All Questions

Filter by
Sorted by
Tagged with
1
vote
2answers
73 views

What was the DEC Type 30 vector graphics display used for?

The DEC PDP-1 had, unusually for its time, a vector graphics display. According to https://en.wikipedia.org/wiki/History_of_Digital_Equipment_Corporation Most systems were purchased with two ...
5
votes
3answers
2k views

Why was the Kickstart 1.x “Insert floppy” graphic so bad?

Anyone who used an pre-Kickstart 2.0 Amiga will be very familiar with the "Insert Workbench floppy" image: I realise that this is subjective, but the image has always stuck me as ... well, a bit ugly....
11
votes
2answers
974 views

Apple II GS versus Mac Plus cost

I just came across a fascinating video https://www.youtube.com/watch?v=7h4tepFbMso&t=78s which makes a coherent case - I don't feel I can pass a final verdict on whether he's right or wrong, but a ...
16
votes
4answers
3k views

Were there any 8-bit CPUs with 24-bit addressing?

Or was that something that didn't appear until later CPUs (around the time of the 286 maybe)? Also, how would I go about researching this on my own? It's not exactly something I can look up on ...
10
votes
1answer
494 views

Was the Mac XL hardware different from the last versions of the Lisa?

The Lisa was a fairly impressive platform for the day. In comparison to the original Macintosh, the two did have different displays and aspect ratios but the Lisa also had additional hardware such as ...
1
vote
0answers
132 views
+50

How many Amiga 590 units were sold?

The A590 was an external hard disk for the Amiga 500, in 'sidecar' form factor, that could also hold an extra megabyte of RAM. How many 590s were sold, throughout its life?
1
vote
1answer
103 views

How to configure NETWORK and TCP on a DOS VM

I'm trying to install and use the Arachne broswer under DOS (6.22). I've DOS installed on VirtualBox VM (5.2.34) under Linux Ubuntu (4.15.0-88-generic #88-Ubuntu). I'm in trouble in configuring ...
3
votes
7answers
396 views

Static memory partitioning

Does anyone know of any operating system that used static memory partitioning: contiguous physical memory allocation with one process per partition, one partition per process, partitions generated at ...
16
votes
3answers
3k views

Are pixels on the Commodore 64 square?

Are "tile pixels" the same size as "sprite pixels", and are they both square (ignoring the rule that multicolor sprites can only be colored in groups of two pixels)? By "square" I mean that the ...
17
votes
4answers
4k views

Why not one pixel per color clock?

Early home computers and game consoles output video to TV sets. The NTSC color clock frequency is 3.58 MHz. This informed the design of some video systems: http://pineight.com/mw/index.php?title=...
-4
votes
0answers
72 views

Making a Z80 Based Cyberdeck [closed]

I’m looking into building a modular Z80 based cyberdeck and I was wondering how one would go about building one. I was thinking of something like an Atari 800 in a 2’x8”x3” case. It would have a ...
7
votes
1answer
236 views

Fixing an ailing Amiga 500

My old Amiga 500 has been living in its box for the past 20 years and does not function as it should. When turned on initially it seems to work fine, loads the Workbench disk and allows me to open/...
8
votes
1answer
419 views

Price of early color monitor versus TV

Some computers in the seventies and eighties had the option of output to either a TV or a dedicated monitor. Suppose repurposing an existing TV isn't an option and you are going to be buying a screen ...
8
votes
2answers
1k views

What was the first computer malware that could infect Mac systems?

The number of malware that can infect Mac computers has increased significantly last decade (2010-2019), particularly scams (including tech support scams) and fake anti-malware apps. since when ...
25
votes
7answers
6k views

What is the reason the 8051 was not used in 8-bit computers?

The 8051 is a Harvard-based microcontroller, but it allows us to connect external memory and simulate von Neumann's architecture. What is the main reason it was not used widely in 1980s home computers?...
1
vote
1answer
71 views

Exit NitrOS9/OS9 EDIT command without saving file

NitrOS9 is a modern clone of the original OS-9 operating system used on the coco3. Both OS-9 and NitrOS9 have an EDIT command, a line-based text editor. As far as I know, EDIT works the same in both....
5
votes
1answer
294 views

Why did the Sinclair QL keyboard lack a Delete key?

Reference: picture at https://en.wikipedia.org/wiki/Sinclair_QL It seems like an odd key to omit, given how frequently used it is and given that both the Spectrum + and 128 have one, which acts like ...
7
votes
2answers
328 views

How to pass data pointer to subroutine to use with Absolute,Y addressing?

