Method and system for file system management using a flash-erasable, programmable, read-only memory
Microsoft Corp.This patent was asserted by Microsoft Corp. against TomTom
Last updated: over 3 years ago
Summary / Description
| Summary / Description | The Cambridge Z88 (sometimes referred to as the Cambridge Computer Z88, or Sinclair Z88), developed by Sir Clive Sinclair, was a forerunner to today's netbook computers. It had no hard drive, but used removable EPROM modules for its file system storage. From the user's perspective these modules behaved, via the operating system, like a hard drive or PC file system. The Z88 was available to the public in 1987. |
Basic Information
| Type of Prior Art | Source Code |
| Name/Title | The "OZ" operating system |
| Publication Date | February 17, 1987 |
| Author | Cambridge Computer Ltd |
| URL | http://en.wikipedia.org/wiki/Si... |
| System Type | Operating System |
| Printed Materials (Documentation, Manual, Training Guide, Literature, et cetera) | No |
| Online Source Code Repository | No |
| Online project documentation | No |
| Storage Media (Floppy disk, CD-ROM, Tape, et cetera) | Yes |
| Other | No |
| How to Locate the Evidence (e.g. Location of the System Documentation -- Product Manual, User Guide, or Training Guide) | Operating System ROM |
| URL for Software Repository | |
| URL for Product Description | |
| Licensing Model | Proprietary or Closed Source |
| Programming Language | Unknown, possibly Z80 assembler |
Notes / To Do
| Notes | A separate eraser (ultra-violet) was used to completely wipe an EPROM card. I don't recall whether it was possible to delete an individual file from EPROM. I still have a couple of these systems in my attic though, so I could check that out. It's diff |
Excerpt
...It had three memory card slots, which accommodated proprietary RAM, ROM or EPROM cards, the third slot being equipped with a built-in EPROM programmer. Card capacities ranged from 32 KiB to 1 MiB. Most users used one or two 128 KiB cards...
...Since 1998, a 1 MiB Flash memory card is available which provides convenient non-volatile storage. Once written to the card, files are safe and not reliant on a power supply. Unlike traditional EPROM cards (erased with an external ultraviolet light), this one can be electrically erased in the computer's slot. The first generation of card only worked in slot 3 where a 12V signal (Vpp) is available. The later generation is based on AMD chips and runs with 5V for erasure. It is possible to read, write and erase flash cards in the three slots and the internal one...
Relevance
Claims
Memory manager with file allocation table
A manager for a computer memory comprising:
a block allocation routine, the memory divided into blocks of memory locations, each block having an allocation table and a data region divided into data areas, each allocation table having entries corresponding to region data areas, the block allocation routine for selecting a block in which to store data;
a data area allocation routine for selecting a data area within the data region for the selected block in which to store data, for selecting an allocation table entry to correspond to the selected data area, and for setting the selected allocation table entry to correspond to the selected data area and to an allocated state; and
a storage routine for storing data in the selected data area.
Relevance
It's difficult to know what the relevance is for sure, as this functionality would be encoded in the operating system ROM. There might have been relevant UK patents held by Sinclair Research or Cambridge Computer. The same may apply to other claims, which I have left unselected, because I don't know for certain.
It's difficult to know what the relevance is for sure, as this functionality would be encoded in the operating system ROM. There might have been relevant UK patents held by Sinclair Research or Cambridge Computer. The same may apply to other claims, which I have left unselected, because I don't know for certain.
Claim Chart
All
Block-erasable, programmable ROM
The method of Claim 6 or 7 wherein the computer memory device is a block-erasable, programmable, read-only memory.
Relevance
The original EPROM cards were not erasable in the computer, but later flash-erasable cards became available and could be erased in situ. It is not clear whether this flash-erase function was part of the original Z88 specification, but seems likely.
The original EPROM cards were not erasable in the computer, but later flash-erasable cards became available and could be erased in situ. It is not clear whether this flash-erase function was part of the original Z88 specification, but seems likely.
Claim Chart
Some
