Questions tagged [hardware]
Retro hardware generally: boards, extension cards, power supplies, peripherals. Use more specific tags as appropriate; use [case] instead for enclosures.
552
questions
5
votes
0
answers
191
views
Where can I find a schematic of the AT&T KBD 301?
Where can I find a schematic of the AT&T KBD 301?
I have an old AT&T 6300 (AT&T's rebrand of the Olivetti M24) but the keyboard (AT&T KBD 301) is not working.
Many of the keys do work ...
- 399
18
votes
10
answers
8k
views
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?
- 773
3
votes
0
answers
306
views
Two Unknown Sony Corp Boards - Please identify
There are two Boards:
The first one has
Chips with the name "Sony 501 0C 185", "Sony 502 0J 043", "Sony 504 1B 002 504-3", "Sony 509 01 017 509-00", "Sony ...
3
votes
0
answers
154
views
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)
...
- 31
1
vote
0
answers
136
views
Defective Apple IIe motherboard
I have a PAL Apple IIe, put in service in 1982. Components C9, C12, C15, and C17 on the 820-0073-B motherboard are burnt out. I originally thought they appear to be power diodes, but seem to be 10 µF ...
- 11
3
votes
1
answer
182
views
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?
- 31
4
votes
1
answer
119
views
Mac Plus refusing to read disks
OK, so I was gifted a Mac Plus a couple weeks ago, and finally got it up and running a couple days ago (had to wait for mouse and a couple lots of disks for it to arrive, since it came as just the Mac ...
- 143
1
vote
0
answers
213
views
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 ...
5
votes
1
answer
1k
views
What sort of LCDs are used by the Game Boy/TI-83 calculator/etc.?
The Wikipedia article on the Game Boy lists the display as an STN display, whereas the ones for TI graphing calculators don't give any detail. However, even knowing that it's an STN display only ...
- 455
11
votes
3
answers
804
views
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....
- 1,239
12
votes
2
answers
1k
views
What are the electrical properties of the EAR and MIC sockets on a ZX Spectrum, and can they be connected between machines?
I'm interested in the possibility of connecting two ZX Spectrum computers together using as simple an interface as possible.
The ZX Spectrum has two mono audio sockets at the back labelled EAR and MIC....
- 11.8k
4
votes
1
answer
278
views
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 ...
- 101
14
votes
1
answer
2k
views
How did Altair 8800 interrupts work?
I'm playing around with building an Altair 8800 emulator in my free time in C#. I've read through the Operator's Manual many times in the past, and I'm refreshing my memory of late.
I'm struggling to ...
- 243
1
vote
0
answers
287
views
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 ...
- 58.4k
5
votes
1
answer
384
views
Why does the VIC-20 have its cartridge area at a higher adress than the I/O area?
Why did the designers of the Commodore VIC-20 chose to put the main cartridge ROM area at $A000, beyond the character ROM area at $8000 and the I/O area at $9000? Flipping the two around, with the ROM ...
- 703
25
votes
1
answer
3k
views
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 ...
- 703
18
votes
5
answers
3k
views
What is the most accurate way to map 6-bit VGA palette to 8-bit?
AFAIK VGA mode 13h palette has only 64 possible colors (6-bit) per channel.
One obvious way to map those 64 colors to 256 colors is to multiply them by 4 (since 4 * 64 = 256):
8_bit = 6_bit * 4;
This ...
- 283
6
votes
0
answers
203
views
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 ...
- 382
9
votes
2
answers
2k
views
Why did the Apple III have more heating problems than the Altair?
The Apple III was famously prone to overheating, to the extent that Apple advised customers to drop the machine a few inches onto the desk in the hope that this would knock chips back into their ...
- 58.4k
0
votes
1
answer
112
views
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 ...
- 153
16
votes
4
answers
3k
views
Did anybody use PCBs as macro-scale mask-ROMS?
Early on, even fairly small ROM's were quite useful. For example, you could fit a minimal upper-case only font for a terminal into something like 256 bytes. And that's a scale that a human could lay ...
