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3 votes
0 answers
197 views

Is it possible to corrupt a Nintendo 64 save file by turning off the console when saving to the cartridge?

All consoles with memory cards (including Nintendo 64) kept reminding you that it's very important to not turn off the power while it's saving, because this would corrupt the save file. But for the ...
  • 31
5 votes
1 answer
728 views

MS DOS 6.22 hangs on modern hardware after loading HIMEM.SYS

I am trying to run MS-DOS 6.22 on modern hardware. I successfully created bootable flash disk with MS-DOS 6.22. But when it starts with HIMEM.SYS enabled in CONFIG.SYS it hangs. Searching Internet the ...
28 votes
2 answers
6k views

How could the SNES take advantage of in-cartridge coprocessors that weren't invented when the SNES came out?

The SNES had a number of "enhancement chips" that were available in the cartridges. These chips did lots of different things. How did these chips actually transfer data to the SNES? How did ...
13 votes
3 answers
3k views

Were Windows 3.x applications dependent upon 80286 instructions?

While Windows 3.x operating system stuck to the 80286 platform, did applications compiled for Windows 3.x have to use 80286 instructions explicitly or be aware of the 80286 memory layout? Or was it ...
  • 2,950
7 votes
3 answers
2k views

Dimension of a 3.5-inch floppy disk

Can anyone tell what are the dimensions and/or volume for a 3.5-inch floppy disk? I am doing a presentation and want to make a visual on how many floppy disks are required to save 200 GB (73662 floppy ...
5 votes
1 answer
236 views

Why can't the VIC-II handle ECM and Multicolor at once?

On the Commodore 64 there are a few different graphical mode selection bits we can enable. This question is about three of them: Multicolor mode (hereinafter MCM), where pixels are joined pairwise ...
9 votes
1 answer
1k views

Purpose of Recover command in MS-DOS

Continuing my reading of Dan Gookin's MS-DOS 6 pour les nuls (More DOS for Dummies ?), I've discovered in an otherwise light and funny (at least the French translation is) book about DOS a section ...
  • 1,203
12 votes
2 answers
650 views

Why does the FRE() function in CBM BASIC v2 return negative values?

On Commodore machines featuring CBM BASIC v2, the FRE() function to query the amount of memory available to BASIC returns a negative number when the result exceeds 32767 bytes: This quirk does not ...
  • 6,722
13 votes
2 answers
998 views

What was the first commercial route planning software for home computers?

Nowadays route planning applications are ubiquitous on smart phones, on embedded or dedicated devices, and on the web. With these applications, you input a destination and a starting point (or the ...
  • 6,722
7 votes
4 answers
3k views

Why would poking an inserted Game Boy cartridge while powered on cause a game/device to hang? [duplicate]

I say "a device" because I'm not convinced that this happens on an actual Game Boy. (I haven't been able to provoke it on mine yet.) I've seen several videos of people showing how their ...
  • 87
26 votes
5 answers
3k views

Why does the FAT file system have separate ‘hidden’ and ‘system’ attributes?

File systems used by DOS and Windows have used file attribute bits as a relatively prominent feature. The first of them, FAT, exposes four attributes to the user: read-only, archive, hidden and ...
  • 19.8k
6 votes
1 answer
470 views

How does POST memory test work on a relatively modern (2000s) PC? Does it still test every single byte like on older ones?

I have an Asus eee 4G (AMI BIOS), I want to ask if this product actually overwrites the entire RAM during cold boot. I have the "Quick boot" feature turned off and I can see the memory being ...
  • 61
5 votes
2 answers
178 views

Why did some BIOSes have the timer tick wrap around at 1800B1h instead of at 1800B0h?

The 1989 2nd edition of the DOS PROGRAMMER'S REFERENCE says: Midnight is determined as the number of ticks in a complete day of 86400 seconds (1573040 ticks of the clock, for a total elapsed time of ...
5 votes
0 answers
55 views

How can I replace the floppy drive mechanism in a A-1011/CD-1411

I have a Commodore CD-1411 external floppy drive which I connect to a CDTV. Unfortunately it is not reading any disks reliably anymore despite cleaning the heads. Inside I found a Chinon FB-354 rev D ...
14 votes
1 answer
876 views

What technical aspects make NEC PC-98 architecture incompatible with IBM PC architecture?

PC-98 was a series of x86-based Japanese computers that offers Kana-Kanji support, which shared some hardware similarities and operation systems with IBM PC, and software was relatively easy to port ...
  • 2,950
6 votes
1 answer
294 views

Best 4-color palette for dithering arbitrary images [closed]

While 8 or 16 colors can offer a relatively satisfying result of dithering, 4 color palette results varies. Below are some acceptable results. BBC micro mode 2 8 colors NES 4 color full screen CGA ...
  • 2,950
5 votes
0 answers
147 views

What percentage of the SID was control versus voices?

