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11
votes
1answer
680 views

On the Z80, how can we use LD instead of JR?

The Galaksija ROM disassembly has a link to "A tutorial on how to use "ld" instructions instead of "jr" and save a few bytes in the process." My question is how does this work! It can see at l038ch ...
16
votes
2answers
1k views

How did the Trap65 work?

The Wikipedia page on the MOS 6502 mentions a hardware device called the Trap65 which apparently sat between the 6502 and its socket to trap any undocumented opcodes. The wiki page has the usual ...
11
votes
3answers
2k views

What was the first CPU with exposed pipeline?

Quoting from Programming for Performance exercise: early versions of the MIPS processor had an "exposed pipeline" (that is, the assembly language programmer needed to know the latencies of ...
14
votes
2answers
644 views

What were the 9 VAC pins used for on the Commodore 64 User Port?

I read that pins 10 and 11 are the 9V AC +/- pins on the Commodore 64 User Port. Pin 10 is the + phase while pin 11 is the - phase. I realize the User Port wasn't as versatile as the Expansion Port (...
7
votes
0answers
139 views

Gamepad triggers main menu in Fuse SDL

I'm trying to set up a gamepad to work with Fuse on Ubuntu. No matter which type of joystick I try to emulate (including None), pressing button #2 (or B in the Sega naming) opens the main SDL menu. ...
8
votes
2answers
1k views

Were any unlicensed games released for the Nintendo 64?

There haven't been many unlicensed games released for Nintendo consoles, partly due to the fact that Nintendo has locked down their development hardware and software. The most famous of Nintendo's ...
10
votes
2answers
332 views

What happens when a floppy track contains multiple sync words?

This question is specifically aimed to the Amiga hardware. Let's assume a floppy track is read via DMA using sync word to trigger the start. Let's also assume the track contains the sync word ...
15
votes
4answers
2k views

What graphical effects can be created by changing the VIC-II settings?

I read in this answer that one could create graphics effects outside the usual specifications of the hardware by changing the settings of the machine's VIC-II at specific cycles during the video ...
27
votes
5answers
3k views

Does every retrocomputer and console with NTSC composite output have 'artifact color' ability?

Artifact color is heavily associated with the Apple ][, since that is the only method the machine had to produce a color display. I was looking at the fantastic demo for IBM PC + CGA, 8088MPH, and I ...
12
votes
1answer
1k views

What is the relationship between the Ricoh 2A03 and the MOS 6502?

The Ricoh 2A03 (and the 2A07) is the CPU in the well-known Nintendo Entertainment System. Apparently, the die is very similar indeed, as the slides in this video suggest https://www.youtube.com/watch?...
19
votes
1answer
640 views

When was the relocatable object module invented?

During the time when programming was done in machine codes, there was no need for object modules; it just wouldn't make sense. People would write the whole program they needed to run in "zeroes and ...
9
votes
0answers
364 views

Who and how worked on games in 80's? [closed]

As a developer in a team, I am used to some techniques and workflow, like using git, issue trackers, linters, common ways to discuss the structure of the code, the ways to debug and refactor code. I ...
28
votes
8answers
7k views

NES cartridge ROM emulation with Arduino or Pi?

I'm looking to buy or make an NES cartridge that can be controlled by a microcontroller or small computer like the Raspberry Pi. I don't want to gut an NES cart and put an NES emulator inside it (as ...
37
votes
5answers
5k views

Why do programmable sound generators like SID include a noise generator?

In layman's terms, please explain the reason that all the popular PSG's used in 1980s computers and game consoles provided an additional channel to generate programmable "noise". How was this "noise" ...
18
votes
2answers
1k views

First computer emulator in Windows

I released my ZX Spectrum emulation Wspecem, and GPL sources first time publicly in the Internet at large, the 15th May 1996, for Windows 95. I am quite sure it was the first ZX Spectrum emulation ...
13
votes
2answers
776 views

NES repair - blue screen

I have an NES that was giving me a blinking red light when powering up. I had chalked this up to the 72-pin connector and set about cleaning it. After cleaning the connector and all games, the problem ...
19
votes
5answers
2k views

What was the first computer to support Arabic writing?

