Unanswered Questions
359 questions with no upvoted or accepted answers
23
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0
answers
439
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What bugs did initial version of the Z8000 have?
Quite a few sources around the Internet talk about how bugs were present in initial versions of the Zilog Z8000 due to its non-microcoded design (such as its entry in Great Microprocessors of the Past ...
- 1,491
21
votes
0
answers
688
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Is an X Window System older than release 10 available online?
I'm looking for any copy of the X Window System older than release 10.
The oldest on x.org is X10R3.
Bob Scheifler doesn't have anything.
Jim Gettys may have something, but has yet to retrieve it ...
- 3,231
20
votes
0
answers
492
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Historical use of the SID chip outside Commodore products
The SID chip (originally the MOS Technology 6581) was the sound chip used in the original Commodore 64, and is widely credited with helping make that machine one of the best-selling home computers of ...
- 5,693
20
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0
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1k
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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 ...
16
votes
0
answers
1k
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Original instruction set for the first ARM processor
I'm studying ISAs and would really like to see the very first ISA that Sophie Wilson chose/put together when designing the very first ARM CPU while at Acorn Computers around 1983 or so.
From what I ...
- 41.5k
16
votes
0
answers
970
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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 ...
CommunityBot
- 1
16
votes
0
answers
696
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Is there a simple BASIC program that demonstrates SID6581 distortion on C64?
Many songs on Commodore 64 use a SID 6581 design "flaw", distortion, as an effect. I tried experimenting with the filter and resonance registers, but was unable to reproduce the sound.
What ...
- 113
15
votes
0
answers
371
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Did CompuServe ever define and document any GIF extension blocks?
The GIF file format was introduced by CompuServe in 1987 (version 87a) with an updated version released in 1989 (version 89a). Each version has an official specification:
GIF™ Graphics Interchange ...
- 8,552
14
votes
0
answers
377
views
What do “Cert DX2” strings embedded within some Windows drivers signify?
Executable formats used in Windows – PE, LE and NE – are extended from MS-DOS’s MZ executable format. This means that Windows binaries (including DLLs) can potentially be run as MS-DOS executables, ...
- 28.6k
14
votes
0
answers
535
views
When was the asterisk first used for "unsaved changes" and why?
The asterisk itself has been around as a symbol since literally (pun intended) before the earliest writing systems. Among its many uses, in some user interfaces it denotes unsaved changes to a file or ...
- 241
14
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0
answers
611
views
Is it possible to trap 387 FPU opcodes on a 287 connected to a 386?
The 8087 and 287 FPUs were designed before the IEEE 754 standard was released. Because of this, they contain some instructions which are not compliant with it. When the 387 was released in 1987, it ...
- 28.6k
14
votes
0
answers
288
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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 ...
- 141
13
votes
0
answers
517
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.
- 22.8k
12
votes
0
answers
353
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What was and where can I find OS-1 for the Z80?
On page 269 of the June 1980 issue of BYTE there is an advertisement from Electrolabs (in Stamford, CT) for an operating system called OS-1, a "new Unix-like operating system for Z-80."
Did ...
- 29.7k
12
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0
answers
326
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How did Windows NT for PowerPC initialize the `r2` register when loading an EXE file?
I'm poking around an old Windows NT PowerPC executable and trying to understand how the r2 register is initialized on startup. Looking at the entry point of the program, I see the following code:
mflr ...
- 2,511