All Questions

My friend told me that earlier iterations of the Pentium 4 were not as fast as the Pentium III, but he didn't have sources. Is it true that the Pentium III was faster than its successor Pentium 4?

I just picked up a used Apple IIc. For some reason all I get when I boot is Check Disk Drive on the screen, even with a bootable disk in the internal drive: I cannot even get the system to read the ...

I purchased a vintage Apple IIc computer and I want to make sure there are no failing components. I booted up the computer while pressing both Apple keys (open and close) at the same time. The ...

Back in the 1980s-90s, using a UNIX system required running expensive servers or paying for timesharing service, so they were beyond the reach of most individuals, and only available to members in ...

The 80486 processor can execute many instructions in a single cycle, such as a register-to-register add instruction (ADD EAX, EBX, for example), which one would generally assume is fairly complex, ...

If I upgraded, say, a Macintosh II with larger SIMMs, naturally the machine detected that additional RAM. But how did it perform that check? Does it simply sweep all addresses until it fails? Or ...

When Nintendo used the 6502 core in the NES (as part of the Ricoh 2A03/2A07 microprocessor and sound generator), they circumvented the 6502's patent protection by disabling the BCD arithmetic. As a ...

In his June 1985 foreword to Programming the 65816 by David Eyes and Ron Lichty, Bill Mensch expresses his hopes for a 6502-derived 32-bit microprocessor: the 65832. WDC is still thriving, but the ‘...

I have recently been learning to use vasm. For those that don't know, vasm is a cross-platform assembler for multiple types of processors such as the M68000. http://sun.hasenbraten.de/vasm/ I am ...

After working on some tools that parse the TR-DOS disk image format .TRD files for a while I just noticed that one of the game disk images I had downloaded "La Abadia Del Crimen", only has three files ...

I find I keep on doing things like this: raster_interrupt: bgnd_color = * + 1 lda #$00 sta $d021 ; rest of interrupt handler so that I can do this kind of thing elsewhere in my ...

I've been working on some modules for the Ghidra reverse engineering tool. Ghidra is written in Java, which I'd always avoided when I was more actively programming so this is an opportunity to learn ...

I am using a USB connected "Sabrent FD-05PUB" 3.5" floppy drive to read data using Windows 10 computer. It shows in Device Manager as "TEAC USB UF000x USB Device" The 1.44MB disks read just fine. All ...

While considering the recent question on Integer BASIC, a thought arises: Most systems using/supporting integer math used a 16-bit signed format. In the case of Integer BASIC, this leads to odd-...

A real-time text editor is a program which facilitates editing text. In the process, the text is displayed on a screen, and the displayed text is updated after each key press. A commonly cited ...

Does anybody know the meaning of this message from the Apple IIe diagnostic? IOU FLAG E5: 1 2 3 4 8 What are addressing the 1 2 3 4 8? I’m pretty sure that IOU is the I/O chip, E5 is the location ...

How picky are CRTs about the 'cleanliness' of the mains power? Cleanliness referring to electrical noise from thing like ac motors in fridges, powerline ethernet, etc. Cleanliness is also referring ...

I was watching a video on a Soviet submarine armed with the P6 cruise missile: https://youtu.be/9LiZGdXBw3I?t=156 The video mentions "It could use the lead missile in the group to find targets and ...

The Z80 is "binary compatible" with the 8080. It adds a bunch of new instructions, but places them all in unused (well, undocumented) opcodes. Does this mean that if I disassemble an 8080 program (...

I'm trying to add a compact #define macro in a cc65 program for performing various low-level tasks efficiently. For some of the macros, I need to pass a non-constant value to the assembler part. I ...

If you've used legacy Windows, you probably know about program information files aka PIF files. At some point, when Internet usage became widespread, these files became a vector of infection for ...

I was just writing some junk Speccy Basic programs, more to see how they take up space on the +3's disk layout than to do any actual programming. But I noticed that after editing a program line to ...

A friend is trying find the original brand and model of this old 1990’s generic case. An ad from computershopper would help.

Using my 21" Trinitron OSD, I can see that the resolution at boot is 720x400. From memory, this weird resolution is extremely uncommon if ever to be seen as a choice on software that supports ...

Back in the day, I had a Windows 98 machine (don't recall the hardware right now) and sometimes it would crash with the "Windows protection error. You need to restart your computer" error. So, what ...

