aviation, perhaps ...
5
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1answer
284 views

What kind of graphics hardware did Nichibutsu's 1985 arcade game "MagMax" use?

The arcade game MagMax by Nichibutsu came out in 1985 and features for its time an impressive 3D scrolling effect which, in my observation, is not widely discussed yet, although it should be ...
6
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1answer
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What was the price of a Winchester-Drive for the HP-85 desktop computer back in 1980?

I wrote my first computer programs in HP-Basic on a HP-85 desktop computer. The year was 1980 and we stored our programs on special "high-speed" cassette tapes. I remember proposing to buy a ...
15
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4answers
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How was the real-time clock implemented in the original IBM PC and PC/XT?

I know that the IBM PC/AT added a battery backed real-time clock chip that independently maintained time whether the system was powered or not. I've also seen many of those big DS1287 clock chips on ...
26
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3answers
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In what ways was the Soviet STRELA computer "designed to function during a nuclear winter"? Or at least parts of it?

From Strela computer: Strela computer (Russian: ЭВМ Стрела, arrow) was the first mainframe computer manufactured serially in the Soviet Union, beginning in 1953. This first-generation computer had ...
4
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1answer
122 views

Quadram odd IBM PC card bracket

I came across an early IBM PC ISA realtime clock/calendar card made by Quadram called the "Chronograph" (picture). It's basically the same clock feature they incorporated into their ...
7
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1answer
493 views

Did the original Japanese Tamagotchi device really die *completely* (forever) if the digital pet died? [closed]

Ever since 1997, I've had this "factoid" in my head that the original release of Tamagotchi in Japan had no "reset" feature, and you could not remove the batteries to reset it ...
10
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2answers
382 views

How do I terminate an ISA bus correctly?

I am stuck by designing a 8 Slot 16 Bit ISA Backplane Do I have to terminate an ISA bus? My search results are: No termination at all Some homebrew projects use active termination for all signals ...
1
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2answers
163 views

How many kinds of mass-producible ROM is avaliable before 1970? [duplicate]

Back in the days before mask ROM (when invented?) we got core rope memories, or Little Old Ladies memories, which required lots of human labor to build. Were there any kinds of ROMs which were ...
14
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1answer
606 views

Why did the Rumble Pak for the Nintendo 64 require batteries when it actually apparently doesn't?

After watching this video tutorial: https://www.youtube.com/watch?v=AyJsOoQKRjQ I'm wondering what the whole deal was with the batteries. Apparently, you can resolder the circuit board inside the ...
4
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3answers
469 views

Were there low-end eighties computers that used dual-ported video RAM?

Going through schematics of several home or small office computers of the era, I was wondering why almost none of them (1) used dual-ported video RAM. I understand that those chips were initaly ...
0
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2answers
179 views

Z80 - "LD (nn), dd" command cycle [closed]

For a university assignment, I have to describe and draw the command cycle of the LD (nn), dd command. To be exact, I was given this command: LD (0x1000), BC which I interpret as putting the low ...
10
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2answers
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Did the PDP-8 designers consider a stack?

The PDP-8 was a remarkable exercise in minimalist computer design; some of the aspects of its design are discussed in detail at PDP-8 transistor count One feature it did not have was a stack. Instead, ...
21
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3answers
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What was the rationale behind 32-bit computer architectures?

Though today various power-of-2 word sizes seems to be the norm, back in the 50-60s multiple-of-6 word sizes was more popular and was required by Department of Defense(DOD) in particular. 36-bit ...
27
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2answers
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How did the "Programmer's Switch" work on early Macintosh Computers?

The early Apple Macintosh computers (original Mac, Mac 512K, Mac Plus) all came with a "Programmer's Switch" installed on the side. I believe this persisted for a long time, with the switch ...
5
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2answers
469 views

How can I tell if my old PC supports > 137 GB hard drives?

I have an old PC from 1999 that has an ASUS P5A motherboard. When I power it on, it says ASUS P5A ACPI BIOS Revision 1011 Beta 005 and 05/02/2002-ALADDIN5-<<P5A>>: I recently read that up ...
6
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2answers
983 views

Were any vacuum tube computers built with wire wrap?

I'm trying to gain some understanding of how early computers were built; as discussed in What accounted for the cost of ENIAC? the cost of first-generation computers was not necessarily mostly about ...
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4answers
4k views

What accounted for the cost of ENIAC?

I'm used to the fact that first-generation computers were very expensive, which I had always assumed was because they contained large numbers of vacuum tubes, each of which is a rather complex, high ...
4
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2answers
273 views

How many 6SN7 tubes did it take to store a bit?

One of the most important components of a computer is a circuit called a flip-flop, which has two stable states (that it can flip-flop between, hence the name); it is used for temporary storage of a ...
1
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1answer
279 views

8088 CPU A16-A19 address lines go crazy with nop test after 0FFFF address

I'm building a minimal, minimum mode 8088 computer. I started with an 80C88-2 (CMOS, static variant) CPU. My configuration is really simple. One CPU, one 74HCT245 (DTR->DT/R) for the data lines, ...
3
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2answers
178 views

Could early computers use existing punch card machines?

In the early decades of the industry, computers used punch cards for data storage and transmission, partly because they were already widely used for pre-computer data processing; indeed, a major ...
9
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1answer
861 views

How many transistors in the CDC 1604?

