hippietrail
  • Member for 5 years, 3 months
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1 answers
18 votes
5k views
Could Pac-Man be replicated perfectly on the ZX Spectrum?
66 votes

Both the Sinclair ZX Spectrum and the Pac-Man arcade machine used the Zilog Z 80 CPU. Pac-Man's display was slightly larger and vertical at 224×288 while the Speccy's was horizontal at 256×192. The ...

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3 answers
19 votes
1k views
Which (micro) computers were dominant in Australia and New Zealand in the 1980s?
10 votes

I started programming microcomputers in 1979 as an 11-year-old in Melbourne, Australia. This is how it is in my memory, which I am sure is only a rough approximation of reality. I never saw anything ...

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2 answers
7 votes
1k views
Could Tandy TRS-80 Color Computers boot from disk at all?
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10 votes

Thanks to RichF's answer I looked for information specifically on booting OS-9 and found that you definitely did have to manually launch even an alternative operating system. From OS-9 Level Two ...

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3 answers
6 votes
2k views
What are D64, T64, D71 and D81 files?
8 votes

Since I've been writing code to interact with various systems' disk image formats over the past few weeks I'd like to add a little more information that's not in the current answers. Disk images and ...

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1 answers
4 votes
323 views
Does anybody have the PDP-11 CAPS-11 source code?
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3 votes

A guy named Lou Ernst on the Usenet group alt.sys.pdp11 mentioned that he had it with sources back in 2011: Last night we finally got CAPS-11 running on our 11/04 with TA11/ TU60. Jack R. was given a ...

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1 answers
3 votes
192 views
Do TRS-80 Model I and Model III load and execute /CMD files using specific memory addresses?
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3 votes

/CMD files are a series of tagged records. Some record types have meaning only for certain features of some of the TRS-80 DOSes. Only two seem important for loading and executing them. byte: ...

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3 answers
16 votes
2k views
Where did the the term "chrome," referring to onscreen decorations, originate?
2 votes

(Extending my previous comments into an answer...) I'm not sure about "most people". I'm Gen X and I'd expect most people from my generation and before think of "chrome" as a ...

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1 answers
5 votes
94 views
Length of leader block in Coco and Dragon cassette tape header and .cas tape image file format
2 votes

I've made a couple of discoveries after a night's sleep. The CoCo still reads the leader length from a RAM address, but its address is two bytes higher in memory than in the Dragon 32: 0199 ** THESE ...

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1 answers
2 votes
125 views
Which Apple II emulators were the first ones each to use the .do and .po "dsk" floppy disk image file formats?
1 votes

This answer is still a work in progress... A Unix emulator named "Apple //e Emulator" by Randy Frank (aka "apple2e" or just "ap2e" in filenames) goes right back to 1990. ...

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1 answers
3 votes
241 views
What is the process for TRS-80 Model I & III to boot from disk?
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1 votes

After Googling this for an hour or two and not finding much, I have found something solid just minutes after posting my question! From page 40 of TRS8BIT volume 09 issue 02 from June 2015 there is an ...

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1 answers
2 votes
147 views
Are there open source Java libraries for reading DSK and EDSK disk image files as used by Amstrad and Spectrum +3 emulators?
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1 votes

It seems there is. There is an open source C library by John Elliot for working with a selection of disks and disk image formats called LibDsk, active as of August 2019. Among the supported formats ...

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2 answers
3 votes
679 views
What file formats were used for binary executable files on later Sinclair ZX Spectrums?
1 votes

TR-DOS Files themselves have no header at all. Metadata is stored in the directory section of the disk, along with the filename. The metadata has a type field, which is also the file extension. ...

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2 answers
4 votes
279 views
How did the Spectrum clones with TR-DOS and paged memory load and run code files from disk?
1 votes

This is only a partial answer so far. TR-DOS was first part of the Beta 128 disk interface, which was cloned along with the Spectrum itself in Russia and Eastern Europe. According to this Beta 128 ...

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22 answers
31 votes
8k views
Was self-modifying code possible using BASIC?
1 votes

On the Sinclair ZX Spectrum, if you know where the BASIC program resides in memory, and you know the format of the tokenized program, you can modify the code by POKEing into this memory. And you can ...

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16 answers
37 votes
10k views
Did anyone ever use the extra set of registers on the Z80?
1 votes

I used them all the time. I starting programming Z80 machine code when I was 14 or 15 on a Sinclair ZX Spectrum after being briefly introduced to it on a friend's TRS-80 model 1 and 3. On the Speccy ...

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1 answers
0 votes
314 views
Do any of the open source Sinclair ZX Spectrum emulators support both TR-DOS and 3DOS?
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0 votes

Yes! Fuse, which is mainly for Unix also builds and runs on Windows. It supports more machines than Spectaculator, including the +3, the Scorpion, and the Pentagon. So it supports both +3DOS and TR-...

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