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12
votes
1answer
333 views

Xerox Parc and the three-button mouse

The original GUI invented at Xerox Parc, used a three-button mouse. What did each of the three buttons do?
3
votes
1answer
211 views

Trying to open IBM FILING ASSISTANT in DOSBOX, or other? [duplicate]

How does one get a program like a word doc onto MS DOS to begin with? I have a set of files that are backups, only one with .exe that is from an ancient word processor and would eventually like to ...
0
votes
3answers
736 views

Does anyone have the source code of an early program written in Assembly? [closed]

I am interested in looking at the source code of any program that was written in Assembly just about when the Assembly language was invented. If anyone have a source code for such a program, please ...
11
votes
1answer
1k views

What ended the Sony console partnerships with Sega and Nintendo?

Sega and Nintendo were the dominant players in the console market at the end of the 1980s and into the 90s. By early in the next decade, Sony shipped the PlayStation 2, leading Sega to exit the ...
8
votes
1answer
134 views

cbm prg studio for the Amstrad

CBM prg studio is brilliant. I have searched Google for a version (or something similar) for the Amstrad CPC 464, to no avail. Does anyone know of one?
5
votes
1answer
195 views

Amstrad CPC 464 tape deck loads, but makes grinding scratching noise

I'm concerned about an Amstrad CPC 464 tape deck, which loads, but makes grinding scratching noise while rewinding, fast-forwarding and play. Sometimes it does load silently, but after a subsequent ...
8
votes
1answer
308 views

How did WebTV (MSN TV) work

Wikipedia says: The WebTV product was an adapter that allowed a television set to be connected to the Internet, primarily for web browsing and e-mail. The setup included a web browser, a corded or ...
11
votes
1answer
652 views

What is the proper way to test the PSU output for a Commodore 128D?

This question is directly related to comments on the more general question and answer here. The Commodore 128D and 128D-CR have an internal PSU that can be readily and safely disconnected from the ...
45
votes
4answers
3k views

What precautions to take when powering on old computer for the first time in years

I have a Commodore 128D that hasn't been powered in about 15 years. I want to begin using it again. It has been stored in cool dry places like attached garages, in a cardboard box. I hope this ...
5
votes
0answers
186 views

Manual for DIAGNOSTICS II V1.2 - CPU TEST SUPERSOFT ASSOCIATES

I am building a 8080 emulator. I found some useful test suites here. The emulator passes the first test suite (8080/8085 CPU Diagnostic, version 1.0, by Microcosm Associates), but not the second ( ...
8
votes
1answer
846 views

128-bit floating point

IEEE 754 defines 128-bit floating point, though perhaps in a three-way chicken and egg problem, it's rarely supported by hardware, rarely supported by compilers, and rarely used. Have there been, ...
12
votes
2answers
530 views

Is this machine the EDVAC, MANIAC, or IAS?

See the image. Different sources claim that this machine is the EDVAC, MANIAC I, or IAS. For example, the Wikipedia page on John von Neumann has a picture of him and J. Robert Oppenheimer standing ...
12
votes
1answer
289 views

What is the difference between i8080 and i8080a?

There is some info over the net regarding 'some i8080 bugs were fixed in i8080a', but the exact bugs and differences are not usually disclosed. So, what is the exact difference between i8080 and ...
8
votes
1answer
194 views

How to disable existing, unknown, password from AppleTalk on MacOS 7/8?

My Grandparents computers are connected to each other via an ethernet cable, and communicate via AppleTalk. One of the computers is an iMac G3 with Mac OS 8 and the other is a "SuperMac" from the ...
6
votes
3answers
1k views

Atari 800XL, black screen on power on - how to diagnose the problem?

I've got an atari 800 XL that is broken - when I power on, there's no reaction. It seems there is at least something sent to display, as TV detects a signal, and turns full black. The chips are ...
17
votes
1answer
2k views

Was it possible to get more than 8 sprites per scanline on an Amiga with the copper list?

I've read in the past that it was possible to overcome the 8 sprites per scanline on the Amiga (OCS) using the copper list. However, I can't seem to find any actual references to what may have used ...
15
votes
3answers
3k views

6510 clock rate of C64: Why was it considerably slower than the 6502 of the Atari 800?

