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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tonyb
Houston, US
★★★★★ 5
Fit as stated
Size: 8.8" x 9.3" x 1.1"
Perfect fit for my 2013 Honda and price was great
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 28, 2025
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Shire23
San Leandro, US
★★★★★ 5
Great Replacement Cabin Air Filters for my 2008 Honda Civic
Size: 2Pcs, Size: 2Pcs
Item Reviewed: CF10134 Cabin Air Filter with Activated Carbon Replacement for CP134, Fit for Honda Accord/Civic/Odyssey/CR-V and Acura MDX/TSX/TLX/RDX/Ridgeline (2 pack) ℹ️ Summary I picked these up because I needed some replacement cabin air filters for my 2008 Honda Civic. These seem like decent quality and they were a perfect fit in my car. For $15 at time of order for two air filters it was a solid deal that I can glad recommend to others. I hate writing short reviews, but there’s not much else to say about these. Here is how I rate items: 5 ⭐️ = Completely exceeds expectations. 4 ⭐️ = Works well with minor concerns. 3 ⭐️ = Does the job, nothing special. 2 ⭐️ = Some things work, but lots of issues. 1 ⭐️ = Didn’t work well, not worth it.
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Reviewed in the United States on September 30, 2025
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TLau
Lake Worth, US
★★★★★ 4
Good fit for Acura MDX
Size: 8.8" x 9.3" x 1.1"
This is an air cabin filter that will fit many cars, and in my case a 2019 MDX. Since this kind of filter is not doing anything critical like keeping dirt out of an engine, I shop around for non-OEM filters for something that strikes a balance between price versus performance. This filter just filters out dust in a car cabin, and when we’re not in our cars, we don’t have the benefit of an air filter when we are walking around outdoors. At a fraction of the price of an Acura filter, this filter seems to strike that balance. The filter media looks sturdy and is embedded with charcoal to help absorb odors. Installation is very straightforward in my MDX, and similar in most cars. There is a compartment door inside the glovebox that first must be removed before changing the filter. Pay attention to the direction flow arrow that shows which way the filter should be installed. Overall I am satisfied with this filter. It is inexpensive, fits perfectly, and seems to do the job just fine. It is definitely worth trying if you are trying to save money.
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Reviewed in the United States on October 12, 2024
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Shop by Interest
Grantham, US
★★★★★ 5
These filters do the job
Size: 2Pcs
Fits great in my '08 Accord LX and my '19 Accord Sport 2.0t. They filter air well and are easy to install like any cabin air filter in a Honda. I am pleased. Good value for the price.
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Reviewed in the United States on October 8, 2025
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Lars A. Morgan
Phoenix, US
★★★★★ 5
Fit my 2014 Odyssey TE
Size: 8.8" x 9.3" x 1.1"
Comes with printed instructions for those who haven't changed it before. Here is the specific use case from my van. On my 2014 TE its easy to access behind the glove box, open to usual full open then just push the left and right sides in to allow the glove box to come fully out. It may pop off of the mounts, don't panic it snaps right back on. Then look for the little rectangular panel with two small levers on either side. on the black plastic under the dash that you can now see and access. Press the levers and pull towards you, doing a bit of a wiggle to get it out. Its tight, but it will come out with having to break it. Don't gorilla hands it, it will break. There is a directional arrow on the filter, which you have to remove from the wrapper before installing. Yes, someone *will* forget that. Reassembly the reverse of removal. Check that video sharing site online if you need visual instructions.
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Reviewed in the United States on September 27, 2024

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