This repo is hosting the companions diskettes: disk 1 and disk 2, from the book: PC Assembly language Step by Step, by Alex Hoffmann, from Abacus software, 1990. You can read the book here, thanks to our friends from Internet Archive. The book is part of “Developer's series”, a series made for teaching programming languages. The great differential of Abacus is that, from some point in time, the books were supplied with a media (floppy disk and later CD-ROMs), with the code files and sometimes some extra software needed or referenced in the book. This is from a time before the internet era, and this kind of approach was not that common when they started.

The media was generally inside the counter cover with proper protection, a small hard plastic bag glued to it, where the media(s) was(were) inserted. In the case of the 5 1/4' floppy it also came in the standard paper cover, later they also supplied 3 1/2' floppy, as CD-ROMs too. The disks came not just with source code files, but many times, with some programs that were the subject of the book or have extra features that added value to learning. In the case of the book in question, the author uses a program call SIM88 to make all the exercises inside the book; so you have to have the software to complete the exercises, and in my case, I lost disk 1 which had this program. I lost because it get totally corrupted by mold, surprisingly the same thing didn't happen to disk 2.

It took me years and a lot of work to find this program on-line somewhere, please see my comment on the book page on Internet Archive. Also , I had some lucky here. First I tried to contact the author, but had no success, the name is too generic and we have dozen of Alex Hoffmann, emailed some but no answer. Tried to get in touch with Abacus software, but they closed in 2012. Someone bought their archive later but just for continue with flight simulator things , all the previous state was gone. That's a shame because is a huge amount of knowledge lost. I may write about it someday. I also got in contact with some universities around the globe which had the book on their libraries ( Yes, I did that), and just one from the US, returned me and real checked the book at the bookshelves (almost got it!), but no disk inside. I can't remember right now what university was, but they were so kind. Only in America to have such respect! I also tried to get in touch with the book editors, just found one of them, Mr. Scott Slaughter, but he didn't reply me. I also contacted many used books sellers which had the book to see if one copy had the disks, but I got no success too. You can't say I haven't tried to get those disks from the people who made this book. Probably someone had already passed by a similar situation with other titles.

Anyway, I uploaded here the same software programs of the disks, I did not want to infringe any copyright, just make a fair usage, but if for any reason someone thinks otherwise, please contact me. The software programs are not open source and should not be used for any other purpose than learning, I dunno they will have any other purpose nowadays, but who knows? You'll need an MS-DOS machine (virtual or bare metal). You can try with DosBox or DosEmu, or even with vdos (very good dos emulator to run old DOS software on Windows); but I didn't test completely with emulators, as we're talking about 8088 Assembly, and none of them guarantees 100% of compatibility, please be aware you may find some problems. So, be careful. You may lose your (other) work on the machine which is running the emulation. SIM88 looks to be made to emulate the 8088 CPU, to teach how the 8088 microprocessor works, hell of work, simple and very efficacy, but not to program directly in Assembly language. For that the author made available evaluation versions of an assembler (A86) and a debugger (D86) made by Eric Isaacson in disk2, which by the way, is still on duty (impressive!). I talked to him by email, and he didn't remember of the deal with Abacus or the author, or the emulator, but his programs are still available for purchase at https://eji.com/a86/. I also would like to thank Ross McGowan which has a great playlist about CPU design (and some courses on Udemy), which left a comment on the book's Amazon page, allowing me to find him from there; to discover he also had issues with disk 1, then bought another used copy, and had the same problems. Later, we kept in contact to advise each other of who would find the disk first. That's it. Have a nice learning time, if there is still anybody out there who is interested in learning 8088 Assembler.