SKU: 90153596201

DOS 4.5 File and Volume Disk Management System

Sale price$62.55 Regular price$69.50
Save 10%

Shipping Estimate
USA
  • USA
  • CAN

Ships within 48 hours · Estimated delivery Jul 13 - Jul 18

Promo Codes Available:

For Your Every Summer RSVP, with Code: SUMMER15

Description

DOS 4.5 File and Volume Disk Management SystemThis publication describes the process and the products that Walland Philip Vrbancic, Jr., an Electrical Engineer, an Aerospace Senior Systems Engineer, and a Professional Programmer since 1983, created when he designed and programmed another enhanced Disk Operating System (DOS) for his Apple ][+ and for his Apple e in order to manage Apple ][ Files and Volumes. Wherever he is able, Mr. Vrbancic has included source code samples, schematic diagrams,

This publication describes the process and the products that Walland Philip Vrbancic, Jr., an Electrical Engineer, an Aerospace Senior Systems Engineer, and a Professional Programmer since 1983, created when he designed and programmed another enhanced Disk Operating System (DOS) for his Apple ][+ and for his Apple //e in order to manage Apple ][ Files and Volumes. Wherever he is able, Mr. Vrbancic has included source code samples, schematic diagrams, equations, figures, tables, and representative screen shots to help explain what he has created and the reasons why he did so. As in his previous Apple ][ DOS publications, this has been another incredible journey for him. With DOS 4.5 in particular, he has again re-imagined that time when he mostly lived, breathed, and worked on Apple ][ hardware and software development continuously for a good period of his life many, many years ago. The list of the incredible and powerful features that Mr. Vrbancic has engineered into his new DOS 4.5 File and Volume Disk Management System is staggering.

DOS 4.5L boots directly into Main memory and sets HIMEM to 0x9600 whereas DOS 4.5H boots directly into Language Card memory and sets HIMEM to 0xBE00. Unlike the file buffers in DOS 4.5L, all five file buffers in DOS 4.5H are always available and they are fully contained in Language Card memory.

Mr. Vrbancic has completed the full integration of the Lisa and the Big Mac assemblers into Auxiliary Memory and they both utilize DOS 4.5 File and Volume resources. Also, he has added additional logic to both assemblers so that they both now support the complete 65C02 instruction set. He has fully integrated both Sourceror and Big Mac and they both now support all SWEET16 opcodes. His newest C0:FF Apple //e ROM image is totally compatible with DOS 4.5 and this ROM image now fully supports the 65C02 processor, the SWEET16 metaprocessor, and his phenomenal GARBAGE routine which is based on BongersÕ algorithm. His ROM image also includes a new HLIN routine which draws perfect HIRES line graphics for his celebrated ICON Maker tool that, when paired with his HIRES CHAR Editor and LENGTH tools, create stunning graphic presentations like those used in his Binary File Installation (BFI) software program.

All the utilities, tools, schematics, Excel files, and Edraw files that Mr. Vrbancic utilized as his knowledge-base resources for the development of DOS 4.5 and for this publication can be requested through www.applecored.net.

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 90153596201

Discover Niche Categories That Outsell

Top-Converting Item to Boost Your Average Order

4.1 ★★★★★
Based on 2000 reviews
Sort
Highest Rating
Newest First
Oldest First
Product Reviews
A
Verified Purchase
Al
Lexington, US
★★★★★ 5
Clear, Practical Guide for Entry-Level to Intermediate Multifamily Underwriting
Format: Kindle
As someone learning multifamily underwriting from the ground up, this book was incredibly helpful. It breaks down complex underwriting concepts into a logical, step-by-step process that actually mirrors how deals are analyzed in the real world. What I appreciated most is that the author doesn’t just show formulas — he explains why assumptions matter, where risk hides, and how underwriting decisions affect outcomes. The sections on operating expenses, stabilization, financing, and sponsor economics were especially valuable and gave me a much clearer framework for analyzing multifamily properties with confidence. This book feels less like theory and more like a practical guide you can follow alongside a real underwriting model. I’d highly recommend it to anyone getting started in multifamily underwriting or looking to tighten up their analysis process.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on December 20, 2025
D
Verified Purchase
Derick am owe I
West Palm Beach, US
★★★★★ 5
Underwriting Multifamily
Format: Kindle
This book deserve a five star rating. It uses practical examples easy to follow. This well written book easy to understand. I recommend this book to any real estate investor.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on December 20, 2024
N
Verified Purchase
Nathan Roberts
Dallas, US
★★★★★ 5
Must Have Book for Investors or Sponsors/GPs wanting to Invest in Multifamily Properties!
Format: Paperback
If you understand the math and numbers associated with investing in real estate, this book will help you underwrite any multifamily property. Not only does Robert's book discuss how to gather the information needed for underwriting, he goes into detail on how sponsors can manipulate the numbers. This is a great book for knowledge on the pros and cons of varied partnership structures and how each can create an alignment of interest between limited partners (LPs) and general partners (GPs). Overall, this is a great easy read book.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on September 13, 2020
M
Verified Purchase
MF Student
Chelsea, US
★★★★★ 4
Basic knowledge of underwriting is necessary to understand.
Format: Paperback
This is a great guide for underwriting multifamily deals for someone with some basic to moderate knowledge of underwriting. I am a new student to this field and have to stop and google some of the acronyms. For a future version, I think adding an extra page for the acronyms used, definition and equation would be helpful. I think that the font could be larger and darker. Adding mathematical formulas in the book would provide visualization as well. Rob can also provide a sample OM for the reader to use with his underwriting model and compare to his completed one. Again, I am a newbie so my review may change as I gain knowledge in this area. I enjoyed listening to Rob on Youtube/Podcast and hope to learn more from him.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on July 27, 2020
K
Verified Purchase
K. Okumura
Waukegan, US
★★★★★ 5
Easy to understand and well organized
Format: Paperback
Author makes complex concepts feel approachable and easy to comprehend. The content is sufficient to be an introductory course
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on October 22, 2025

recommand products