All Questions

198 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
19 votes
0 answers
1k views

Oxford C compiler for Commodore 64

I kept one floppy from my Commodore 128 (which I used mostly in C64 mode), labelled ‘Oxford C compiler’. It is a 5.25″ floppy. Don't ask me why I kept just this one; probably because I thought I ...
user avatar
16 votes
1 answer
502 views

When was an image of an apple first used to promote the APL language

The APL community is contemplating the adoption of a common logo but some are worried about trouble from Apple lawyers. Now, IBM and others have been using apple motifs in promoting APL for a long ...
user avatar
  • 559
15 votes
0 answers
360 views

Uninstalling OS/400 by deleting one program

This is about the AS/400 which is an IBM mini-computer launched in 1988. It lives on today after several name changes and considerable hardware and software changes. It is still often informally ...
user avatar
  • 1,812
15 votes
1 answer
427 views

Why did the 8080's PUSH PSW write one reserved bit as 1 and the other two as 0?

The x86 "flags" register, which holds condition codes and other processor status bits, has several reserved bits with fixed values, but these fixed values are not all the same. In ...
user avatar
  • 359
13 votes
0 answers
190 views

68060 CLKEN and CLK pins

Using an 68060 to 68040 Amiga adapter on another brand. The adapter ties the 68040 BCLK to the 68060 CLKEN. The CLK pin on the adapter is left floating. To run the CPU with 1/2 bus will I need to ...
user avatar
  • 131
13 votes
0 answers
507 views

What is the protocol for bootstrapping a Game Boy Advance over a link cable?

One of my favorite features of the Game Boy Advance growing up was the ability for some games to be played multiplayer with just one cartridge - the first player would have the cartridge and all the ...
user avatar
13 votes
0 answers
360 views

Unix on the H11?

I'm curious if anyone is aware of actual uses of Unix on the Heathkit H11? I don't see any technical reason a memory-expanded H11 couldn't run Unix, but can't find any examples of it doing so.
user avatar
13 votes
0 answers
524 views

Who owns the intellectual property of Thinking Machines today?

Who owns the intellectual property regarding the Connection Machine and other products from Thinking Machines? I believe the remnants were bought by Sun, so possibly Oracle, but does anyone know?
user avatar
13 votes
0 answers
458 views

Is there a simple BASIC program that demonstrates SID6581 distortion?

Many songs use a SID6581 design "flaw", distortion, as an effect. I tried experimenting with the filter and resonance registers, but was unable to reproduce the sound. What conditions are necessary ...
user avatar
  • 2,215
13 votes
0 answers
866 views

In search of.... SeaWar -- NOT Battleship!

Hopefully, sufficient background Many years ago (40-45), I used to play "Sea War" on a good sized time-share system. It was a text/adventure war game between a couple remote players, played over a ...
user avatar
12 votes
0 answers
221 views

Was there a hard disk type that had a SMART overflow crash/bug?

A data center employee told me a story about 25 years ago, explaining why that data center took some time to assemble a RAID array. Recently, I wasn't able to verify the facts by googling, and I may ...
user avatar
12 votes
1 answer
378 views

What are these compression types in the ARC file format?

The file format of the SEA ARC compression tool, also used by the PKWare PKARC tool, allowed the following compression types: Packing (RLE encoding) Squeezing (static Huffman coding) Crunching (LZW)...
user avatar
  • 16.4k
11 votes
0 answers
341 views

Was the RPL language for the Commodore PET ever used other than by its author?

Note that this question is about the programming language RPL for the Commodore PET, not the HP language with the same name. RPL was developed by Tim Stryker and sold through his company Samurai ...
user avatar
  • 891
11 votes
1 answer
622 views

1990s BBS game featuring mining elements from a planet

Sometime in the 90s (sorry, can't be more specific) I used to dial in to a BBS and play a multi-player game that involved manually mining elements from a planet. It was very detailed, you got employed ...
user avatar
11 votes
0 answers
1k views

Why is the original Altair BASIC (for the 8080 CPU) source code not available on-line?

As described by The Register in 2001, around 1987 journalists and others started asking Bill Gates for a copy of the source code for the original version of Altair (eventually Micro-Soft) BASIC, ...
user avatar
  • 21.9k
10 votes
1 answer
401 views

Could the N64 have supported more than 8MB of RAM

The N64 came with 4MB of RAM soldered on the board. With the Expansion Pak, you could add an additional 4MB of RAM to bring it to a total of 8MB. Was 8MB the maximum amount of RAM that the N64 could ...
user avatar
  • 963
10 votes
0 answers
277 views

Everex Systems EV1250: Perhaps a 286 accelerator? I need its manual

Recently I got an unknown card named EV1250 that I couldn't find any information on what it was. I assume it's probably a 286 accelerator. There are some memory chips on the left side of the card and ...
user avatar
  • 151
10 votes
0 answers
191 views

Which versions of StuffIt introduced backwards-incompatible changes to the file format?