Looking at early microcomputers, all of them have support for something resembling ASCII, occasionally a few letters with accents and things were included also. And occasionally another alphabet such ...
10
votes
4answers
1k views

What was the first mass-market, 16-bit microcomputer system?

To qualify what I mean by "16-bit microcomputer system", I am talking about a system that has not only a 16-bit (or 32-bit) microprocessor CPU, but also a 16-bit wide external data bus connected to ...
11
votes
2answers
723 views

Acorn Electron to VGA/HDMI?

I am aware that there are answers regarding this but they do not seem to answer it for me. A few years back I got a Acorn Electron and it works using the arial for video fine, but I would like to ...
19
votes
3answers
3k views

Adjusting focus for old CRT monitors

I have an old Atari SC1224 CRT which has badly lost focus over the years. After taking the cover off, I can see various focus controls that can be adjusted by screwdriver. Question: is there a ...
8
votes
1answer
730 views

z80 CPU User Manual AND P/V Flag

I'm writing an emulator for the z80 CPU using the "z80 CPU User Manual" from zilog.com as reference. When I got into the AND operator I got confused. In the Condition Bits Affected is declared "P/V ...
4
votes
1answer
168 views

Include c files using z88dk

I want to split a program developed in c using z88dk in several .c files and I do not know how. I have these files: test.c: The main file with the "main" method. test2.c: An auxiliar file with the "...
7
votes
1answer
238 views

How do I use IBM Filing Assistant on DOSBox?

I would like to get specific step by step instructions on how to use an old word processor called IBM Filing Assistant on DOSBox to be able to access old 1980s documents. How to use DOSBox other than ...
9
votes
1answer
303 views

RS232 Tape Recorder Emulator?

I need to interface between an older system that uses an RS232 port for reading/writing to a tape and a more modern computer that can manipulate the data and send it back. Is there a software+hardware ...
6
votes
1answer
770 views

What pins on the PS2 AV out port are the audio pins?

I'm trying to get some LEDs to be synced with sound. I'm trying to find the pins for the left and right audio on a fat PS2 motherboard. All I can seem to find is a pin with a solid 10v and 2 pins that ...
22
votes
2answers
2k views

What are the “Screen Holes” in Apple II graphics?

I've read the term screen holes many times in the context of Apple II graphics. From what I understand, it has something to do with the interleaving storage of graphics (or was it text) and that some ...
10
votes
3answers
2k views

What is the name of the back arrow key on C64 keyboard?

What is the name of the back arrow key on top left corner of the C64 Keyboard? Is it escape or back? Also I don't recall using this key. What was the intended usage of it?
10
votes
3answers
2k views

Amiga-looking keyboard for PC

I would like to use an Amiga-looking keyboard on my PC. (I prefer not to use my old original A2000 keyboard with an adapter, partly because it lacks many keys present on modern 105-key keyboards, and ...
16
votes
2answers
596 views

Apple II: DOS 3.3 Virus?

Does anyone know the source of this Apple II DOS 3.3 virus that infected my disks back in the 1990's? I got it from a public domain disk collection that was given to me by a friend, called the ...
61
votes
11answers
16k views

Did Apple not originally allow anyone to develop software for the Macintosh?

This probably nearly belongs on Skeptics.SE but here goes. Within the last few years I've become an Apple convert for the most part, which occasionally brings me into (usually) good natured conflict ...
8
votes
0answers
370 views

Did the Apple ][ ever ship with the Autostart ROM

Did the Apple ][ ever ship with an autostart ROM from the factory or were they all the older ROM with Trace/Step? My guess would be that once the ][+ started shipping then new Apple ][ production (...
5
votes
2answers
597 views

What does the blinking of the cpu address bus actually means?

I'm currently running NOP on a Z80A cpu. All it does it flash some led, I expected it to flash 1 by 1. The led are place from address 16-0
9
votes
2answers
2k views

Was it Microsoft that started the war between Application and OS vendors?

I think there is a long history of application vendors going to great lengths to complain or litigate against Operating System vendors to compete fairly. Specifically, I am talking about "fairness" ...
5
votes
1answer
134 views

Where are program datas stored on Windows Mobile 5.0?

I am probably a decade late with this question, but anyway. I digged out a PDA with Windows Mobile 5, and installed SpaceTime Mathematics on it. It is a 30-day trial (and you can't purchase the ...
10
votes
1answer
1k views

Which C64 games support two buttons?

