rackandboneman
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What were the 9 VAC pins used for on the Commodore 64 User Port?
5 votes

Possible uses would have been for any peripheral that needed: Its own low-noise voltage regulated power supply (eg ADC/DACs for measurement and control, or audio stuff) A symmetric power supply for ...

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Why do programmable sound generators like SID include a noise generator?
5 votes

There are many acoustic events - drum beats, steps, explosions, breath, abrasion, clicking... that are based on a lot of harmonically unrelated frequencies in relatively irregular patterns. Which is ...

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What is the first (say early) use of switches (mechanical or electromechanical) for sake of processing (like automatic motor control)simple data?
4 votes

Maybe not the earliest, but early and important, and very elaborate uses: Automatic telephone exchanges. Strowger, 1891. Elevator control (early 20th century). Telegraphy, especially teleprinters (...

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Why did trackballs disappear?
4 votes

One disadvantage is that they are hard to use for users that prefer using a mouse at high acceleration and with the wrist resting - of course using it with a fingertip like a mouse wheel is possible, ...

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What was the first personal computer to use surface mount components?
4 votes

The Epson HX20 from 1981 uses an LCD module which uses surface mount driver ICs.

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Why did the IBM PC need a sound card?
4 votes

One major thing the builtin sound hardware lacked was any facility to input/record (but so did the very first IBM soundcard, which was more or less a Yamaha FB-01 on an ISA card).

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Run 8086 programs in dos using simple os other than any special software
4 votes

Assuming your question is about working with 8086 assembly language programs, without using third party software. Look at the DEBUG.EXE program that is part of all practical MS-DOS distributions -it ...

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Primary manufacturers of picture tubes for early monitors
Accepted answer
4 votes

I know links as answers are frowned upon. But this official document called "Color Picture Tubes from Canada, Japan, the Republic of Korea, and Singapore" by an US commission has more on both US and ...

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Original Mac capacitor inspection
4 votes

A few generic things to know when proactively replacing electrolytic capacitors: There are at least two measuring devices you need to truly test electrolytic capacitors - a capacitance meter and an ...

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Computers with integrated monitor (all-in-one form factor)
4 votes

Indeed, the PET likely took a lot of design ideas from "dumb" (actually semi-intelligent - very few of these weren't simple microcomputers inside!) terminals of the 70s, and kept the non-detachable ...

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Commodore Mouse not recognized by a Commodore PC30-III 286 machine
3 votes

In the age of serial mice, there were two completely incompatible standards that most mice emulated (many had a physical switch to select either of both, eg the popular Genius brand mice) - "...

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Why did 8-bit computers choose BASIC dialects as "de facto" command-line interface, instead of contemporary Shell/Lisp dialects?
3 votes

Unix-style shells are optimized for environments with a lot of files in a relatively stable and fast to access, but complex structure - essentially, shells are programming languages that use files and ...

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How were bugs reported for compilers that were shipped on floppy disks?
3 votes

The fast and noisy bug-fixing, constantly-updating ecosystem we know today has only become popular in the mainstream somewhere in the 90s, probably coming from the open source community. Testing for ...

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Part-bad chips other than RAM
3 votes

Intel very likely did this with surplus batches of ROM-equipped microcontrollers - eg if you look closely at the pinout of the 8031 vs 8051/8751, an 8051 wired up like an 8031 WILL behave as an 8031 ...

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When did computers stop checking memory on boot?
3 votes

Certainly not before standards for RAM enumeration (SPD serial presence detect) were introduced (with the SDRAM 168pin form factor). Earlier systems needed the memory check to established what memory ...

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Why did Windows 95 crash the whole system but newer Windows only crashed programs?
3 votes

Addendum: Some special memory areas (eg the infamous "GDI resources") that all applications needed were extremely limited in size (due to being shared with 16-bit APIs, which needed segment size ...

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Total number of 6502s or 8051s ever manufactured or sold?
3 votes

Regarding the 8051: One in most OSD-capable CRT monitors or television sets ever sold. One in most pre-DVD CDROM drives ever sold. One in most pre-2000s hard drives. A predecessor of the 8051 (the ...

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Why plastic cases?
3 votes

Another reason: Simple home computers used relatively slow (both in risetime and in clock frequency) circuitry which was also contained in a relatively small area (making the wiring a less effective ...

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Where are the memory controllers for IBM 5150 or Altair 8800?
3 votes

The actual CPU bus (which would be called the "frontside bus" on 686-era designs) on the 8086, 80386, 68000 and similar CPUs IS more or less a memory bus. Typical peripheral chips (UARTs, floppy ...

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When did the tower form factor appear and when did it become popular?
3 votes

PC specific, ignoring non-PC systems here. Remembering early-90s systems, 286 machines were mostly built in the "Baby-AT" form factor. Sometimes you still saw new 286/rarely 386 builds in the full-...

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Can a retro-computer be a useful way to learn computer-architecture fundamentals?
3 votes

Yes, and countering the "still a black box" argument. Hardware on the level of the original IBM-PC or AT is accessible as an electronic system to someone with "some" electronics skills and affordable ...

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80s DRAM chips: one per bit of data bus width?
3 votes

One other reason: 1-bit chips could easily be configured as 8 or 9 bit wide arrays using only one type of chip - the latter in cases where memory parity (error checking) was desired. Sometimes, 4+4+1 ...

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ZiLOG Z80 fan-out (CMOS version, Z84C0006PEC)
3 votes

74xx245 are cheap and/or can be salvaged from computer scrap (if you are capable of desoldering) in large amounts. Unless you are driving TTL circuitry, the reason you want a buffer is more about ...

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What was the first operating system to feature a separate kernel?
3 votes

Even an OS kernel on a some very modern system (certainly compared to what is relevant here) uses "special memory values" and machine dependent hacks to provide an ABI. https://stackoverflow.com/...

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Where can I find an external 8-inch floppy disk drive?
3 votes

Be aware that there were several incompatible formats around when 5 1/4 and 8 inch floppy disks were in use - see https://en.wikipedia.org/wiki/List_of_floppy_disk_formats. Incompatible as in, the ...

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How to detect a real Commodore 64, THEC64, or VICE emulator in software?
2 votes

One thing that can give emulators away (not reliably, but it might be good enough in practice) is how predictable the results are when you do something that is supposed to yield an undefined result. ...

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Retrieving text documents from a 2.0 MB/2.0 HD floppy disk?
2 votes

On floppy media that was not sold as preformatted, the unformatted capacity was commonly stated. ~2 MB is the unformatted capacity of what is commonly called a ‘1.44 MB’ floppy. However, the actual ...

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Why did computer video outputs go from digital to analog, then back to digital?
2 votes

Cabling costs, for one thing. An 8 bit per channel digital link capable of reliably handling tens of MHz, in the late 1980s/early 1990s, would have looked similar to Wide SCSI in physical ...

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Steps to recover data from Conner CP341
2 votes

From another good answer: "Connecting it to a PC where you can manually set the drive parameters in BIOS is the fastest solution." Hint for finding such a PC: The facilities to manually set such ...

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How to at least partially read damaged sectors of floppy disk?
2 votes

If the actual task at hand is recovering such data at any cost and effort, there is still the possibility of directly recording the read head signal on some recording and visualization device, eg a ...

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