In order to help people who want to integration-test tools which shell out to The Unarchiver's lsar and unar utilities, I'm trying to build a legally clean repository of test archives in StuffIt SIT ...
user avatar
  • 4,563
10 votes
0 answers
242 views

What happened to the Speakeasy computational environment?

After reading his interview with the Computer History Museum , Cleve Moler (creator of MATLAB), mentioned that the Speakeasy Computational Environment was a precursor to MATLAB, and served as some ...
user avatar
10 votes
1 answer
438 views

Was there a cartoon series in the UK computer press called "Computability Brown"?

My dad was a computing professional in Scotland in the 1970s. He received a couple of industry trade magazines every week, such as Computer Weekly and Computing. In one of them, I remember there being ...
user avatar
  • 17.2k
10 votes
0 answers
475 views

How would toggling a bit in the POWCNT1 register cause hardware damage on the Nintendo DS?

From GBATEK, writes to a certain I/O port for power management may damage hardware: 4000304h - NDS9 - POWCNT1 - Graphics Power Control Register (R/W) 0 Enable Flag for both LCDs (0=Disable) (...
user avatar
  • 1,830
10 votes
0 answers
323 views

How much did Atari pay for GEM?

Atari licensed Digital Research's GEM graphic user interface for the ST. As https://www.filfre.net/2015/04/the-68000-wars-part-2-jack-is-back/ puts it: And of course in the wake of the Macintosh the ...
user avatar
  • 49.6k
9 votes
0 answers
198 views

Plessey computer at Stanford?

While updating the wiki article on the 4004, I came across an interesting claim by Ted Hoff, who stated the idea of using a general-purpose CPU in a calculator came to him due to a minicomputer that ...
user avatar
9 votes
0 answers
256 views

Looking for late 90s shareware open world racing game

I'm trying to track down a shareware racing game released somewhere between 1999 and 2004 - or at least, my parents found it bundled in a computer magazine during that time. Here's what I remember ...
user avatar
9 votes
0 answers
291 views

Undocumented ModR/M byte combinations

The reason I am asking this question is because I was trying to compile a list of all 8086 opcodes, regardless of whether or not they are documented. The list is just for fun, the documented opcodes + ...
user avatar
  • 1,427
9 votes
0 answers
492 views

What was the specific function of the relay which captured Grace Hopper's famous "bug"?

Computer pioneer Grace Hopper often recounted the story of her team finding the first physical computer bug: While she was working on a Mark II Computer at Harvard University in 1947, her associates ...
user avatar
  • 14.2k
9 votes
0 answers
118 views

On the TRS-80 models I and III when is the directory track number written in the third byte of sector zero, and when in the second byte?

Earlier I had found that many but not all TRS-80 Model I and Model III disks begin with the three bytes 00h FEh 11h. This is the beginning of the boot sector where the CPU interprets it as a NOP ...
user avatar
  • 4,380
9 votes
0 answers
537 views

What are all the patches that SetPatch applies to Kickstart?

SetPatch runs as the first command in the Startup-Sequence when Amiga boots up. It applies patches to the code in ROM to fix bugs and also enable features if necessary. For example, I seem to remember ...
user avatar
  • 3,606
9 votes
0 answers
406 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 ...
user avatar
  • 16.4k
9 votes
0 answers
624 views

How many Amiga 3000's were produced?

While revisiting this question: Seeking details relating to Amiga 3000 serial numbers I began to wonder how many actual Amiga 3000's were produced by Commodore. I suspect (like most production ...
user avatar
  • 8,456
8 votes
0 answers
411 views

What did the Big Red Button actually do on the IBM 4341?

Wiktionary explains the origin of the term molly guard: Originally a Plexiglas cover improvised for the Big Red Switch on an IBM 4341 mainframe after a programmer's toddler daughter (named Molly) ...
user avatar
  • 14.2k
8 votes
0 answers
289 views

How is the ‘Coprocessor segment overrun’ exception supposed to be handled?

