All Questions

-3
votes
1answer
172 views

What does ld a,(hl) do in this piece of Z80 ASM code, and why is HL incremented?

ThinkPositive equ 1 PrintChar equ &BB5A org &8100 ld hl,Introduction call PrintString call NewLine ld hl,Message call PrintString ret PrintString: ld a,(hl) cp ...
4
votes
4answers
298 views

How can I implement the modulus operator in Commodore 64 Basic?

How can I implement the modulus operator in Commodore 64 Basic? There are not a lot of math functions to work with, and modulus would be very handy.
4
votes
1answer
241 views

Did the 286 go out of its way to follow the 8088 bus protocol?

In general, different CPUs don't use the same bus protocol. A 16-bit CPU would not in general be expected to use the same protocol as an 8-bit CPU. For example, the 68000 would not be expected to use ...
3
votes
0answers
102 views

Vic-20 total game cartridge sales

The Vic-20, like many home computers of its time, had a cartridge slot that could be used both as a general expansion slot, and for game cartridges like a console. Game cartridges on the Commodore ...
3
votes
0answers
117 views

How did the template cache in CFront work?

I've seen some discussion of how templates were historically implemented in CFront around the web, including here. The link describes the Borland model, which is familiar, and the CFront model with a ...
15
votes
7answers
4k views

Was the picture area of a CRT a parallelogram (instead of a true rectangle)?

This may seem like an absurd question at first, but I've been giving it some thought and I'm genuinely curious about the design details of these devices. I was reading an answer on an unrelated Stack ...
5
votes
1answer
302 views

DOS networking (Ethernet)

Would like to use a Linksys "Etherfast PCMPC100" PCMCIA network card under DOS 5.0, for file transfer. Am planning to use the "XFS" package to share directories with Linux. Have found an archive file ...
0
votes
1answer
146 views

Expanded Ram Options for the TRS-80 Model 100 possible into the megabyte range?

I have a trs-80 model 100. I have all the option rams used. I've seen some quite useful ideas from other collectors on the internet for other TRS-80 model computers of using mouser electronic parts to ...
4
votes
1answer
210 views

What was the “biggest” or the “greatest” task ever performed by MITS Altair 8800? [closed]

We know that computer is used for many things, to control many things, to do many jobs, as server, to control airplane traffic, and many things a computer can do. But I am curious about the MITS ...
3
votes
0answers
125 views

Identify this 1990s-era educational game featuring kohlrabi

I have fond memories of several educational computer games from school circa 1993–1998. Possibly from MECC, but I haven't found this game on any lists of MECC games as far as I could tell. It's a ...
3
votes
2answers
295 views

Was sneakernet a job description?

'Sneakernet' is a colloquial term for moving data by walking back and forth with a removable digital medium such as a floppy disk or tape in your hand. In 'IBM's 360 and Early 370 Systems', page 533, ...
3
votes
0answers
144 views

Preservation of old Computer Shopper magazines?

I am sure many of you remember the gigantic Computer Shopper magazines of the 1990's; but Computer Shopper actually dates back to sometime in 1979, and still exists in electronic form today. In my ...
0
votes
1answer
109 views

Where can I find and download emulator of Altair 8800 with Intel 8080 processor for Windows?

I would like to look back to the very beginning of personal computer when Paul Allen and Bill Gates started their debut. So I need to find an emulator of the MIT Altair 8800 with Intel 8080 processor ...
0
votes
1answer
172 views

What was the first keyboard to have browser forward/back keys?

I know they have been around for a long time, for example this 2003 commit has support for them. What was the first...?
20
votes
3answers
4k views

Did arcade monitors have same pixel aspect ratio as TV sets?

It is well known that when emulating classic games on modern displays, you need to be careful not to distort the aspect ratio. Generally speaking, CRT screens were 4:3, and specific pixel aspect ...
4
votes
3answers
365 views

Z80 unexpected output

I am trying to build a Z80 computer inspired by Grant Searle's design. I'm starting simple, with just a clock (clocked by an AVR pulsing at at 12.5 Hz for testing), a Z80, and a 8K EEPROM with a ...
4
votes
0answers
122 views

What would happen if the DHR jumper was enabled on a Rev A Apple //e?

