FRAM71B
User’s Manual
FRAM71B 1.00
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©Hans Brueggemann, 2016
13 General
Q&A
Q1: FRAM71B is supposed to be "Continuous Memory", but I'm still getting MEMORY LOST
when removing the power supply from my HP-71B. Is my FRAM71B defective?
A: No worries! See chapter 17 for a description of your HP-71B's power-loss mechanism that
causes this behavior.
Q2: After installation, FRAM71B's LED indicator is permanently on and my HP-71B is unre-
sponsive. [ON]/[/] [3] doesn't help either. What can I do?
A: Check whether all batteries are properly inserted.
Q3: Why is the LED indicator permanently on, even when the calculator is turned off?
A: FRAM71B uses the LED as a diagnostic means. This is normal behavior while CN2-4 is set.
Q4: Can I use the memory extension as a shuttle to migrate contents to another FRAM71B?
A: Although possible, removal and re-insertion of the extension should be avoided due to
the fragile nature of the contacts. If you must remove the extension (to access the JTAG
connector) make sure to lift it vertically from its seating and avoid tilting it, as this will bend
the contacts ever so slightly and may lead to permanent read/write errors when accessing
TOP FRAM.
Q5: [MEM] displays less memory than expected and some modules seem to have disap-
peared from SHOWPORT. What gives?
A: three reasons here:
a. Your HP-71 got screwed. Do a power cycle.
b. FRAM71B's config interpreter got screwed, most likely after a power loss.
1)
Write down your configuration string C$=PEEK$("2C000",32) .
2)
POKE"2C000","0000….." (32 zeroes).
3)
POKE"2C000",C$
4)
Power cycle your HP-71B
c. The user got screwed. If you have previously experimented with the
FREEPORT command, chances are that there are unused IRAMs hiding some-
where in the FRAM, but you have forgotten about them. Unless you want to
chase them down one by one, you can remove them all at once by installing
CN2-2 and perform [ON]/[/],[3] to provoke a MEMORY LOST. See chapter 8.4
for details. Note that [ON]/[/],[3] only clears RAM chips that are configured.
Q6: I'm using the DIAGNOSTIC ROM image in BOT FRAM to test TOP FRAM. My configuration
at C_0x2C000 is "B0 B1 B2 B3". After pressing [+],[+],[4] I'm getting "P50 RAM BAD" and "P51
RAM BAD".
A: the DIAGNOSTIC ROM requires write access to test the FRAM. "B0 B1" refers to the TOP
SYSRAM area, hence you must install jumper CN2-4 to allow write access.
Q7: I have an FRAM71B-1024, and I'm running out of memory space for storing module im-
ages. What can I do?