The CDC 1604, released in 1960, was Seymour Cray's first supercomputer, and also one of the first computers made of transistors. (The IBM 7090 was released only the previous year.) How many ...
5
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0answers
240 views

Were vertical monitor arcade games programmed differently from those with horizontal monitors?

Many classic arcade games like Pac Man (Namco 1980), Assault (Namco 1988), Mercs (Capcom 1990), etc, use a monitor oriented vertically. I assume that they used the same physical hardware, with the ...
11
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10answers
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Hardware assisted Graphical User Interface?

I have read a fiction novel in which a manufacturer in the 80s provided GUI by adding a dedicated drawing hardware besides videocard or by extending videocard. Fictional as it is, is this possible or ...
12
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2answers
2k views

How did the Altair ensure that the −5 V supply was the first connected and last disconnected?

The Wikipedia page for the Intel 8080 processor describes pin 11 as The −5 V power supply. This must be the first power source connected and the last disconnected, otherwise the processor will be ...
2
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2answers
406 views

How were the popular CPUs of the eighties implemented? [closed]

With the ubiquity of FPGAs, I find it relatively easy to design an eighties-like CPU. But it's maybe too simple now, with so many ways to implement any given CPU unit. What were the hardware ...
6
votes
1answer
221 views

What were the different RAM refresh techniques in the 80s

I've looked at some techniques that were used at the beginning of the eighties to refresh the RAM (CPU-based refresh for the Z80, or the use of the video circuit for computers that shared the bus ...
19
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2answers
1k views

How did the Apple IIGS automatically slow 5.25 inch disk I/O code for backwards compatability?

Apple II software often used hard-coded timing for 5.25 inch floppy disk I/O, for example to control the duration of each track step or the rate at which bytes are written and read from the disk. ...
13
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4answers
3k views

CPU frequency / memory wait states at end of the 80s

According to the advertisements of the late eighties, you could find RAM having an access time ranging from 120 to 80 ns (150 to 210 cycle times). A 386SX-25 could execute a typical register to ...
-4
votes
3answers
318 views

What was the last personal computer to have the chips neatly arranged in rows and columns?

Once upon a time, the chips on the circuit boards of personal computers1 were arranged in a tidy grid pattern. Observe the board of the Apple ][+: Or the Commodore 128: Sadly, the zen of neat rows ...
6
votes
1answer
1k views

What was the first computer board to be wave-soldered?

The Wikipedia article on wave soldering does not give any information on its history. What was the first computer circuit board to use this process? I am specifically looking for computers that were ...
1
vote
1answer
274 views

Which Mac models included a software visible DSP chip

Which Mac models included a DSP chip that could be accessed by regular application code? (e.g. not hidden inside the mouse, WiFi chip, disk read/write chip, GPU, etc.) Did they ship before or after ...
-3
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3answers
487 views

Were there ever plans published, or kits, or a machine made, for a noughts-and-crosses computer game which did not use electronics? [closed]

Were there ever plans published, or kits, or a machine made, for a noughts-and-crosses computer game which did not use electronics – using only wire, an electricity source, and light bulbs ? . A ...
3
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1answer
156 views

How do I setup this Kickstart switcher?

I can not find any documentation for this Kickstart switcher. It's labeled LS A9211-3 © FH 1992. How must the jumpers J1 and J2 be set and where must the KB and RES lines be connected to? I want to ...
0
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2answers
248 views

Vector-06C Soviet home PC schematics

Looking for Vector-06C schematics in any form.
5
votes
2answers
261 views

Config information on ancient 16-bit Multi I/O card

I need to build a retro machine so that I can access an HDD that required manual input of BIOS parameters. (Yes, I have that information.) The only ID I can find is ES1O/4A 280695 which yields nothing ...
5
votes
1answer
515 views

What's wrong with SNES original controller's shoulder buttons?

This is probably a hardware-related question. I have recently bought a total of 7 (seven) different original SNES controllers from different sources, all of them being somewhat used but mostly ...
10
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2answers
803 views

When does an IBM-compatible PC keyboard controller dequeue scancodes?

There is a not-unheard-of technique in DOS software to detect certain keypresses (like Ctrl+Break) by intercepting the keyboard interrupt (IRQ 1) and reading the scancode directly from the keyboard ...
9
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0answers
387 views

How would toggling a bit in the POWCNT1 register cause hardware damage on the Nintendo DS?

From GBATEK, writes to a certain I/O port for power management may damage hardware: 4000304h - NDS9 - POWCNT1 - Graphics Power Control Register (R/W) 0 Enable Flag for both LCDs (0=Disable) (...
18
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1answer
1k views

How did the Nova 1200 divide so quickly?

According to https://en.wikipedia.org/wiki/Data_General_Nova The Nova 1200 executed core memory access instructions (LDA and STA) in 2.55 microseconds (μs). Use of read-only memory saved 0.4 μs. ...
8
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2answers
235 views

Why was the VT05 resolution 72×20?

According to https://en.wikipedia.org/wiki/VT05 the VT05 presented the user with an upper-case only ASCII character display of 20 rows by 72 columns. At first glance this seems a reasonably natural ...
5
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2answers
540 views

Modern heat sinks for Commodore C64/C128

The VIC-II and SID chips in the C64/128 are prone to over-heating and are rather expensive to replace nowadays. Some other ICs in these machines may have the same issue. An unmodified machine includes ...

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