The Apple //e originally did not support Double HiRes graphics (DHR). The engineers realized they could double their hires and lores X resolution shortly after the introduction of the machine, so the ...
-1
votes
2answers
207 views

Why can't BIOS be accessed in 64bit mode on Intel/AMD chips? [closed]

I was interested in a possible rewrite of dos to dos 64bit. In my research I found several references that state all current motherboard BIOS interrupts are not accessible from 64bit Long or 64bit ...
0
votes
3answers
223 views

How were early computer monitor signals used to breach security? [duplicate]

In the mid 80's, several national news outlets showed people able to reproduce a computer's monitor's screen at least 100ft away. 1) How were early computers compromised like this? 2) Were there ...
3
votes
3answers
203 views

Gotek drives for MS-DOS (plus few more constraints)

I have installed two gotek device instead of two old unworking floppy disk drives (in particular on an Olivetti PCS 86). And the result is something like this: (The one on the right should the the A:...
22
votes
3answers
2k views

How do I Interface a PS/2 Keyboard without Modern Techniques?

I'm attempting to build a Z80 homebrew computer to teach myself the basis of electronic design. I planned to start from something simple, like a ROM, some SRAM, a video chip and a Z80-PIO. I'd like to ...
3
votes
0answers
69 views

Documentation for the MIT PDP-1X OS

The PDP-1x is a Digital Equipment Corporation PDP-1 computer modified to support both ones and twos complement arithmetic, and to include a memory management unit. It ran a locally developed ...
10
votes
1answer
2k views

Did Nintendo change its mind about 68000 SNES?

Compared to its main rival from Sega, the Super Nintendo has a weaker CPU but a more powerful graphics chip. According to http://web.archive.org/web/20080505070423/http://www.eidolons-inn.net/tiki-...
3
votes
1answer
198 views

(Modern?) Examples of Creative Computing/Ahl benchmark being used?

I've recently written a Wiki article on the Creative Computing benchmark. I was wondering if anyone has examples of it being used outside Creative Computing? I've found one example in Compute!, but I'...
17
votes
3answers
4k views

When did hardware antialiasing start being available?

An important step towards 3D gaming was the ability to scale sprites or tiles by nonintegral factors. Examples of the former from the eighties were the arcade games Pole Position, Outrun, Space ...
6
votes
0answers
160 views

qemu emulating MS-DOS cannot access CD-ROM

I am using qemu-system-i386 on a Windows 10 PC to emulate an MS-DOS system. I have installed MS-DOS 6.22 successfully from disk images from original Microsoft media. I am starting qemu using this ...
2
votes
1answer
220 views

SNES PPU die photo

The heart of many classic home computers and game consoles was the graphics chip, yet these tend to be less well-documented than the corresponding CPUs. Still, there are die photos of two of the most ...
1
vote
0answers
92 views

Apple IIGS: Is there a way to boot and run an Apple II OS in E0/E1 in native CPU mode?

Apple //GS: Is there a way to boot and run an Apple ][ OS in E0/E1 in native CPU mode? No GS features are required. 1MHz clock like on previous Apple2s is perfect. The reason for needing this is ...
2
votes
1answer
218 views

Test emulated 8080 CPU without an OS?

I've found a few 8080 CPU test suites available, but they all assume CP/M or a similar OS is already present and running - they call BDOS for I/O, etc. I'm working towards being able to run CP/M on my ...
10
votes
3answers
1k views

Did CP/M support custom hardware using device drivers?

MS DOS Ver 1.0 did not have OS support for device drivers. DOS ver2 added support for device drivers in the config.sys file during boot with the "DEVICE=[path][filename][parameters]". Did CP/M have ...
2
votes
1answer
122 views

How to transfer file from one disk to another in Apple //e (Applewin)

For the nostalgia, I'm going through Apple Pascal - A Hands-on Approach using AppleWin. There are four disks, pascal0 through pascal3, and for some reason pascal0 is missing a file called SYSTEM....
28
votes
6answers
6k views

Latest web browser compatible with Windows 95 / 98

Do you know which is the latest web browser compatible with Windows 95 / 98? At the moment I have an Opera 10 working fine; it is very lightweight but very outdated. I assume that software that works ...
2
votes
0answers
104 views

How to reset/recover password on Ascend/Lucent “SuperPipe 155” ISDN router

I am trying to set up a second-hand 1990s era Ascend/Lucent "SuperPipe 155" ISDN router for use with some of my 90s era computers, but I don't know the router's password and the instructions I found ...
5
votes
0answers
216 views

What is the timeline of NASA ground control computers?

