SKU: 90829067784

DOS 4.1 Disk Operating System Second Edition

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Description

DOS 4.1 Disk Operating System Second EditionDOS 4. 1 is a newly imagined Disk Operating System for the Apple ][ computer, initially released in 2018. When the DOS 4. 1 Manual was published, DOS 4. 1 was not yet finished until Build 46 was completed in 2019. Designed and programmed by Walland Philip Vrbancic, Jr., a professional programmer and Electrical Engineer since 1983, DOS 4. 1 contains the power and the flexibility he always thought DOS should have while remaining essentially compatible

DOS 4.1 is a newly imagined Disk Operating System for the Apple ][ computer, initially released in 2018. When the DOS 4.1 Manual was published, DOS 4.1 was not yet finished until Build 46 was completed in 2019. Designed and programmed by Walland Philip Vrbancic, Jr., a professional programmer and Electrical Engineer since 1983, DOS 4.1 contains the power and the flexibility he always thought DOS should have while remaining essentially compatible with DOS 3.3. DOS 4.1 Disk Operating System Second Edition describes all of the features that comprise DOS 4.1L and DOS 4.1H, including those features introduced by Build 46, using redesigned Tables, Figures, Schematic Diagrams, and example Assembly Language Routines. The following list are some of the features that have been engineered into the second edition of the DOS 4.1 Disk Operating System. DOS 4.1H boots directly into Language Card memory and sets HIMEM to 0xBE00. All five of its file buffers are fully contained in Language Card memory. DOS 4.1 supports the full 65C02 instruction set and it can now be used in both the Lisa and the Big Mac assemblers. Sourceror and Big Mac both support all SWEET16 opcodes. The ROM image described in this book supports the 65C02, SWEET16, and GARBAGE based on BongersÕ algorithm. DOS 4.1 supports most Clock Cards which play an integral role in Volume and File timestamps. Volumes may be titled, numbered, and initialized to boot or to store files and data exclusively. Even track 0x00 is used to store files and data. Files are loaded into memory and saved using a page-accelerated algorithm. DOS 4.1 supports Applesoft CHAIN, File DIFF, File GREP, File LIST, File Undelete, Sector Display, Syntactical HELP (only in DOS 4.1H), and full lowercase command and argument input. DOS 4.1 has an expanded File Manager with additional Opcodes, and the Boot and Volume INIT functions utilize the same BOOTCFG Table. The Volume Catalog may use a minimum of a single sector and the CATALOG output may be terminated by pressing the ESC key at any time. DOS 4.1 uses the B keyword to implement the ÒFile Delete/File SaveÓ strategy for disk space conservation. DOS 4.1 can read DOS 3.3 Volumes, files, and data. DOS 4.1 can easily initialize Volumes with up to 48 tracks having either 16 or 32 sectors per track. All the source code and all the schematics can be requested through www.applecored.net.

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SKU: 90829067784

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DB
Bozeman, US
★★★★★ 5
Cute toothbrush!
This toothbrush has an excellent design. The little dinosaur is cute, and the spaceship bottom is just the cherry on top. I do wish the bottom was a charger too, but the battery life is supposedly 75 days so it should not be on the charger much anyways. It looks pretty good, and the lower sonic function seems soft enough of a vibration that my 5 year old should be fine with it (he has his first loose tooth right now, so was a bit concerned). I think it cleans and brushes well. The documentation states these are dupont brush heads, and it comes with 4 of them. As a side note, there is one that will be out of the bag. Grab that one for the initial head, not the ones in the bag like I did. I think its fairly durable as well. It didn't feel too heavy or too light, or more importantly too flimsy. I like it has some different modes, I didn't honestly notice until I went back to look at the documentation that this was possible. The big thing to keep in mind here is does your toddler deal well with vibration. My 5 year old seems cool with it so far, though you should still supervise them so they don't brush too hard.
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Reviewed in the United States on September 2, 2025
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Verified Purchase
Jorge cuadrado
Phoenix, US
★★★★★ 4
Buen Producto
Buen productos
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Reviewed in the United States on September 25, 2025
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BAJUNGADUSTIN
Grantham, US
★★★★★ 4
Base isnt a charger, But otherwise its decent.
The overall quality of this product is high. It worked and funcioned as expected. My toddler hated it. He couldnt deal with the vibration even on the toddler steeing. It has 2 settings for different age ranges but you have to go through them every time you turn it on. This would have been better as a selector switch somewhere else that remained in place. The base is NOT A CHARGER. that was very dissapointing. Not only is the base NOT a charger, you cant even plug the toothbrush in and then let it sit in the charger. The should have just made the base...the charger. Plug that in and leave it and that way the tooth brush stays charged all the time. Overall other than the base being a dissapointment this isnt a terrible toothbrush. If your child is ok with the vibration they will probably love this.
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Reviewed in the United States on August 11, 2025
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Derrick
Dallas, US
★★★★★ 5
Works well has plenty of pressure.
It is a great device, a bit awkward to use over a bowl sink, but with some minor adjustment of the nozzle, it works well. It appears to be as effective as most water picks and I like not having to fool with a hose, that can break.
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Reviewed in the United States on September 2, 2024
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J. A.
Charlottesville, US
★★★★★ 4
Needed replacement, 2nd one works OK
The first one I received had a broken latching mechanism. Not a shipping issue, as the box was fine, it just wouldn't latch the attachments because the mechanism wouldn't come all the way out. After getting a replacement the 2nd one worked better. It has 3 settings for soft, normal, and pulse. For me, the normal put out the best force for clearing out bits. After washing with it for about 30 seconds though I still don't feel it cleans we well as real floss, or even a waterpik, but it does help after brushing. I will add it to my routine as it does help flush out some things, but it won't be replacing my flossing. It is sort of portable, in that can be packed away and holds a charge, but it's still pretty large and takes up a good amount of space in a toiletry bag. It's not bad, but not really outstanding either.
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Reviewed in the United States on May 13, 2024

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