According to Wikipedia, the Atari 8 bit series had a 6502 running at ~1.8 MHz. Why was the clock speed of the 6510 for the C64, which was designed a couple of years later, considerable slower? Was the ...
12
votes
6answers
2k views

Memory-limited workloads

I'm trying to figure out whether computing workloads, particularly those related to science and engineering, have historically been limited by memory or CPU. (By the former, I mean not memory access ...
7
votes
2answers
570 views

Can I power a z180 with 3.3v [closed]

I'm planning to buy a Z8018006PSC. A z180 CPU (which I found is compatible with the z80 and has some advantages, for instance, able to address up to 1MB of RAM). I'm planning to use it together with ...
21
votes
3answers
2k views

Why did the Atari 800 designers choose such a radical system design?

The physical system design of the Atari 800 was pretty radical, when compared to the 3 other canonical home computer designs of the late-1970s: TRS-80 Model 1, PET, and Apple ][. As the photo of the ...
4
votes
2answers
396 views

Cost of tape backup in 1980

How much did it cost in 1980 to buy a tape drive capable of backing up 5 megabytes of data? Both for the drive itself and per tape? (If that exact data is unavailable, I'd be interested in something ...
19
votes
1answer
787 views

Which computers had features added purely for tax reasons?

I was recently reading about the Amstrad CPC 472, which was a CPC 464 with an extra, unusable 8KB of RAM added to avoid Spanish import fees on computers with 64KB or less. Did any other computers have ...
3
votes
0answers
215 views

How many CP/M machines ever shipped? [closed]

How many machines for which CP/M was the primary operating system (so not counting the Commodore 128) ever shipped? I would also be interested in knowing how many S-100 machines ever shipped. I get ...
23
votes
4answers
12k views

Why did Mac OS 7 perform poorly with virtual memory enabled?

A comment in another question about supervisor and user modes in the Motorola 68000 processors, claimed that "performance was abysmal" with virtual memory enabled. An InfoWorld article about System 7 ...
14
votes
3answers
2k views

How do you recognize an early production model Commodore 64?

The Commodore 64 was the most popular single retro-computer produced, probably selling something like 15 million units. Clearly, the C64 is not "rare", but early revisions from 1982 are highly prized ...
12
votes
1answer
598 views

What was the first dedicated core router?

From 1969 up through the early 80s, the Internet used general-purpose Honeywell minicomputers for its core routers. At some point after that, purpose-built machines started being used. What was the ...
31
votes
4answers
5k views

What was the IBM PC cost saving for using the 8088 vs 8086?

The decision to use the 8088, a version of the 8086 with the data bus restricted to 8 bits, in the original IBM PC, seems strange on the face of it, certainly hurt performance and intuitively shouldn'...
14
votes
7answers
1k views

Did any system natively use 3-bitplane graphics?

Computer and game consoles switched gradually from single-bitplane graphics (2 colours per character) to 2-bitplane graphics (4 colours per character), to eventually 4-bitplane graphics (16 colours ...
15
votes
3answers
1k views

How did the original Apple Macintosh and Atari ST use protected mode?

The Macintosh, ST, and Amiga were all 68000 CPU systems released in 1984-85, along with their respective new Operating Systems. While this was 5 years before protected mode became commonplace on Intel ...
16
votes
4answers
921 views

Best way to locate data on ROM? (6502 Processor)

Lately I've been interested in how old machines work, in particular an NES. While there are quite a few resources on the basic operations and even some games that have been totally broken down byte by ...
7
votes
2answers
350 views

Is there anything special about /dev/console?

I am using the SimH emulator to emulate a PDP-11 computer with UNIX V7 installed on it. So basically I am emulating something like this: I issued the tty command to see on which TTY port my terminal ...
11
votes
2answers
299 views

How did the early UPC barcode readers work?

According to the history of barcodes, the idea of consumer product barcodes appeared before the microprocessor era. What was the implementation plan then? Would each store need a mini-computer in a ...
6
votes
2answers
567 views

Does ancient UNIX create a new shell process for each terminal?

In Linux, each terminal is associated with a new shell process. For example, here I have two xterm terminals, and each xterm terminal has an associated shell process: I am wondering if in the old ...
24
votes
3answers
3k views

Is there any advantage of a ceramic microprocessor over a plastic one?