In the movie "Hidden Figures", NASA receives an IBM 7090 in 1961. What is the subsequent timeline of the primary computing means for flight planning and orbit calculation? Specifically, what was the ...
0
votes
2answers
308 views

Why did Steve Jobs say that Darwin is a kernel? [closed]

In this video, Steve Jobs introduces Mac OS X (in the year 2000), this is a snapshot from the video: He says that Darwin is the kernel for Mac OS X. Now the following is a diagram of the Mac OS X ...
1
vote
1answer
171 views

Which developer set the precedent for use of the Shift key for safety (or skipping) at startup time?

Which developer set the precedent? I began wondering after recalling that Mozilla Firefox starts in safe mode if Shift is held at application startup time. Predecessors … I'm certain that Netscape ...
6
votes
1answer
277 views

What commercial computers were based on the MC88100 and MC88110?

I'm wondering how many computers were based on the MC88100 and MC88110 processors that were released commercially. As of now, i've found the MVMe boards and Luna88K(+) computers exist, but that's ...
6
votes
2answers
785 views

Does the in-code argument passing conventions used on PDP-11's have a name?

Some subroutine calls on PDP-11 machines would be coded with the arguments appearing immediately after JSR or EMT instruction, something like this (apologies for not knowing the exact MACRO syntax): ...
6
votes
3answers
454 views

Can the Commodore 64 display 26 rows of text?

I seem to remember some demo, or a game, which displayed 26 rows of text (that's one more than the usual text mode resolution of 40x25). My memory of it is very hazy, but at least is corroborated by ...
1
vote
1answer
332 views

Identifying an old game from the early 2000s

I'm hoping this question belongs here as this is the closest site I could find that matched my situation. Many years ago, around late 2003 or 2004, I came across this electronic toy that sort of ...
6
votes
1answer
2k views

Is the NES controller port identical to the port on a Wii remote?

I was recently playing on a friend's NES Classic, and noticed that the controller ports look similar to the ones on a Wii remote (where you can plug in the Numchuck or Class Controller). Keep in mind ...
16
votes
3answers
4k views

Why did the Cray-1 have 8 parity bits per word?

According to https://en.wikipedia.org/wiki/Cray-1 The Cray-1 was built as a 64-bit system, a departure from the 7600/6600, which were 60-bit machines (a change was also planned for the 8600). ...
3
votes
0answers
235 views

Who developed the Super FX co-processor?

The Super FX co-processor was, according to Wikipedia and every other source I can find, a custom designed RISC chip made by Argonaut Games. Argonaut was a small British company and back in the late ...
4
votes
0answers
212 views

How many transistors in the Nintendo Super FX chip?

The Super FX coprocessor, released with Star Fox in 1993, provided 3D rendering capabilities that were absent from the SNES itself. Given that 3D gaming was quite widespread by the late eighties, it ...
1
vote
0answers
168 views

How much time does a Mac SE/30 with 128 MB of memory take for its power-on memory test?

I've read that it should be possible to push the SE/30 to its maximum RAM capacity with eight pieces of 16 MByte, 30-Pin SIMMs. I've never seen such a machine in the wild. Neither with 64 or 80 MB. ...
1
vote
1answer
243 views

'Swap file' on early time sharing machines

In the Wikipedia article for time sharing, it says The "state" of each user and their programs would have to be kept in the machine, and then switched between quickly. This would take up computer ...
6
votes
1answer
434 views

Does this computer have a steering wheel?

I don't really know what the round object is, but it certainly resembles an old-time steering wheel. This image was used as an example at this page. I don't know what its original source was, it is ...
18
votes
1answer
3k views

Did 5.25" floppies undergo a change in magnetic coating?

3.5" floppy disks, in the transition from 720K to 1.44M, changed the actual coating to a different compound that was magnetically 'stiffer'. This was necessary to support the higher density, but meant ...
6
votes
4answers
496 views

What is the origin of Mac OS X?

I think that Mac OS X is based on the Darwin OS, and the Darwin OS is based on the NeXTSTEP OS. Am I correct?
18
votes
4answers
3k views

Wanted: 5.25 floppy to usb adapter

I have found inexpensive (~$15) 3.5in floppy to USB adapter cables but have been unable to find a similar adapter for 5.25 floppy drives. Does anybody make such a thing? Are the pinouts of a 3.5 the ...

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