Questions tagged [hardware]

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

Filter by
Sorted by
Tagged with
7
votes
3answers
259 views

What are the Ultra-Highres registers in ECS and AGA for?

The Amiga custom chip set, in its ECS and AGA versions, seems to contain some registers for what is called an "Ultra-HighRes/DUAL" mode: DFF078 SPRHDAT W Ext. logic UHRES sprite pointer and ...
5
votes
9answers
1k 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 ...
1
vote
3answers
223 views

When was Tantalum first used in computing?

I know that nowadays Tantalum is very common in computer components, specifically capacitors, due to its desirable electrical properties. I'm curious when it was first used specifically in the ...
14
votes
6answers
1k views

How much data could a home computer store on an audio cassette?

The use of audio cassettes for storing data for home computers was a great example of repurposing an existing invention. Cassettes were sold in a variety of capacities, and labelled with their audio ...
2
votes
0answers
166 views

Reference material for building a DIY Stack Computer from Logic Gates

I've been following Ben Eater's series of videos about designing a small computer from discrete logic gates, I'm curious if there is a similar tutorial/book/reference for building a stack computer. I ...
7
votes
2answers
458 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'...
7
votes
3answers
593 views

What were the first chips with hardware support for SPI?

The SPI four-wire serial bus is a very common interface between chips and other small devices these days, but was originally developed by Motorola in the mid-1980s. What were the first Motorola and ...
10
votes
1answer
250 views

How did restarts resolve parity errors triggered by broken core-rope wires?

In his account of the history of the Apollo Guidance Computer, Don Eyles describes the role of a parity bit as follows (p. 80): ... if one of those hair thin wires in our woven core-rope memory ...
12
votes
3answers
347 views

Pair Am386 with i387

I've got a motherboard with a Am386/DX processor. I've also got an Intel 387 coprocessor. Is it possible to use the Intel 387 that I've got together with the Am386 or do I need a coprocessor from AMD?...
8
votes
6answers
722 views

Low-cost sound chip

I want to make a homebrew 8-bit computer and I want to include a sound chip in it. It needs to be as cheap as possible (under 5$) and I also want it to be possibly controlled by an Arduino or ATmega-...
9
votes
2answers
531 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 ...
4
votes
1answer
109 views

Was there any VIC-20 expansion to bring memory beyond the default maximum of 40 KiB?

The Commodore 64 was very flexible in terms of how RAM could be controlled. ROMs and I/O devices could easily be swapped out by setting bits in the first two addresses of memory. The VIC-20's ROMs and ...
6
votes
2answers
1k views

Why have computers used so many different video connectors? [closed]

Over the years and with the large variety of hardware I've dealt with I've used quite a few of different video inputs and outputs. While I usually have no issue just plugging cables into devices, I ...
16
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 ...
55
votes
12answers
11k 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 ...
13
votes
2answers
556 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
votes
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
votes
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
votes
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
90 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 ...
24
votes
4answers
3k 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
votes
1answer
111 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
98 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
230 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
votes
3answers
387 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
124 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
785 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
votes
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
votes
3answers
173 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
319 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
144 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
492 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
846 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
498 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
votes
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
214 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 ...
2
votes
1answer
117 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
294 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
votes
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
votes
4answers
282 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 ...
12
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
votes
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
999 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
266 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,...