33 votes

Late 1970s and 6502 chip facilities for operating systems

The simple answer is that early operating systems for the systems you mention did not provide those features. Apple DOS, for example, makes no use of interrupts, and has no concept of processes or ...
RETRAC's user avatar
  • 13.6k
29 votes
Accepted

Late 1970s and 6502 chip facilities for operating systems

For "home" computer systems such as the Apple II, the "operating system" wasn't anything like a modern one with processes and device drivers and so on; by the standards of modern ...
cjs's user avatar
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27 votes
Accepted

Could you manually eject a floppy quick enough to prevent data loss?

I did that all the time on the Apple II. The reason it worked was that some time was needed for the motor to spin up to the correct speed, and that the Disk II didn't really have an "eject" mechanism, ...
dirkt's user avatar
  • 26.1k
18 votes

Late 1970s and 6502 chip facilities for operating systems

We talk about the late 1970s and mainstream 6502 machines, right? It wasn't so much that programs run under OS control as that OS was a support function to Programs. More like what we would today ...
Raffzahn's user avatar
  • 213k
17 votes

Apple II: DOS 3.3 Virus?

I am one of the two authors of Killer DOS. If you know the final lock screen when your disk was corrupted, we took credit as "The Master" and "The Wizard". I was the DOS Master. We were high school ...
Apple II DOS Master's user avatar
17 votes

Was Apple DOS 3.3 created because of the Apple III?

No, conversion to 16-sector format (and the necessary change from DOS 3.2 to DOS 3.3) was a consequence of Steven Wozniak realizing that he could get more capacity by tweaking the Apple II floppy ...
dirkt's user avatar
  • 26.1k
16 votes

Could you manually eject a floppy quick enough to prevent data loss?

Theoretically, yes. The disk needs time to spin up to speed before reading or writing can occur. While it varies between platforms and drives, it's at least a couple hundred milliseconds. That's ...
RETRAC's user avatar
  • 13.6k
16 votes
Accepted

Was Apple DOS 3.3 created because of the Apple III?

TL;DR: No, not really. It was even more twisted. 16 sector was done for the Pascal System for the Apple II, independently and before the Apple III got it, but didn't get rolled out for DOS until after ...
Raffzahn's user avatar
  • 213k
16 votes
Accepted

How many versions of DOS were there for the Apple II and what were the differences?

There was no public release of DOS 1 or 2. DOS 3.1 was actually the first release to the public. It had a pretty significant bug in its MASTER CREATE program, and so the patched version DOS 3.2 was ...
knghtbrd's user avatar
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16 votes
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What exactly was the intent and implementation of Apple DOS 3.3's volume concept?

I'm curious what the intent and actual implementation of the feature was. It's meant to identify diskettes. Much like volume names on DOS or similar on other OS. In fact, Apple DOS was ahead, as ...
Raffzahn's user avatar
  • 213k
13 votes
Accepted

Apple II: DOS 3.3 Virus?

What you're looking for is called Killer DOS, which behaved exactly like the Unnamed First Virus described on the Apple II History Viruses page. Killer DOS may have been the second version described ...
Blrfl's user avatar
  • 643
13 votes

Late 1970s and 6502 chip facilities for operating systems

The typical circa-1980 8-bit CPU provided almost no support for modern operating system features. It was often possible to add such support using external logic, but very few machines actually did so ...
Chromatix's user avatar
  • 16.7k
10 votes

Late 1970s and 6502 chip facilities for operating systems

Contemporary operating systems for the 6502 did not have those features. But not because they couldn't. It just wasn't considered necessary or desirable. Provide automatic switching between ...
Bruce Abbott's user avatar
  • 6,635
10 votes

Apple II: What type of partition tables were used?

ProDOS provides a common device driver API for storage systems, but does not specify a partition table format. Rather, the SCSI (or other) HD interface card has firmware to map partitions to ProDOS ...
Brian H's user avatar
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9 votes
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Was the ProDOS beep part of the kernel or just a commonly duplicated piece of code?

It is a programming convention (i.e. copied code), not part of ProDOS. ProDOS 8 Technical Reference Manual 5.4 Programming Conventions The standard Apple II "Air-raid" bell has been ...
Joshua Bell's user avatar
8 votes

Apple II / ProDOS: Run binary games without BASIC.SYSTEM?

