![]() ![]() ![]() The HP 9845 file system is based on different areas on the medium: a single system record, a file directory, an availability table and the area where the file data is stored. The HP 250 had been developed in Fort Collins/Colorado, where also the HP 9845 was born, and adopted many of the concepts of the HP 9845, including the hybrid processor and, of course, the file system format. In fact the 9845 file system was identical to that of the HP 250/260 integrated multi-user computer system. This is similar to the view on modern disk drives with their Logical Block Address (LBA) scheme. The generic view on mass storage is in principle just that of a linear seqence of records, starting with record zero. The basic entity is the record, a 256 byte block of data. ![]() The file structure is almost the same for all peripherals. This concept did fit well into the hardware concept of the HP 9845, which was very generic, too. ![]() This would not only have the advantage of re-usable code, but also simplified data transfer from one media to another and provided a standardized user interface for mass storage operations. With the 9845, HP wanted to create a system where most mass storage routines could be implemented independently from the underlaying hardware and media. For example a standard format for tape drives was created, the so-called SIF (Standard Interchange Format), which was not really portable to other types of media. Before the 9845, HP experimented with mass storage concepts which were more or less media-centric. When designing the 9845, HP developed a new concept they called the "unified mass storage model". Also see the HP-IB Tutorial for more information on the HP-IB. And it can be used to prepare images for the HPDrive program, an HP-IB mass storage emulator.Īlso see another program, the HPDrive utilitiy for emulating vintage hard drives on a PC in the HPDrive Project section. For vintage HP drives it supports all the AMIGO and the CS/80 or SS/80 command sets. It works both with 9845 and LIF file systems, handles hard disk drives as well as tape drives and supports access to non-standard floppies in standard PC floppy disk drives. It can initiate diagnostics on the HP-IB bus, on drives connected via HP-IB bus or on vintage floppy media. It can also restore original media from these images. It can dump sector-by-sector images from HP-IB drives or floppy disks in order to archive the original media content. It can convert files from one file to another, including the conversion of data and program files, so that they get readable and editable on a PC. It is able to list the contents of file systems and to extract files from drives connected via HP-IB, files included in binary images and files from old non-standard HP floppy disks. The HPDir program is much like a swiss pocket knife for vintage HP drives, media and data. Original vintage mass storage peripherals and media shall be controlled, read and written directly from a PC without any other vintage system involved.Binary images of HP 9845 media have to be handled in order to create, duplicate and initialize image files, and to maintain all the files which are stored in the binary image.There are two main reasons for the HPDir program: ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |