Questions tagged [hardware]
Retro hardware generally: boards, extension cards, power supplies, peripherals. Use more specific tags as appropriate; use [case] instead for enclosures.
581 questions
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Did any notable 6502 systems coordinate DMA with start of instruction rather than adding delay for possible writes?
An annoying hardware quirk of the 6502 is that while the READY line can be used to extend read operations, it cannot be used likewise for writes. As a result, systems which need to accommodate DMA ...
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How to remove end of snapped ZX Spectrum keyboard connector
I recently powered on my 48k ZX Spectrum (1983 Issue 3B), and the keys 1-5 were not working. I decided to open it up to see if reseating the keyboard connectors would solve the problem. Unfortunately ...
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Maximum number of sprites per scan-line on Ghosts'n Goblins Arcade Hardware?
I'm working on a project that targets the Capcom PCB for Ghosts'n Goblins. According to the information available from the schematic and MAME the hardware support a total of 128 sprites on screen and ...
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CD with physical hole is perfectly readable - how?
I am retrieving data from some old optical discs.
I came accross a CD with physical hole about 1 mm in diameter in the data layer. The plastic carrier is fine.
The hole is actually in a place, where ...
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1
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Troubleshooting ST-238R and WD1002A controller card
Having a cryptic issue with this pair of hardware. Scenario:
Amstrad PC1640DD (manual here) with one floppy long since swapped out for an HDD. Exact controller card is WD1002A-27X (board photos ...
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2
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1
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How do I replace the CMOS battery in a P II Dell Inspiron 7000 A366LT laptop?
I have a 366MHz Dell Inspiron 7000 P II A366LT laptop which is in new old stock condition. I'd like to replace the CMOS battery.
What type of battery is required? (CR2032, sleeved/jumpered, etc?)
How ...
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Which aspects of RF emission were TI unable to get under control?
The TI 99/4 (as opposed to 4A) was a computer killed by RF emission problems. From Wikipedia
Through the development period, several companies attempting to enter the home computer market were faced ...
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Were there 3D accelerators built on discrete logic?
I wonder if there were 3D accelerators (that is, a device that calculates rotations, scaling, texturing, etc. for 3D points) built on discrete logic (7400 series, most likely its fastest variants, ...
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Is there a technical reason why Datel Action Replay on PC required a card?
In the mid-90s, there was an ISA expansion card called “Datel Action Replay” that could be inserted into almost any PC-compatible machine (e.g. 80286). By pressing a button on a device (plugged into ...
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What contemporary hardware was available for the development of Atari 2600 (or other 2nd gen) games?
The Atari 2600, along with others like the Odyssey 2 or Intellivision, were among the first programmable home game consoles. They existed alongside personal computers like the Apple II and Commodore ...
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What is this large device labelled 'Telefunken Datenspeicher' and how does it work?
We found this device in our school. Does anyone know what this can do exactly, and how it could work?
We managed to input values into the bit storage on the top, but nothing more. Can we calculate ...
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When did the PC bus start slowing access to video RAM?
The PC architecture, from the original IBM PC onward, has always been designed around the idea that video memory will be on an expansion card. This was an unusual design decision; most 80s computers ...
- 65.3k
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Why must the Amiga 1020 disk drive be powered-on before and powered-off after the Amiga computer?
The Amiga 1020 was a 5.25" disk drive for use with the Amiga computer. Anecdotally, I suspect they are somewhat rarer these days because they were a less popular choice for a second drive back in ...
- 11k
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Gameboy Key Input Causes Crash
I made a Key Tester using the STDIO header included with GBDK. It works... Until it doesn't. All the keys register and print to the screen, except the Left(5) and Right(4) Directional Keys, which ...
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Can the MC6850 ACIA signal that it wants to send data but not receive it?
I want use MC6850 ACIA for bidirectional communication, but I am not sure if I've understood it well.
I want use an IRQ to interrupt an MCU when the ACIA receives data or has transmitted it. The MCU ...
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Was there any computer since about 1960 without interrupt support?
The invention and spread of interrupts in the 1950s is reasonably well known but I am curious: were there any systems after which didn't support them?
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Troubleshooting Legacy Hardware and Software Issues on MS-DOS and Windows 3.11
I have an old PC with the following hardware components:
Motherboard: AMI TITAN II EISA rev.D
RAM: 48MB of 4 SIMM
CPU: 154C Pentium (tm)
BIOS: 711011596
HDD1: SCSI controller adapter through PCI (PCI)
...
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1
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Do Z80 datalines need termination [closed]
If I am using a z80 can you just tie all data lines to the ROM 28c16 or do they need termination via 10k ohm resistors to ground?
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Why is my crystal oscillator (4 pin DIP 4 MHz unbranded from ebay) producing unusable clock signal waves? [closed]
I was trying to make a Z80 computer (I tried with Intel 8088 and failed because I am dumb) so I bought a 4-pin 4 MHz crystal(from here:ebay listing) and I tried to check the crystal by connecting it ...
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TMS9918 - why have separate data-in and data-out?
Usually 8bit video chips interface with DRAM using:
an address bus for rows and columns,
a bidirectional data bus
in the case of 1bit DRAM data-in and data-out pins are shorted on the same data line....
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Can someone help me port the fat32 library used in the x16 to my homebrew 65c02? [closed]
A little background:
As a retired electronics technician, (not engineer), I decided to design and build a 65C02 based computer. Only after building it did I realize how important advanced or ...
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Was hardware scrolling patented?
One of the most valuable graphical features on early computers that had it, was hardware scrolling, that allowed the horizontal position of the screen to be adjusted by one or more pixels, thereby ...
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Why does the Commodore 64 have 4K of non-banked RAM at $C000?
I wonder why the Commodore 64 memory map was created as it was. Naively, it seems to be that it would have been more logical to put I/O and the character ROM at $B000 to $BFFF, have the ROMs in a ...
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Where can I find information on old Kontron emulators?
Way back in the mid-80s, I worked as a programmer for the Apple II family, Commodore and Atari machines. I remember programming them using a big intimidating box branded Kontron stacked on top of my ...
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Netronics Explorer 85 level A interrupt handling mechanism
I'm trying to understand how the RST 7.5 interrupt circuit works in the Explorer 85 level A, since in the i8085 the address jumped is located in 003CH (for level A there is no memory mapped here), but ...
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