First off, the direct answer to your question is "Yes", you can run some DOS 3.3 binary games without loading ProDOS BASIC.SYSTEM. However, it isn't quite as simple as that. Second point is that it ...
bjb's user avatar
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8 votes
Accepted

Apple II: ProDOS partitions on floppy disks?

ProDOS supports up to 2 storage device volumes per slot, but does not support partitioning within those volumes. It is a function of the firmware provided with the storage device controller (i.e. SCSI ...
Brian H's user avatar
  • 60.1k
8 votes
Accepted

How to change what program Apple ProDOS 'starts' when booting

Sorting the root directory to put the desired .SYSTEM program first will fix the issue. You can sort a directory on a ProDOS disk with the ProSel-8 disk utilities or Copy II+. You can also just ...
fadden's user avatar
  • 8,775
7 votes

Why did Apple remove booting from external drives in later IIc ROM versions?

Whilst this is not a definitive answer, by looking at Apple IIc ROM Version1, which more fully lists the features of each ROM version, it seems that the disk support was actually improved, whilst, ...
Greenonline's user avatar
  • 3,349
7 votes
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How could a 16-sector PROM Apple II access a 13-sector disk?

Does it bypass the 16-sector PROMs? Like MUFFIN it got it's own RWTS. How exactly does it work and why does it work on the 16-sector PROM upgraded interface? Because DOS 3.2 also got it's own ...
Raffzahn's user avatar
  • 213k
6 votes
Accepted

6502 Assembly on Apple IIe: GETLN fails with 'syntax error' under ProDOS

There are two basic approaches: Disable the I/O hooks. This removes the operating system from the equation. Write your own line input routine, using the keyboard I/O addresses ($c000 / $c010). ...
fadden's user avatar
  • 8,775
6 votes

What is the VTOC format for an AppleDOS disk with more than 50 tracks?

Summary of comments, plus analysis of "appleii640.img.gz" from the github issue page... This is an 80-track, 16-sector disk. The interpretation of the sector in-use map in the DOS VTOC was ...
fadden's user avatar
  • 8,775
5 votes

Apple II / ProDOS: Run binary games without BASIC.SYSTEM?

The correct answer is, of course, "It depends". ; - ) If the game loads lower than $800 or is multiple files or otherwise tries to use DOS, work is needed. Otherwise use Bitsy Bye and MiniBas in ...
Nick Westgate's user avatar
5 votes
Accepted

Converting Apple II ProDOS blocks to DOS tracks and sectors

DOS-ordered images were created by DOS programs that started reading from track 0 sector 0, continued to sector 15, moved to track 1 sector 0, and so on until the end of the disk. They are in DOS ...
fadden's user avatar
  • 8,775
4 votes

Was Apple DOS 3.3 created because of the Apple III?

Sorry, but the first post is incorrect. Second poster is correct, along with the Disk II controller update. P5 and P6 are the ROMS that were replaced, but otherwise no difference. One is a state ...
Andy's user avatar
  • 49
4 votes
Accepted

How to transfer file from one disk to another in Apple //e (Applewin)

You should download and use CiderPress which is a Swiss Army Knife tool for Apple disk images - It understands and supports the UCSD Pascal file system format and should be able to transfer a file ...
tofro's user avatar
  • 33k
4 votes

Where did the "LEVI" file selector/runner for the Apple II DOS 3.3 come from?

I did some looking around on the internet archive, browsing through a few collections, and I ran across this variant: Rhode Island Apple Group Volume 14 - Integer Basic Games The disk contains a ...
Geo...'s user avatar
  • 9,795
4 votes
Accepted

Where did the "LEVI" file selector/runner for the Apple II DOS 3.3 come from?

The program appears as "HELLO AUTO SELECT" in various public domain software collections that seem to derive from 1981 or earlier. This name appears in The Public Domain Exchange disk 166: "Hello and ...
Nick Westgate's user avatar
4 votes

6502 Assembly on Apple IIe: GETLN fails with 'syntax error' under ProDOS

Some aspects of the Apple II's I/O system are pretty clever. Others, not so much. IMHO, the worst aspect is the way I/O cards use one entry point for everything, meaning that it's not possible to ...
supercat's user avatar
  • 34.7k
4 votes

How to change what program Apple ProDOS 'starts' when booting

I would be astounded if the answer is to "delete everything and add files in the correct order" Jup, that's 'a' solution :)) ProDOS only expects a single SYSTEM to exist on the boot volume. ...
Raffzahn's user avatar
  • 213k

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