41C memory issues???

[dorff99]

On a new unit I bought off Ebay....After performing a master clear, an HP 41C should allocate 17 data storage registers and 46 program memory registers. However, this operation yields only 3 program memory registers (and 17 storage registers, as expected)

It has a memory module and the Real Estate Module.

Any comments on this or suggestions.

Thanks

[Diego Diaz]

Hi Dorff,

First thing to check would be if the internal memory is properly functioning.

Easy test:
Remove the external modules, then [MEMORY LOST] ([<-]+[ON]), SIZE 000 and [PRGM]

If you don't see 63 registers available your internal memory is faulty and will more likely require CPU board replacement.

If you get 63 regiters then chances are that the external Memory Module is damaged and causing conflict with the internal memory chip(s).

The latter may also be caused by poor contact (less likely though), please check the Memory Module in all four ports to confim that the sympthoms are consistent.

Hope this helps in narrowing the issue.

Besr regards.

Diego.

[Vintage63]

@diego, are you allowed to put a single memory module in slots other than 1? The manual says to always put them in sequencially so 1,2,3,4 if you have 2 or more.
Just wondering, nothing more.

[Diego Diaz]

Hi,

For the regular use of the Memory Module(s) the proper installation sequence is as described in the manual.

The purpose of the test I suggested in my previous post is intended to detect problem(s) in the Memory Module that can affect the I/O lines and cause conflict by interfering with the internal memory since the I/O bus is shared by all connected device(s)/module(s).

However, as noted, this case is quite unlikely.

Hope this clarifies the point.

Best from Canary Islands.

Diego.