I'm interested in specifics of the design and manufacturing of the SID, the sound chip of the Commodore 64. There is a good die photo here http://www.visual6502.org/images/8580/...
  • 53.3k
10 votes
0 answers
183 views

What was IBM's internal Specification Language of the 1980s?

Within IBM's internal Development community, there was a move in the 1980s to bring our skills up to date. As part of this, we were introduced to a specification language, independent of the ...
  • 201
19 votes
1 answer
3k views

How did SmartDrive work?

I've recently unearthed an old book called MS-DOS 6 pour les nuls (More DOS for Dummies) by famed C programmer Dan Gookin. It was (still to me) a very interesting book in which he talks about MS-DOS ...
  • 1,203
34 votes
4 answers
8k views

What motivated stack being invented originally?

In the very early days (the earlier the better! Babbage maybe?) when something like a stack was developed, what motivated it originally? I am aware that these days it makes many features possible, ...
3 votes
1 answer
136 views

How can I check whether a define-style string macro is defined in CA65?

I have spent hours trying to figure out how to get conditional include paths functional in CA65 (or really, any conditional string values at all). Is it even possible? What I want is to be able to ...
37 votes
9 answers
12k views

Why was USB 1.0 incredibly slow even for its time?

USB 1.0 is from 1996 and has a transfer rate of up to 12 Mbps. I think it's extremely slow even for its time. Because here are two similar standards from the same time which are much faster: IEEE 802....
  • 3,029
4 votes
1 answer
122 views

What year was the CD4041 / HEF4041 introduced?

Most of the 4000 series CMOS logic was available and fairly established in the mid-70s. I’ve had some trouble figuring out when the CD4041 quad positive/complement driver was introduced - and by which ...
16 votes
4 answers
4k views

Was the ZX Spectrum used for serious number crunching?

From Eurogamer’s obituary of Sir Clive Sinclair: Sinclair never intended for his computers to be games machines, but that was what the market decided they were. Within the space of a few years, the ...
-5 votes
2 answers
244 views

What are common instructions used to put the CPU into idle mode in the past? [closed]

I once did some tutorials on osdev.org and one interesting point was how the CPU is set into idle mode. Because when no task has work to do you want to put the CPU into idle mode and not consume any ...
  • 3,029
8 votes
1 answer
313 views

What versions of MS-DOS or PC-DOS supported the "+,," syntax on COPY? Is there documentation on its origin?

I remember reading in an IBM PC-DOS manual, around 1988 maybe, that there was a special syntax of the COPY command : COPY A.TXT +,, which would simply update the file's last change date to now. This ...
  • 2,018
2 votes
0 answers
122 views

Where can I find a list of official Windows ME updates (security patches, etc.) that came after the RTM version?

I am using the Windows ME final version (4.90.3000, German; newer installation CDs are not available). I am looking for a chronological list of updates that came after this version, that in the past ...
  • 3,029
3 votes
1 answer
138 views

Why memory read (M2) cycle in Z80 is three T cycles and not two?

In Z80 memory read cycle is three T cycles, but, 2nd cycle only does "WAIT", and it appears timing would work with just two cycles unless the "WAIT" does something important. What ...
3 votes
1 answer
312 views

Is RosAsm assembler self-hosting?

I have a few questions about the RosAsm assembler (not in active development anymore) by René Tournois: Is/was there a command-line tool (i.e. without a GUI) included to generate executable programs ...
  • 1,295
14 votes
4 answers
1k views

Looking for an open source DOS .com program written in assembly

I'm writing a NASM-compatible assembler targeting the Intel 8086, and I'm looking for an existing open source program written in assembly, with which I can showcase the capabilities (and understand ...
  • 1,295
6 votes
5 answers
390 views

Would compare-and-branch have added an extra cycle on ARM-1?

The ARM-1 was an early RISC CPU, designed in 1986 (and even more typical of early RISC design constraints than the year would suggest, since Acorn didn't have the budget to pay for the latest process ...
  • 53.3k
15 votes
4 answers
5k views

What was the last x86 processor that didn't have a microcode layer?

In the earlier days of microprocessors instructions were hard-wired, i.e. a particular instruction triggered circuitry that was mostly (if not completely) implemented for that instruction. I believe ...
  • 15k
36 votes
8 answers
7k views

Did they forget to add the physical layout to the USB keyboard standard?

USB keyboards must have been one of the first devices that could be connected to a USB port. When you are from the US it's possible that you have never faced this problem. But in all other parts of ...
  • 3,029
23 votes
6 answers
6k views

Were CD-ROM-based games able to "hide" audio tracks inside the "data track"?