I may be going about this the wrong way, so sorry if it is wrong, I'm coming to 6502 after 32 years (when I was 8 years old !) I want to pass a pointer to some data, either data1 or data2 to a sub ...
8
votes
4answers
3k views

Is it possible to swap the Apple //c's monochrome CRT tube for a color one?

I just love the Snow White industrial design language of the Apple //c, especially when paired with the Monitor //c. It is a classic design that doesn't show its age. I've even recently seen them ...
2
votes
2answers
155 views

How fast did the ARM-1 access memory?

The ARM-1, an early 32-bit RISC CPU, was used in the Acorn Archimedes computers, released in 1987. Its rated speed was one 32-bit instruction per cycle at 8 MHz. Typical RAM chips at that time would ...
7
votes
1answer
284 views

What are some early network file systems?

I know it's always hard to define an exact first, so I'll just ask about early network file systems. To be more specific, I'm wondering about file systems that transparently present directories and ...
7
votes
4answers
803 views

Was there any particular reason the 6502's LDX#imm and LDY#imm aren't opcodes A8 and AA?

Parts of the 6502 opcode map are fairly regular, and parts of it aren't. One bit that strikes me as really weird is the decoding of LD_ instructions, in relation to the decoding of other ALU ...
28
votes
17answers
8k views

Was it possible to listen to music and work on old PCs? When was it possible to for the first time?

I was wondering the other day, would it be possible to listen to a midi on a C64 while writing a program or something. I mean it did have a sound chip that would technically just get some new buffers ...
4
votes
1answer
153 views

pfs3 error when copying files

Config: WinUAE 4.2.1, CPU 68020, 24bit, FPU 68882, 8MB FastRam Z2, A1200, CF 4GB Transcend, BetterWB 43, Dopus 4, When I try to copy folders from PC to CF Partition (2.4GB, pfs3) it goes alright, ...
6
votes
3answers
1k views

How do I configure a V6366 graphics controller for 640x400 B/W?

I have here a Schneider Target PC 7640 which is an early PC AT compatible laptop. It features a 640x400 plasma screen with 32k display RAM driven by a Yamaha V6366 B-F graphics controller. I was ...
32
votes
13answers
8k views

Did anyone ever use the extra set of registers on the Z80?

The Z80 has the surprising feature of a second set of registers. I suppose these were intended to be used for rapid task switching or interrupt handling, though I think if I were programming a Z80 ...
10
votes
1answer
805 views

Difference between Intel 8087 and 8089 opcodes

The 8087 floating-point coprocessor presumably used different ESC codes to the 8089 input/output coprocessor, since then they would be able to listen over the bus for their own ESC instructions. The ...
13
votes
4answers
2k views

Amiga 500 OCS/ECS vs Mega Drive VDP

Superficially the Amiga 500 and Mega Drive are similar. Both run a Motorola 68000 CPU at similar clocks and both have dedicated hardware for sprite and other graphics operations. Comparing the arcade ...
37
votes
5answers
9k views

Apocryphal (?) tale of hard drive platter propelled through a wall?

In the mid-1990s while a student at a US university during a computer science lecture, my professor (not a TA or grad student) told us a story of "witnessing" a large, then old-fashioned metal hard ...
7
votes
3answers
505 views

How do I adjust the OS print output to different screen dimensions on VIC-20?

The graphics chip of the VIC-20 has a setting for the number of columns and the number of rows to display. So, instead of the default values of 22 columns and 23 rows, for example, it is possible to ...
4
votes
2answers
382 views

Why were the Cell SPEs unable to operate without instruction from the PPE? [closed]

The Cell, the CPU of the PlayStation 3, contained one conventional core called the PPE, and up to eight specialized vector cores called SPEs. According to https://en.wikipedia.org/wiki/Cell_(...
9
votes
1answer
199 views

How can slot 1 of the Apple ][ replace the keyboard?

Nick Westgate posted a comment a few years back on a question about how slot 7 was unique stating that "Slot 1 on the //e is also unique - it can be used to replace the keyboard". What was it about ...
3
votes
2answers
148 views

Are there Commodore BASIC 7.0 music demos?