- 2,264
4
votes
0
answers
359
views
Snack shipped with computer products [closed]
I remember that there was a company in the US that packed candy or snacks as a bonus in the shipping box with their products. They were well-known for this practice. I'm pretty sure the snack was ...
1
vote
1
answer
183
views
Why does my Mikrolab randomly freeze and unfreeze, and what can I do about it?
I've started using my Soviet Mikrolab KR580IK80 (a clone of the Hewlett Packard 5036A) again, and I've noticed some behaviour which it used to exhibit but now it seems more frequent. Basically after ...
- 2,903
7
votes
3
answers
1k
views
Sending video to Telerate 9" Green Monitor [closed]
I found an old Telerate green monitor at a thrift store and figured I could run my computer output through an HDMI -> AV converter with no problem, or a Raspberry Pi composite output signal. Turns ...
- 81
3
votes
2
answers
342
views
When did CMOS processors become the fastest?
The earliest CMOS microprocessors (RCA 1802, HP Stirling RISC, et.al.) were slower than contemporaneous NMOS microprocessors and Bipolar logic computers. (IIRC, both the 1802 and the 6502 could be ...
- 8,125
0
votes
1
answer
303
views
I have old hardware; what can I use it for? [closed]
I have two old pieces of hardware: a DVD drive and a hard disk, both from 2004, which I would like to use.
I have a computer made for Windows 7, currently running Windows 98 which would probably run ...
10
votes
1
answer
335
views
How did relay computers handle inductor flyback?
Many early computers were relay-computers. Like any other inductor, when the coil in a relay is shut off, the current through the coil continues to flow. This is a result of Faraday's Law of ...
- 15.8k
3
votes
1
answer
637
views
How can I repair a sketchy video signal on a 1977 Pong unit?
I bought a 1977 Gracia Color Video Game TVG 432 (not much to be found online), image from 20th Century Video Games:
And the unit works, but the video signal is kind of sketchy.
It is not very strong, ...
- 851
18
votes
3
answers
2k
views
Why was the VIC-II restricted to a hard-coded palette?
The MOS VIC in the VIC-20 and the MOS VIC-II in the C64 were capable of outputting 16 colours drawn from a hard-coded palette.
It's clear that the palette size was fixed at 16 colours as a memory-...
- 7,023
3
votes
0
answers
247
views
VisiCalc V1.0 is not working on modern computer as expected
I am trying to run Visicalc on the modern laptop (Lenovo Thinkpad X1 Extreme Gen.2). I created bootable flash drives with DOS 6.22 and Free DOS, booted from them and ran visicalc (vc.com file).
All ...
- 183
16
votes
2
answers
2k
views
What was the last terminal to include a physical bell?
Drew asks:
… what was the latest terminal produced which rang a physical bell rather than beeping through a speaker?
- 20.5k
6
votes
1
answer
597
views
Maximum current a GBA Game Pak can continuously draw
The GBA (specifically model AGB-001) uses a boost converter to power the Game Pak with a stable 3.3V from its batteries. The SP and Micro models use a buck-boost regulator to generate that same 3.3V. ...
- 1,999
2
votes
1
answer
195
views
Is it possible to view hardware-reported device identifiers on Windows ME?
On Windows XP and later you can view OS device identifiers for a given hardware component in Device Manager; those often include hardware-reported device identifiers, like PCI vendor/product ID pairs.
...
- 4,670
7
votes
1
answer
2k
views
Is there something like Retr0bright but already made and trustworthy? [closed]
I have long wanted to clean up some old hardware to make it look new again. It really bothers me that it's all yellowed and depressing-looking.
However, https://retr0bright.com/ wants me to purchase ...
- 81
3
votes
4
answers
2k
views
What did game programmers and journalists mean by a "hardware trick"? [closed]
Recently, I've been hearing a good deal about hardware tricks. For instance, the YouTuber Ahoy (see A Brief History of Graphics) mentions that some game programmers resorted to "hardware tricks&...
- 55
5
votes
1
answer
580
views
How did the Windows 95 'Add New Hardware Wizard' work?
