FRAM71B
User’s Manual
FRAM71B 1.00
- 12 -
©Hans Brueggemann, 2016
9 Memory
Configuration
The total memory space in FRAM71B is 16 x 32 KB = 512 KByte, where 32 KByte in F_Block 2
is unused, because it overlaps with HP-71B RAM (except for the configuration area). Hence,
the total usable FRAM space is 480 KByte, organized in 15 F_Blocks:
FRAM Address
Purpose
F_Block #
Start
End
HC = Hard Configured
SC = Soft Configured
0
0x00000
0xFFFFF
SYSRAM / RAM / ROM
1
0x10000
0x1FFFF
SYSRAM / RAM / ROM
2
*)
0x20000
0x2BFFF
unused
2
*)
0x2C000
0x2C01F
Config Area For FRAM allocation
2
*)
0x2C020
0x2FFFF
Unused
3
0x30000
0x3FFFF
RAM / ROM
4
0x40000
0x4FFFF
RAM / ROM
5
0x50000
0x5FFFF
RAM / ROM
6
0x60000
0x6FFFF
RAM / ROM
7
0x70000
0x7FFFF
RAM / ROM
8
0x80000
0x8FFFF
RAM / ROM
9
0x90000
0x9FFFF
RAM / ROM
A
0xA0000
0xAFFFF
RAM / ROM
B
0xB0000
0xBFFFF
RAM / ROM
C
0xC0000
0xCFFFF
RAM / ROM
D
0xD0000
0xDFFFF
RAM / ROM
E
0xE0000
0xEFFFF
RAM / ROM
F
0xF0000
0xFFFFF
RAM / ROM
Table 1: FRAM71B F_Block- and Configuration- Locations in BOT FRAM.
*) No Chip must be assigned to F_Block 2
F_Blocks are presented to the HP-71B in the form of memory-"Chips” that may represent a
memory module on their own, or may be clustered into larger memory modules. Chips do
not have pre-defined addresses in FRAM, but get assigned to user-selected F_Blocks. Chip
configuration data is stored in FRAM, and will survive a power loss or a "MEMORY LOST".
v
F_Block 2 must not be used for Chip-assignments.
Configuration of Chips and Memory Modules is accomplished by [POKE] commands at the
Card Reader’s address space C_0x2C000 – C_0x2C01F.
Each byte-value in that address space configures
•
The size of a Chip,
•
Whether it is part of a module that contains multiple Chips,
•
Whether its device type is RAM or soft configured ROM,
•
Which F_Block it is assigned to.
The position of a configuration byte inside the 16-byte-long configuration string corresponds
to its respective Chip, see FRAM71B configuration example on next page: