To build a virtual file system that permet to stock binaries in the memory and access them by using an application, that can reads files and modify them in the future.
0xFFFF ---------
| |
|ROM 16k|
| |
0xC000 ---------
| |
| EMPTY | For new devices
| |
0xA000 ---------
| I/O |
0x8000 ---------
| SYS |
0x7C00 |+++++++|
| |
| |
|RAM 32K|
| |
| |
0x0000 ---------
In my disopsition I have only 0x0000-0x7C00 =>
(+
(* 7 (expt 16 3))
(* 12 (expt 16 2))
(* 0 (expt 16 1))
(* 0 (expt 16 0))
)
; 31744So, I have only 31744 bytes for all, for files storage. In ROM I will have my application that will create file system and manage this.
- A accum (8Bits)
- B accum (8Bits)
- D accum (16Bits)
- X index (16Bits)
- Y index (16Bits)
- DP page register (8Bits)
- CC state (8Bits)
- U stack pointer user
- S stack pointer System
It should store in ram some modifiables files. So I need to know where to find thats files.
| # | catalog name | start loc | size |
|---|---|---|---|
| 1 | 11 byte | 2 byte | 3 byte |
| . | … | .. | .. |
| 4 |
16 bytes for each element of catalog.
Catalog position + #112 = last element of catalog.
Name of file shouldn’t containe any spaces. Each file is txt, so you don’t need to add it. Moreower you are limited in length by 10 bytes (10 characters).
Size of each file is limited by 4096 bytes. End of the file should be indicated by three zeros.
$00 $00 $00