Questions tagged [hardware]

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

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14
votes
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 ...
54
votes
12answers
10k views

How big is a mainframe?

If you read about the history of computing, you'll hear how the first computers were "huge". You will often come across assertions that in the early days of commercial computing, a single computer ...
12
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2answers
527 views

BBC Master 65C102 co-processor — test memory

Out of the blue the other day, my friend found an internal 65C102 co-processor for the BBC Master in his attic, and gave it to me. It wasn't in particularly good physical condition (all the pins were ...
22
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10answers
4k views

Why was hardware diversification an asset for the IBM PC ecosystem?

The IBM PC was cloned very early on, and many third parties made hardware peripherals. This required users to run an OS, install drivers, manage IRQs and hardware bus addresses, etc. Why was this a ...
16
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6answers
3k views

What PC “Clone” technology standards were introduced by clone manufacturers?

IBM famously created the PC standard with the introduction of the first IBM PC in 1981. IBM also extended the standard with the introduction of the PC/AT (1984) and the PS/2 line (1987). However, by ...
21
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9answers
2k views

Why did CP/M and MS-DOS use the BIOS instead of their own drivers to access hardware?

Modern versions of Windows (and other modern operating systems I suppose) have their own drivers to access hardware. But as I have read, in the old days, if CP/M or MS-DOS wanted to access hardware, ...
2
votes
1answer
87 views

What's the required battery voltage within a DALLAS DS12C887+ RTC? [closed]

I am having some difficulty getting a board that has a Dallas Real Time Clock DS12C887+ to behave. Not sure if the problem is the RTC or not but am in the investigative stage and got the cross hairs ...
3
votes
1answer
291 views

First computer to have interactive text on a CRT?

What was the first computer to have interactive text on a CRT ? That the text on screen responded to key-presses without significant delay . I remember seeing some very early radar-installation CRT'...
24
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4answers
2k views

Why did so many early microcomputers use the MOS 6502 and variants?

Quite a few successful early microcomputers used the MOS 6502 CPU. This included, but was not limited to, systems like the Apple I, Apple II, Commodore PET, and Ataris. A followup known as the MOS ...
3
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1answer
108 views

how can I connect a scanner with Centronics 50 output to USB?

How can I connect a Legacy scanner with a Centronics 50 output to a laptop with USB ?
1
vote
1answer
89 views

Atari 1040STFM PSU Hissing, high pitch sound when on

I have an Atari, which is working correctly, but the power supply makes this hissing noise as soon as it is turned on. What may cause it?
8
votes
1answer
219 views

Anyone have more information on the “Hammerstein TV Games” 1st gen console?

I have what appears to be an early games console (supported games are variations on the theme of "pong", or ball and paddle games) manufactured in South Africa. Does anyone have more information or ...
8
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3answers
376 views

Why do Early DRAMs (e.g. 4116) have a negative Column Address Set-up Time?

Early DRAMs have a multiplexed address bus. Briefly speaking, to access a word, one needs to... Put the row address on the bus, and latch it using the falling edge of /RAS signal. Put the column ...
2
votes
1answer
117 views

Software Failure after RAM upgrade Amitek Hawk

I have Amitek Hawk for my A1200, the board came with wrong RAM and apps were crashing with 8003 Guru error. After contacting the seller I was told by mistake wrong SIMM was shipped and I received a ...
7
votes
1answer
773 views

What is this Amiga 2000 mod?

I got an Amiga 2000, board Rev. 6 Does anyone know what is is? (click to enlarge)
7
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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?
4
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3answers
165 views

How did console flexowriters connect to their computers?

Several early computers (e.g., KDF9, LGP30) used Friden Flexowriters for console functions. What was the nature of the connection between the Flexowriter and the computer? Was this something we ...
0
votes
3answers
306 views

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

What was the earliest date a home-computer or home-robot could be interfaced with a commercially available tv-camera or digital-camera . Although I'm asking this question for the purpose of computer-...
9
votes
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, ...
2
votes
0answers
138 views

Would anyone have made a mechanical, or electronic camera for their computer or robot? [duplicate]

Would anyone have made a mechanical, or electronic camera for their computer or robot ? Parameters Of The Question As a home-project [ Although, any example of a mechanical-tv-camera or mechanical-...
11
votes
1answer
486 views

What is this Amiga 1200 mod?

I got an Amiga 1200 off ebay and it works great, board looks perfect, no leakage, no bad traces, nothing, and yet I have this mysterious mod I've never seen before. Does anyone know what it is?
10
votes
3answers
829 views

Did Apple bundle a specific monitor with the Apple II+ for schools?

Sometime in 1980 (or maybe 1981) my school district purchased its first batch of Apple II+ computers. I remember vividly they had absolutely no idea what to do with them, and so the machines were ...
6
votes
2answers
495 views

Did any Apple II games use a “timing resistor”?

A science-lab program for the Apple II (I forget the name) had a board that plugged into the joystick port and included a "timing resistor". While I don't know what the program actually did with the ...
29
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9answers
9k views

How did early x86 BIOS programmers manage to program full blown TUIs given very few bytes of ROM/EPROM?

I've always wondered how so much functionality and relative luxuries(CMOS Configuration Utilities. See: https://geekprank.com/bios/ for an example) included with most popular x86 BIOSes could be ...
20
votes
1answer
2k views

Why was it possible to cause an Apple //e to shut down with SHIFT and paddle button 2?

