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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18
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2answers
4k views

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
224 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 ...
5
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2answers
830 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 ...
21
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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 ...
3
votes
2answers
172 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
206 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
138 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 ...
8
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1answer
828 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
202 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 ...
10
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10answers
3k views

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
374 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
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1answer
184 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
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3answers
281 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
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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
258 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
465 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
133 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
220 views

Vector-06C Soviet home PC schematics

Looking for Vector-06C schematics in any form.
5
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2answers
238 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 ...
4
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1answer
333 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
750 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
224 views

Killer poke on the Ninendo DS via POWCNT1 register

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) (...
17
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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
199 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 ...
2
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1answer
161 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 ...
1
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1answer
322 views

What to do with stone age x86 computers? [closed]

Not sure if retro is proper place... I have two old notebooks with x86 processors in the 100s range of MHz. While nostalgics might appreciate them, I'm wondering if there is any proper point in ...
2
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2answers
314 views

What was the DRAM refresh interval on early microcomputers?

Dynamic RAM is denser than static RAM, but needs to be refreshed every few milliseconds to avoid losing data. How many milliseconds, exactly? If the answer has changed over time, then I'm interested ...
3
votes
1answer
390 views

Did the Nintendo S-SMP really contain 3 million transistors?

According to http://www.vgmpf.com/Wiki/index.php?title=S-SMP The S-SMP (perhaps: Sony - Sound & Music Processor?) is the audio CPU used by the Super Nintendo Entertainment System. It consists of ...
6
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1answer
228 views

Player 1 / Player 2 input for Space Invaders

According to the Computer Archeology page on Space Invaders, port 1 presents "player 1's shoot/left/right" input to the CPU, whereas port 2 presents player 2. Playing around the code in an ...
3
votes
1answer
241 views

Why did the Vic-20 need special chips for I/O?

The Vic-20 used two 6522 VIA chips for I/O. I asked why it had two of them but thanks to a comment from Bruce Abbott, I now think that wasn't quite the question I needed to ask. What I really need to ...
3
votes
1answer
649 views

Why does the Vic-20 have two VIA chips?

The Vic-20 uses the 6522 VIA for peripheral I/O. However, it has two of them. I find this surprising, particularly considering minimizing cost was an important design goal. Is there a reason why it ...
5
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3answers
436 views

What is the difference between the 6522 VIA and a UART?

The 6522 VIA is an I/O chip used in the Vic-20. I was under the impression that UART (Universal Asynchronous Receiver/Transmitter) is the general term for such chips, so was surprised to see this: ...
20
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11answers
5k views

Did any European computers use 10-line fonts?

Most 8-bit computers implemented hardware text mode, and most of those used 8x8 fonts. This was logical for American computers; the title safe area on NTSC is about 200 scan lines; font height 8 gets ...
7
votes
4answers
2k views

Could any computers use 16k or 64k RAM chips?

An interesting feature of the Apple II was that it had three rows of sockets for RAM chips, each of which could take either 4k or 16k chips. That meant the minimum configuration was 4K (cheap) but it ...
2
votes
1answer
103 views

Macintosh IIci not booting

I have an old Macintosh IIci that worked until a few weeks ago but now doesn't turn on anymore. When I press the power button on the keyboard all the lights on the keyboard and the one on the main ...
16
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2answers
2k views

Why did the 8087 need a special socket?

The IBM PC included a coprocessor socket for the 8087 floating-point unit. Logical enough; some customers wanted to use the 8087 to make numeric calculations run faster. But why was the 8087 designed ...
20
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5answers
5k views

Why did mainframes have big conspicuous power-off buttons?

Some fascinating stories in this discussion thread. It starts with discussion about computers overheating, but about halfway through the thread, it switches to discussion of mainframe installations in ...
3
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0answers
144 views

Why did Gran Trak 10 cost so much?

In 1974, Atari released a driving game called Gran Trak 10. The development prototypes had used real car steering wheels and pedals, but it was realized these were too expensive, so they were changed ...
3
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2answers
473 views

How did wave soldering work? [closed]

While it is not used as much nowadays, wave soldering was a big advance in the productivity of manufacturing electronics, compared to soldering all the components by hand. It consists of placing all ...
19
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8answers
4k views

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 ...
12
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4answers
903 views

Did the Commodore datasette interface provide greater reliability?

Cassette, being cheaper than a floppy disk drive, was a popular storage medium in the 8-bit era. Some computers such as the Sinclair Spectrum, just provided a port to plug in an existing cassette deck....
9
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2answers
695 views

Did any 8-bit CPUs use dynamic memory for registers?

According to https://jamiestarling.com/project-8088-the-8088-cpu-pinout/ One thing to note – the 8088 registers are made from dynamic memory cells – they have to be refreshed. The minimum clock speed ...
3
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2answers
266 views

Could the 6502 have worked with an Altair-style front panel?

I have fond memories of programming the 6502, though I never did any hardware hacking with it. I notice that the Altair, with its iconic front panel, was based on the Intel 8080, and from then on, ...
18
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1answer
3k views

What is the function of this strange IBM apparatus?

Does anyone know what kind of device this is? I found it in my late dad's stuff, probably from the 1970s. It has no number, type, model, serial number or anything else on it that could be used for ...
2
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1answer
115 views

Intel vs Motorola device communication protocols

On this page about "An S-100 68000 CPU Board" it is said: From a hardware perspective there are some very significant differences how Intel and Motorola CPU's talk to the world. Somewhat ...
1
vote
1answer
152 views

Why was the SWTPC 6800 Computer System cheaper than the Altair?

In 1974, Intel released the 8080, which basically was the first microprocessor good enough to build a serious computer around. That led to the Altair 8800 the following year, which was the beginning ...
37
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2answers
4k views

Was AGP only ever used for graphics cards?

Reading on the AGP spec, the little bits I've found on sites like https://old.pinouts.ru/Slots/agp_pinout.shtml, say: The Accelerated Graphics Port (also called Advanced Graphics Port) is a high-...

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