Subject: hp-85A & 128K mem module question

From: [email-masked]
Date: Sat Mar 29 16:55:00 2003

I don't have access to my books at the moment. 

Does anyone know what command or process you would use on a HP-85A to verify 
that the 128K Memory Module that plugs into the back of The HP is working.

I seem to remember that the 85A needs a ROM to use a 128K Memory Module. If 
this is true what one?

I just looked in my 1982 HP Catalog and it indicates that the 85A cannot 
access that much memory, that it was limited to max of 112K in a certain 
configuration. I cannot find my 1984 catalog at the moment and my 85 books 
are buried in storage.

Any help appreciated.
Paxton
Astoria, OR

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From: Vassilis Prevelakis <[email-masked]>
Date: Mon Mar 31 19:44:40 2003

> that the 128K Memory Module that plugs into the back of The HP is working.

The Instruction sheet for the HP 82907A (32K), HP 82908A (64K) and
HP 82909A (128K) Menory Modules states:
    "The HP 82907A, HP 82908A, and the HP 82909A Memory Modules
     cannot be used with the HP-83 and HP-85 Personal Computers."

The note obviously refers to the HP-85A, since the HP-85B *can* utilize
these modules as RAMDISCs.

So you need either an HP-85B, an HP-86, or an HP-87 to use your 128Kb module.

> I seem to remember that the 85A needs a ROM to use a 128K Memory Module.

You may be thinking of the 00087-15012 Electronic Disk (EDISC) ROM which
allows memory to be used as RAMDISC. This ROM is built into the HP-85B
while it is optional for the HP-86/87.

Sorry.

**vp