Looking at the MAME driver for the Apple //e, I noticed an interesting comment: NOTE: On real IIe and IIe enhanced h/w, pressing SHIFT and paddle button 2 will short out the power supply and cause ...
2
votes
2answers
200 views

How exactly do all control signals in 6502 work?

I'm trying to make a 6502 replica in Logisim. I want to know what exactly each control signal in 6502, how the clock cycles work and additionally I would like to see an example of these control ...
4
votes
6answers
729 views

Was it possible to send data over the phone-line without a modem?

Was it possible to send data over the phone-line without a modem? Clarification Was it possible to send data over the phone-line without a modem, either by connecting computers directly to the ...
2
votes
1answer
113 views

can i build a colecovision ac adapter

Can I use multiple small AC adaptors to make a working Colecovision AC adaptor? For example, two 5V, one 12V and the ground. Colecovision AC adaptors are too expensive.
42
votes
5answers
15k views

Why did CPU designers in the 70s prioritize reducing pin count?

A lot of 70s era microprocessors were packaged in DIP packages with 40 pins. This was a reasonably good fit for 8-bit processors: 16 address lines, 8 data lines, 2 power and clock are all absolutely ...
9
votes
1answer
268 views

How did the Zip Chip and RocketChip accelerators work for the Apple II?

Though there is already a similar question on the site, this one is more specific to these chips and their technical implementation. There were two accelerators for the Apple II series that were drop-...
33
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6answers
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. ...
43
votes
5answers
15k views

What did the 'turbo' button actually do?

I remember the computer I played Commander Keen on as a child had a turbo button that I was forbidden to touch, what did this button actually do?
11
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4answers
274 views

Preventing socketed chip corrosion?

I spent a couple hours repairing an Amiga A3000 that wouldn't boot yesterday. The fix was to remove Kickstart ROMs, clean the DIP leads and sockets with contact cleaner, and re-insert. Apparently a ...
11
votes
3answers
4k views

When did game consoles begin including FPUs?

Floating-point coprocessors (FPUs) were an expensive, niche, add-on product for early desktop and home computers. but became commonplace by the mid-1990s, as they began to be included within the most ...
19
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7answers
1k views

Separate code and data address spaces on the Z80

Reading through the Z80 datasheet, I noticed something interesting. The Z80 separates its instruction execution into separate phases (which are called "machine cycles" in the official literature, but ...
4
votes
0answers
80 views

Backlight inverter failure on TI Travelmate

I picked up a TI Travelmate 4000E for free and it worked perfectly using my AC adapter(genuine TI one from another 4000E). The backlight fires up full brightness for about a second, then dies. ...
14
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 ...
13
votes
2answers
974 views

What was the design of the Macintosh II's MMU replacement?

I am in the process of repairing a Macintosh II and trying to understand the design rationale behind Apple's MMU replacement part installed in this machine. As you can see in the picture, there is a ...
1
vote
1answer
254 views

Refactoring Old Printer Driver for Current Linux Kernel [closed]

I have an old Lexmark 1100 printer (parallel port LPT1) that is currently working fine on Windows 98. I've tried to make it work on several current distros of Linux but, so far, none worked. Basically,...
12
votes
1answer
1k views

Number of transistors in the C64

How many transistors are there approximately in the C64 if we consider every chip on it? I think that it is something around 50.000 but I'm not sure.
28
votes
1answer
2k views

How do Amiga 600 CPU accelerators work?

The Amiga 1200 has a trapdoor expansion for CPU accelerators. The Amiga 500 has a side expansion port and its CPU is socketed. But Amiga 600's expansion port is only useful for memory expansion ...
26
votes
6answers
5k views

Why weren't discrete x86 CPUs ever used in game hardware?

Please don't point out APUs with x86_64 cores used in current generation game consoles, these are not part of the question I cannot recall a single arcade system or game console that ever used x86 ...
3
votes
1answer
168 views

IBM 650 - how many logic gates?

How many logic gates did the IBM 650 have? I'm used to measuring the complexity of a CPU by transistor count, but the 650 was a vacuum tube machine; the number of tubes would also be an interesting ...
44
votes
2answers
5k views

Why did the IBM 650 use bi-quinary?

The IBM 650, announced in 1953, was the world's first mass-produced computer. It represented numbers in decimal, which is understandable, both because it needed to work with exact money amounts, and ...
13
votes
3answers
2k views

Is it possible to expand Amiga 500 rev 8 to 1.5 MB with a 1MB trapdoor expansion?

Is it possible to expand an Amiga 500 rev 8 (not an Amiga 500 plus) to 1.5 MB of Chip RAM using an A501+ expansion? It is plug and play or are modifications required? This is the board: Source: ...
6
votes
2answers
224 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 ...
12
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3answers
3k views

What is the benefit of increasing Amiga chip memory?

For example, an Amiga 500+ has 1MiB of chip memory, but it can be expanded to 2MiB. What would be the advantage?
27
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1answer
2k views

What are the Amiga 1200 timing fixes?

I have read that the Amiga 1200 may need certain "timing fixes" to be applied to the motherboard in order to use CPU accelerators. What are these timing fixes and why are they needed? Is there one ...
4
votes
6answers
3k views

Were any external disk drives stacked vertically?

There was a time when floppy disk drives were big, expensive devices that in many cases, instead of being components of a computer, would be separate machines connected by a cable, in some cases with ...
13
votes
1answer
643 views

What is the Kelly chip?

The Amiga 3000+ DevCon 1991 notes says: On the A3000+, these resources include the Amiga "Pandora" chip set (Alice, Lisa, Kelly, and Paula), However, a Kelly chip is not part of the official ...