I have been digitizing the audio tracks from various old CDs lately, because I have become a lossless audio snob who no longer is able to tolerate MP3s but need FLACs of everything. Many of these are ...
  • 231
6 votes
1 answer
496 views

Why did old CD ROM drives spin super fast if they couldn't read the disk?

This is a memory I have of just about every computer with a CD ROM drive in the mid 1990s to early 2000s. If you put in a disk that, for whatever reason, the drive couldn't read, it would spin like it ...
15 votes
2 answers
9k views

Why did Microsoft start Windows NT at all?

A related question is: why was the existing Windows not ported to the Intel i860? In 1985 Windows 1.0 was released. AFAIK it had everything: Win32 API, DOS support, multi-tasking. The last OS of this ...
  • 3,029
2 votes
0 answers
92 views

Toshiba Libretto 50ct replacement display

Is there a cost effective new display panel that could fit to retro Toshiba Libretto 50ct? Mine is broken and panels are hard to find. Maybe little bigger like in Libretto 70ct could fit too with new ...
25 votes
8 answers
7k views

Why did x86 support self-modifying code in the 80s and 90s?

In this question, by 'self-modifying code', I mean software that writes to a section of code that the CPU will very soon fetch and attempt to execute. I am not here talking about the software ...
  • 53.3k
9 votes
1 answer
399 views

Are the 16 linear steps of the SID Sustain and Filter Volume/Resonance steps of 6.25 or 6.666666667?

The SID has various registers that are described as 16 linear steps: The Filter Volume, The Filter Resonance, and the Sustain of the voice envelopes. The SUSTAIN levels range from zero to peak ...
  • 930
6 votes
1 answer
244 views

SUSE package system before adopting RPM

RPM, or RedHat Package Manager, was developed by RedHat for their flavors of Linux, though it is now used also in SUSE flavors. What was the package system in SUSE predating the adoption of RPM, and ...
11 votes
1 answer
952 views

What was the purpose of the ‘overlay number’ field in the MZ executable format?

Many materials covering the layout of MZ executables (RBIL, for example, and even a comment in MS-DOS 2.0 source code) describe the word at offset +0x1a as the ‘overlay number’, with the value zero ...
  • 19.8k
8 votes
3 answers
2k views

Why was the size of the 1989 Intel i860 (aka 80860) memory bus 64bit?

On Wikipedia I have read the i860 from 1989 memory bus was at least 64bits wide. (It is the first CPU the Windows NT kernel was running on.) I think even 10 years later (1999) most desktop CPUs were ...
  • 3,029
9 votes
1 answer
440 views

How can I properly execute and clean up after a DOS MZ executable loaded into memory with int21 function 4b01h?

Ralf Brown's Interrupt List describes a subvariant of the DOS int21/4Bh function with AL=01, where the program is loaded into memory and a PSP + stack are allocated for it, but the program is not ...
13 votes
1 answer
1k views

Using a Minitel keyboard with a modern PC

I have a problem for my next project. I want to buy a Minitel (a French terminal, ancestor of PC and Internet). Once I have it, I want to remove the old screen and everything that is inside then put a ...
12 votes
3 answers
6k views

Does the kernel of Windows 95/98/ME have a name?

In this question: Why was the DOS kernel discarded? I was told that DOS is not a kernel. It runs on CPUs that don't even have kernel mode. So how can it be a kernel? So I think this is right. Now if ...
  • 3,029
6 votes
2 answers
2k views

Why do most of my games have graphics errors on my Windows ME retro PC?

I've built a retro PC with Windows ME, a GeForce 2 MX 400 (drivers installed) and DirectX 8.1. But it seems many of the games have graphics errors. In most cases these are black areas. (See ...
  • 3,029
16 votes
1 answer
2k views

Was any DRAM ever slower than 2 MHz?

4096-bit dynamic RAM chips were commonly used for main memory in microcomputers of the late seventies. According to the Mostek MK4096 datasheet, it was sold in various speed grades, with the slowest ...
  • 53.3k
21 votes
8 answers
6k views

Why were nested functions excluded from B and C?

I'm learning C and was curious as to why the language does not allow nested functions. From what I've read, the lack of nested functions seems to have been a simplification that was inherited from its ...
  • 311
8 votes
2 answers
1k views

Apple IIe SYNTAX ERROR

I inherited an old Apple IIe computer. I have a dual disk drive and connected to a modern TV screen as the original monitor was fried. On turning on the computer, nothing happens except "Apple ][&...
2 votes
1 answer
175 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. ...
  • 3,029

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