I remember when Windows 95 came out and the 'Add New Hardware Wizard' seemed almost magical! It was able to detect a large amount of hardware on the COM ports and automatically install drivers. It was ...
- 153
10
votes
5
answers
3k
views
Why does MOS 6502 require an external clock if it has an internal oscillator?
I have a trouble understanding how the MOS 6502 clock works. Possibly due to my extremely low knowledge regarding electronics in general.
According to the Wikipedia:
MOS would introduce two ...
- 201
6
votes
4
answers
1k
views
Fire button of Timex TC/TS 2068 Joystick
These pages wos and timex.comboios.info suggest the fire button of the Timex TC/TS 2068 joystick is read at bit 4.
Input:
bit D0: up (0=active)
bit D1: down
bit D2: left
bit D3: ...
- 2,590
7
votes
2
answers
319
views
Was there ever a monospace display system (eg terminal) that used a vertical cursor?
Related to my earlier question about IBM PC cursors, I am now wondering if there has ever been a monospaced character display system (such as a terminal) that would've implemented a vertical cursor in ...
- 2,753
2
votes
1
answer
180
views
HP Photosmart 620 stuck formatting SD memory card
I am trying to resurrect a 20-year-old digital camera, an HP Photosmart 620. The plan is to turn it into a third grader’s first camera.
It powers on just fine and can take photos using its limited ...
- 121
3
votes
1
answer
576
views
Windows NT drive recovery without ERD or backups
I have decided to take on this project to help another company that has been using a Windows NT system to run some of their critical field equipment.
Unfortunately there is now an error which appears ...
13
votes
1
answer
422
views
Was there a hard disk type that had a SMART overflow crash/bug?
A data center employee told me a story about 25 years ago, explaining why that data center took some time to assemble a RAID array. Recently, I wasn't able to verify the facts by googling, and I may ...
- 273
11
votes
2
answers
863
views
Information about the Hollywood Hardware Graphics Card for Apple II+
I still have a Hollywood Hardware graphics card that I used in my Apple II+ back-in-the-day. It was my understanding that this was the graphics card used for the special effects in the first three ...
- 111
6
votes
2
answers
605
views
What would it take for a 6502 system to use an 8 bit ISA bus
I've built 6502 computer on an ISA card:
To access the bus it decodes the following 6502address ranges
$0200-$03FF mapped at I/O address $00200-003ff (IOR; IOW)
$4000-$BFFF mapped at ISA address $...
- 101
1
vote
4
answers
309
views
I found an apple IIe without a power supply where can i find one [closed]
I found an apple IIe without a power supply where can i find one also any tips on where i can find other parts for it. Btw i know nothing about Retrocomputers.
- 11
21
votes
4
answers
3k
views
What is the history and development of memory caching?
I have tried to research the history and development of memory caching online, but I find it hard to find good information. Many resources online would have you believe caching was introduced with ...
- 3,101
1
vote
1
answer
517
views
Why audio of Prince of Persia (1989) produce in CPU rather than audio speaker? [closed]
I used to play this Prince of Persia (1989) in Pentinum III computer.
But audio of Prince of Persia (1989) produce in CPU rather than audio speakers.
Why?
- 13
-4
votes
1
answer
430
views
If I build a new CPU architecture, how would an OS like Linux know how to run it? [closed]
I am trying to build a CPU from scratch (from NOR gates) in an emulator first, then on breadboard. (Inspired by nand2tetris and Ben Eater)
Just trying to understand how things work.
Now, as my CPU ...
15
votes
2
answers
2k
views
Were there any enhancement chips that vastly outperformed the main CPU?
Were there any enhancement chips in officially-released games that were CPUs themselves and which ran the game code itself, relegating the role of the main CPU to that of a thin client?
To elaborate, ...
- 1,999
4
votes
2
answers
555
views
Why do computer rooms no longer have raised floors? [closed]
As I understand it, computer rooms in the days of mainframes and minicomputers, commonly had raised floors, so that the space under the floor could be used for power cables and cool air.
I'm not clear ...
- 58.4k