ebay: Eramco ram storage unit for HP-41C -- how much ram, 64 Kbyt?



#7

at ebay there is a eramco RSU (ram storage unit) for HP-41C.
interesting item. it is extremely rare - it's nearly not possible to get such a item (i have never seen such a item at ebay yet, only rom/eprom boxes). how much ram does it have: 32 KByt, 64 KByt or 128 KByt ? does anyone know ?

see

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3063878983&category=11713&rd=1


Edited: 8 Dec 2003, 9:33 a.m.


#8

In an email to me he claims that it has 2 banks of 32K, as it has switch #6 which switches the banks. However, my understanding is that this model has switch #6 for ALL versions, including 32K versions. It is just non-functioning for 32K.

Does anyone know if the RSU-2 contains ONLY RAM? Is the ES-41 Database 85 O.S. software installed in RAM or ROM?

Does any RSU-2 owner know if this unit is restorable? Don


#9

I once owned one of the these Eramco Ram Storage Systems. The one with the switchs came in 32K or 64K versions. Both units had switch 6 but the 32K version had a trace cut to disable the function. The ES-41 Database 85 O.S. software was stored in the Ram at E000-FFFF. It was 8K in size. I took my apart and disconnected the battery and the OS was erased. You can get the Eramco ES41 rom and manual on this site. I am not sure if it is ES41 RSU-2 version. The design is a basic MLDL design using surface mount CMOS ICs.
My unit had 32K and I upgraded it to 64K and fixed the cut trace to make switch 6 function. I sold my unit to Ellis Easly who sometimes responses in this forum. He may still have it. Since then I came across a broken Eramoc ES41 system that did not have the dip switchs. It was software controlled. I was able to fix it. It came as a 64K unit and had Ram pads to upgrade to 128K. I did upgrade unit to 128K and still use it. If you have any more questions I can answer. Jerry


#10

Thank you very much, Jerry, for the info. It is really appreciated. Don

#11

The current price at the time of this posting is $465. It looks like it may go for well over $600 - maybe even $7-800. Evidently the bidders are not aware of the potential release of the CloneX modules and MLDL2000 from our forum members. Between you and me, I can hardly wait since my old MLDL took a dump. Don


#12

Well folks, it sold for $847. I really wanted to bid on this item, but I knew it would end up being WAY out of my price range. I just hope that the CloniX module and MLDL2000 actually become hardware. I'm suffering from Mcode withdrawl. Don


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