CIA 6526 chip used in Commodore 64 is capable of controlling two separate joystick buttons. But the second button should be connected through paddle pot input. This option was not popular till the ...
25
votes
5answers
9k views

Windows 98 with 2GB of RAM

I have assembled a retro-gaming PC out of an old Shuttle SN45G with a Windows 98/Windows XP dual boot. The motherboard can handle 2GB of RAM, but apparently Windows 98 can only handle 1Gb. Windows ...
10
votes
2answers
273 views

Order of powering down Atari ST and hard drive?

I am wondering if the order is important, which do I turn off first? The Atari ST computer or the external hard drive attached to it? It is on an SCSI adapter.
8
votes
2answers
426 views

What operating systems allowed arbitrarily-sized disk blocks?

According to my limited experience with IBM clone mainframes, and as far as I can remember, at least in one OS the permanent storage disk space was allocated to users (and the scratch space — to ...
9
votes
2answers
2k views

Documentation on Windows Explorer Shell Command Files

Windows Explorer Shell Command Files are a feature added to Windows with Internet Explorer 4 (95 / NT 4). They were used in the now-defunct Quick Launch bar to show the desktop, open IE4's Channels ...
2
votes
1answer
976 views

What systems used hard sectored floppy disks?

Which computer systems used hard sector indexing of floppy disks? Background: On 5 1/4" and 8" disks there is a hole punched into the disk used for optical timing to locate the start of sectors. ...
18
votes
3answers
826 views

Did the Apple IIe Platinum include all feature enhancements from the Apple II line?

Not including the Apple IIgs, did the Apple IIe Platinum include all enhancements made by Apple? For example, the first Apple IIe couldn't utilize the Double Hi-Res mode from what I understand. In ...
10
votes
1answer
311 views

Apple II SCSI: Maximum drive / partition size?

Using an "SCA to 50-pin adapter", it is possible to use a 300 gig Ultra-320 SCSI drive from 2004, with an Apple II outfitted with the Apple SCSI controller. It seems possible for the electronics to ...
10
votes
1answer
397 views

Does this Nova rack have historical value?

I wish to modify my rack, in order to mount some modern rackmount servers. Am I damaging a piece of history and will incur the wrath of historical computing librarians ? It is an old 19" rack that ...
8
votes
3answers
8k views

How can I upscale the video output of a Nintendo 64 for low-latency and high quality graphics on an HDTV?

Say I want to hook up a Nintendo 64 console to an HDTV via HDMI or Component. What are my options for upscaling hardware to be able to play the system without low quality or blocky picture and with ...
31
votes
2answers
3k views

How did “Ballblazer” pull off fast, smooth, first-person, solid-model 3D on Atari 8-bits?

I remember the first time I saw Ballblazer, the 1984 game, running on a friend's Atari 800. The split-screen 3d graphics and fast action blew my socks off. Looking back, I get the impression there ...
7
votes
2answers
6k views

Windows 98 / XP Dual boot

I have acquired an old Shuttle X PC (Windows XP, Mini-DTX form factor HTPC) that works fine. As I can't do much with this form factor (I can't fit a modern motherboard in the case) and that the ...
45
votes
4answers
7k views

Why would older video games include fragments of source code?

One thing that was surprisingly common in older video games (around the same era assembly language was king) was the inclusion of uncompiled, plaintext source code in the ROM. You can see many ...
13
votes
3answers
627 views

Can the CSG 65CE02 CPU be used to accelerate an Apple //e or //c?

The CSG 65CE02 is an improved 6502 microprocessor that was shipped in small quantities by Commodore around 1988. It is used in the Amiga A2232 multi-port serial controller card, and that would be the ...
10
votes
1answer
915 views

What was the significance of the cursive 'ƒ' in an application name?

I feel like I used to know the answer to this... In classic Mac days, probably the early 90s and before, some applications would have a cursive / decorative ƒ character in their names. What was the ...
10
votes
3answers
353 views

Will careful restoration of a retrocomputer's paint job enhance its value?

First off, I'm not talking about painting my plastic C64 in Ferrari Red! While this may look cool, I'm sure any value enhancement of the machine would be based purely on 'taste'. I have a NeXT Cube, ...

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