Looking at this page which refers to the initial release of the Z80 microprocessor, it prices the ceramic one at $65 versus the plastic version at $59. I know that at least with the 6502, the ...
6
votes
3answers
859 views

Is the SimH emulator available on macOS?

Is the SimH emulator available for macOS? I can't find it on their website: http://simh.trailing-edge.com/ What I am specifically interested in is to run UNIX V7 on a PDP-11 emulator.
4
votes
1answer
485 views

How much did different kinds of ports cost to add to a 1980's home computer? [closed]

These days it's mostly converged on USB, but in the old days computers tended to have lots of different kinds of ports. In particular, I'm interested in: 9-pin serial 25-pin serial parallel printer ...
10
votes
3answers
387 views

Will using a clockport RTC card on an Amiga 1200 clash with the RTC on an accelerator card?

I have an accelerator card fitted to my Amiga 1200. The accelerator includes a real-time clock, but I noticed that the soldered-on rechargeable battery was in danger of leaking, so I cut it off before ...
13
votes
3answers
2k views

How much did the 6502 and Z80 cost?

It is said that the 6502 was cheaper than the Z80. As of 1978, what were the actual prices of the two chips, in wholesale quantity?
9
votes
1answer
416 views

When were the various frequency Z80 CPUs introduced?

The Z80 was introduced, as I understand it, at a clock speed of 2 MHz. Later, Z80-based computers at 3.5 MHz started showing up. In what year did this faster clock speed become available? (In ...
9
votes
1answer
191 views

How does ProDOS allow for multiple volumes to exist on a single device?

On the back of this question, it got me thinking that it has always been that ProDOS would only support a ",D1" and ",D2" on a slot, i.e. slot 6 would have two addressible drives. With my 20MB Sider ...
5
votes
3answers
2k views

9-pin port for both RS-232 and Atari joystick?

A 9-pin RS-232 serial port looks superficially quite similar to the Atari joystick port. I don't suppose you could just plug a joystick into a serial port and have it work, but suppose you took this ...
11
votes
2answers
1k views

Which Apple floppy drive is compatible on both Apple IIc and Macintosh

I have an old Apple IIc (not Plus) and an old Macintosh Plus (1MB RAM). I want to buy an external 3.5 inch floppy drive that works on both machines, that way I don't need two different drives around ...
7
votes
1answer
1k views

What is the maximum BAUD rate for ZX Spectrum tapes?

I've played with various BAUD rate programs that allow you to save most of the RAM into a cassette tape up to around 9600 BAUD. Has anyone written or have a way to write the ram to tape (not ...
11
votes
2answers
737 views

How does the Amiga chipset RGA bus work?

The RGA bus is the bus that connects Agnus/Alice with Denise/Lisa and Paula. What is it used for? I guess at a minimum to write/read registers in Denise/Lisa and Paula, and I guess to feed data to ...
5
votes
0answers
274 views

Find the PGP SDK

Starting in 1998 (I think) the PGP company run by Phil Zimmerman released the PGP SDK for Mac, Unix and Windows. This was a big event because it was the first time that comprehensive, high grade ...
19
votes
5answers
2k views

Cloning circuit boards for antique computers?

Would it be feasible to create direct clones of obsolete and increasingly hard-to-find motherboards and controller boards for vintage computers? Most of the early 1980s technology was either single ...
9
votes
2answers
186 views

Apple II: ProDOS partitions on floppy disks?

On the Apple II using ProDOS, was it possible to create partitions on a floppy disk? Would it be possible to have two or more partitions on a 140k 5.25" or 800k 3.5" disk? (The question here is not ...
9
votes
1answer
182 views

Apple II: What type of partition tables were used?

What type of partition table was used with ProDOS? ProDOS (8-bit) version 1.2 was available in January 1983, one year before the Macintosh was released, so it is unclear to me if ProDOS 1.2 used the "...
6
votes
4answers
368 views

What was the first personal computer to use surface mount components?

Title pretty much says it all. To qualify, the computer must have been manufactured and released. No prototypes or computers that never shipped. Also, I'm looking for computers used at a home or ...
4
votes
2answers
397 views

Does the “backspace” key places the cursor on a new line in UNIX V7?

I am running UNIX V7 using the SimH emulator. Whenever I press the "backspace" key, instead of the previous character being deleted, what happens is that the cursor is placed on a new line. Is this ...

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