The 6502 series of CPUs has an interesting quirk: indexed loads and stores may perform a "false read", reading from the target address or a different address on a previous page. There are situations, ...

What prevented optical drives from being used as the dominant secondary storage like the magnetic disk drives, in PCs? Was it entirely technical limitation or other issues like late development and ...

What are the dimensions of the C64 motherboard? I am specifically asking this because I am considering using a 64C case (these still seem to be in production) for an 8-bit homebrew machine. I wonder ...

In this image, you can see, from the right, a 16-bit ISA slot (occupied by a controller card), an 8-bit ISA slot, four more 16-bit ISA slots, and two of these strange slots that look like a 16-bit ISA ...

What's the name of this output retro gaming monitor device? The following is a still from the Netflix production of 'Bandersnatch', a 2018 interactive movie, set in Britain, mostly in the year 1984. ...

From Wikipedia's code page article: Originally, the code page numbers referred to the page numbers in the IBM standard character set manual Is any version of this publication available? I'd be ...

Originally, the FTP protocol connected back from the server to a client to actually transfer files through that new connections. 14 years later after the introduction of the FTP, the 'passive mode' ...

From what I understand of this answer, the Leningrad delays the Z80 during the M1 cycle so that the video generation circuitry can do its thing. I can see how M1 is "latched" (don't know if that's ...

While researching the underpinnings of Integer BASIC (IB), I came across an oddity I'm hoping someone can explain. Unlike MS-derived systems, IB converted numeric constants to their 16-bit ...

The Spectrum+3 uses a version of the Amstrad and CP/M disk layout. The Speccy version has a directory at the start of the disk after any reserved tracks and it can hold up to 64 files. Each ...

I recall a confirmation/warning message that read something like "this will post to thousands of sites... are you sure?" What was a typical such message in the days of pay-per-minute dialup access?

Inspired by Ben Eater's "Let's build a video card" aka "World's worst video card" two part projects on YouTube, I was inspired to consider designing a display adapter for my passive backplane TTL mini-...

A 1980 paper called "Register Allocation via Coloring" contains something that looks like source code: P: PROC(MODE); DCL MODE BIT(1), (A1,A2,A3,A4,A5,A6,A7,A8,A9,A10, B1,B2,B3,...

What techniques were used for implementing breakpoints on the ZX81? Traditionally for the 8086 int 3h is used, for the 8080 on CP/M with DDT RST 7 as single byte replacements, 6502 has the BRK ...

While searching on the Internet and Quora, I found disassemblers for Pac-Man, Galaxian, and Super Mario Bros. The thing that puzzled me, was while Super Mario Bros was arguably quite a complex game ...

NOTE: I'm not looking for a way to transfer files from Linux to DOS over Serial cable Is there any MS-DOS driver to enable a new hard-disk drive (let's say D:), using a disk image on another ...

The first electricity-based adder presumably used relays. (The electromechanical relay was invented for the electrochemical telegraph for repeaters in 1831 by Joseph Henry (1797-1878). I can't figure ...

I am into playing with TTL to build 1970s style minicomputers. Aside from talking to them via some serial (or parallel) I/O port to a terminal, I am wondering about display output. This here is about ...

I have a subroutine with a for/next loop in Extended Color BASIC on the TRS-80 Color Computer that I would like, sometimes, to return early from. That is, to return from the subroutine from within the ...

The Welsh computer has a coax output and a resolution of 256x192, can I expect this to display at all on my Philips 50" 4K TV using the same input?

The Leningrad contains a shift register1, which I believe is loaded with data from the bitmap. This part loads 8 bits in parallel, and shifts each bit out in turn on the rising edge of a clock signal. ...

Windows 9x is no longer common, and isn't commonly supported. While there exist many solutions to burning ISO to USB or other storage device, most fail at some point, with commonly useless if any ...

Prior to 1972, was there any automated unit-testing? Did any assemblers include a testing a framework? I can find some academic journals on this topic from the late 70s -- most of which I don't have ...

I have been working on an old Siemens PG675 and suddenly the monitor began to show a a distorted image (it shows this 1 when the should shows this 2). I could make a test of the screen, and it shows ...

This question is related to this one. I always was understanding that windows the OS was a companion app of sort in regards to the server offerings and that, yes you could use it for home use, but it'...