The Intel 80386 CPU didn't have an on-board x87 FPU (maybe with the exception of some non-Intel clones). It was, however, able to use either a 80287 or 80387 as an external FPU. When the x87 FPU ...
user avatar
  • 1,427
8 votes
0 answers
181 views

Systems that used the Rockwell R65C00/21 or R65C29

The Rockwell R65C00/21 and R65C29 are described in an October 1984 datasheet ("R65C00/21 dual CMOS microcomputer and R65C29 dual CMOS microprocessor," Document no. 29651N64, rev. 2) which is ...
user avatar
  • 1,225
8 votes
0 answers
376 views

Behavior of lesser known illegal M6800 opcodes

The M6800 had a few illegal opcodes, including the (in)famous HCF (Halt and Catch Fire). The following illegal opcodes were revealed in BYTE Magazine, December 1977: $14: NBA $87: STAA immediate $C7: ...
user avatar
  • 1,399
8 votes
0 answers
242 views

A learning gomoku in Lisp

Years ago I played a version of gomoku that was written in Lisp that learned as you played. After a few rounds, it became nearly unbeatable. This was on Unix System III on a small PDP-11. I have ...
user avatar
8 votes
0 answers
211 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. ...
user avatar
8 votes
1 answer
404 views

Why was the Altair numbered "8800" even though the processor was an 8080?

The Altair 8800 was a computer using the Intel 8080 processor. Why the difference in numbers?
user avatar
  • 14.2k
7 votes
0 answers
72 views

Apple II floppy drive, pressure pad cleaning or replacement?

This is related to the following question: Cleaning 5¼" floppy drives Is there a proper way to clean the pressure pad that simply presses against the back side of a single-sided 5.25-inch ...
user avatar
  • 3,491
7 votes
0 answers
221 views

Small format X terminal with EL screen

I remember an ad for a small-format (about as wide as a 60% keyboard) dark-ish grey colored X terminal that had a 12" (?) yellow electroluminescent screen similar to the Grid laptops but higher ...
user avatar
  • 375
7 votes
0 answers
282 views

How can I read from a ferrite memory core today?

I need a little help navigating this ferrite core memory technology. My end goal is to use it in a calculator or something straightforward. I understand the writing process to each core but how is ...
user avatar
7 votes
0 answers
229 views

How did the PSP firmware 5.03 HEN-C exploit work?

On the historical PSP (PlayStation Portable) console on firmware version 5.03 there used to be a thumbnail-based exploit called HEN-C. It worked (under a race condition I presume since it didn't work ...
user avatar
7 votes
0 answers
191 views

How does Amiga HDToolbox calculate size?

I've been toying around with various drive geometries using the classic HDToolbox from 2.x/3.1 on my Amiga. What I've discovered is the total size calculated is always 1 cylinder short of my own ...
user avatar
  • 8,456
7 votes
0 answers
329 views

What are the differences between MS-DOS and DR DOS FASTOPEN?

OS/2 Museum's history of DOS mentions the FASTOPEN.EXE TSR was introduced in DOS 3.3. Its entry on DOS 4.0 adds some implementation details. It reminded me of the DR DOS FASTOPEN=nnnnn directive in ...
user avatar
  • 2,798
7 votes
0 answers
404 views

What is the origin of executable compression?

According to the wikipedia article on the topic, the earliest executable compressor listed is Realia Spacemaker for IBM PC (since 1982, written by Robert B. K. Dewar, SM.COM, signature "MEMORY$&...
user avatar
  • 16.4k
7 votes
0 answers
160 views

Need help checking an ADC0808 / ADC0809 chip in a arcade shooting game

Main Question: How can I check a ADC0808 chip to determine if it needs to be replaced or if my issue is something else? Any advice you can offer is SO appreciated! ADDITIONAL INFO When the arcade is ...
user avatar
  • 71
7 votes
0 answers
267 views

When did Multics begin using '>' as a pathname separator?

As described in this question, Multics used > as the separator between components in pathnames, and < as a parent directory indicator in relative paths. However, an early paper describing the ...
user avatar
  • 12.4k
6 votes
0 answers
231 views

What is this Terminal (or Micro)

I came across this picture, part of this collection, taken by Martin Langer for this collection, possibly in northern Germany (Ostwestfahlen) in 1982/1983 What terminal or micro computer is shown ...
user avatar
  • 173k
6 votes
0 answers
197 views

Atari ST image viewer with unusual zoom

I'm looking for info on an Atari ST (16-color) full-screen image viewer that I once used. When zooming in the edges between colors were smoothly curved (instead of e.g. no smoothing or interpolation ...
user avatar
  • 8,930
6 votes
0 answers
324 views

Looking for an 8-bit microcomputer with a hardware-accelerated database

In some old video on YouTube a few years ago, I noticed a curious computer from the end of the 70s - early 80s. In the rack (half height), typical of minicomputers of those years, there was a 14" ...
user avatar
6 votes
0 answers
342 views

The first micromouse competition in 1977 had 6000 initial entries, what would the majority of them have been (e.g. wall followers)?

The first micromouse competition in 1977, had 6000 initial entries, what would the majority of them have been (e.g. wall followers)? Note - In the link above, first micromouse competition in 1977, it ...
user avatar
  • 137

15 30 50 per page