Commodore BASIC 7.0 that came with the Commodore 128 provided commands for playing music notes and setting different instruments. The play function even had a feature that played a note in the ...
10
votes
3answers
1k views

How to use rounding with 6809 multiplication

The MC6809 is unusual for an 8-bit processor of its era in having a hardware multiply instruction. MUL multiples the 8-bit unsigned integer in the A register with the 8-bit unsigned integer in the B ...
6
votes
1answer
1k views

Did GBA “load” from the cartridge, or was it read in real-time?

Older systems, such as the NES, would often access the ROM in real-time rather than caching the data in system memory, sometimes even reading the same data every single frame. This would result in an ...
2
votes
1answer
158 views

When first CMOS versions of Z80 became available and were they ever used in (non-portable) home computers?

When Z80 first became available on the market in 1976 it was made using NMOS technology. It is the version that is likely to be most familiar to people interested in retro-computers. For example, to ...
9
votes
3answers
2k views

Role of the Z80 co-processor in GBA games

The Nintendo Game Boy Advance had a Z80-like processor which was typically used for backwards compatibility with GB and GBC games. According to its Wikipedia page, an uncited comment claims that the ...
7
votes
2answers
842 views

When was DEFUN added to Lisp?

I don't see DEFUN in a ~1966 copy of PDP-6 LISP. I do see it in a 1972 Maclisp. AI memo 116A from 1967 doesn't have DEFUN. (It does have MACRO.)
14
votes
2answers
722 views

Does the Z80 allow interrupts after processing and ignoring a 0xdd prefix?

I read here that if the Z80 encounters e.g. multiple 0xdd prefixes in sequence, for each 0xxdd except the last it acts almost like a NOP, but does not allow interrupts to occur immediately after "...
16
votes
5answers
4k views

Why did the Z80 with 4-bit ALU out-perform the fully 8-bit Intel 8080?

Looking at the development and architecture of the Z80, it appears to be a scaled-down, cost-reduced (in terms of total system cost), clone of the Intel 8080. It only used a 4-bit ALU. I assume this ...
52
votes
3answers
12k views

Who set the 640K limit?

We all know that "640K should be enough for everyone". But who actually set this limit? The quote is often attributed to Bill Gates, but it doesn't seem like a decision for an Operating System vendor ...
3
votes
1answer
250 views

Origin of “640K RAM is enough” quote

Yesterday I was digging through a rather long directory path to watch an episode of Fist of the North Star (on Windows 8.1) when I was hit with an error message: The path name is too long I looked ...
36
votes
6answers
9k views

What limited the use of the 6809 CPU in personal computers?

Why did manufacturers of home computers avoid using the 6809 CPU? I realize that the Z80 and 6502 had a 3- or 4-year head start in availability. But once it did become available in 1978, I don't ...
5
votes
1answer
512 views

Minimal DOS long filename driver

Am trying to run Latex + Emacs under DOS 5.0, and would currently seem to need long filenames. I have tried the DOSLFN driver but it prevents Emacs from running. I have 4 MB RAM in total. Is there ...
0
votes
1answer
89 views

How is the LCDC (LCD Control) register manipulated on the Gameboy?

I don't see it listed anywhere in the 0000-ffff address space. Is it controled by the CPU? Or something else entirely?
1
vote
1answer
94 views

Can I connect a Sega Megadrive or Genesis to an Amstrad Cpc monitor?

I'd like to buy an old Sega Megadrive, aka Genesis outside the UK. However I don't have a TV or computer monitor to view the graphics on. I do however have an Amstrad Ctm644, which is a 15Khz CRT ...
19
votes
3answers
2k views

Do all VGA cards implicitly support CGA and EGA?

Practically speaking, if I buy an ISA VGA card, will it implicitly support CGA and EGA games?
-1
votes
0answers
60 views

Why must function declarations be followed by brackets when no parameters are passed? [migrated]

I understand that in many programming languages, function routines have what I can generally name a "default array", usually symbolized with parenthesis and if it is not empty, it is utilized in ...
4
votes
3answers
649 views

What were some of the earliest common webservers and how did they work? [closed]

And by Web server I mean actually web server (not BBS), meaning it had to run on the actual IP internet and be browsed with a dedicated browser program. So what kind of tools were used in the late 80s/...
2
votes
1answer
60 views

What was the last of the Thinkpad X series with replaceable RAM? [closed]

I know my x230 has replaceable RAM. I know the x395 lists its ram as being soldered. What is the last of the X series lineup with user-serviceable RAM?

15 30 50 per page
1 2 3 4 5 59