HP 9915A (industrial version of HP 85A)

From: Joe <rigdonj_at_cfl.rr.com>
Date: Mon Oct 14 08:55:56 2002

At 01:25 AM 10/14/02 -0700, you wrote:
>Hi Joe:
>
>At 09:37 PM 10/13/02, you wrote:
>> I'm sending a copy of this reply directly to you as well as replying on
>the list so I can be sure that you get a copy.
>
>Thanks. I subcribed to cctalk, and will dump cctech once it seems like
>posts are coming through -- looks like I'll miss stuff otherwise.
>
>
>> No, the 85B has more memory (32k vs 16k) than the 85 (aka 85A) but it's
>standard memory and not RAMDISK memory. The E-Disk ROM MAY be able to
>convert all or part of that to RAMDISK but it would leave you with no user
>memory. FWIW The 128k memory cartridge is strickly for RAMDISK memory, it
>can't be used for regular memory.
>
>Ahh. Knew there was something about ramdisk in there. I actually have a
>64K expansion card.

   Right, that's also memory for a RAMDISK. I wasn't aware that it had the extra sockets in it. Do you know what type memory it uses? The 128K cartridges are in high demand, it would be nice to upgrade the 64k cartridges.


 I opened it up to find a second row of chips not
>installed, so I suppose I could make it a 128K if ever needed.
>
>
>>Also I'm pretty certain that 85B does not have the I/O and Mass Storage
>ROMs built-in. The HP-85F has those built in and it looks like an 85B and
>says 85B on the front but it should have a metal tag on the back that
>identifies it as an 85F. The 85F were delivered as part of various HP test
>systems and AFIK they were never listed separately in the HP catalogs.
>That's probably why few people have heard of them and may be confusing
>their capabilities with standard 85Bs. The 85F is a nice catch IMO, you
>gain two ROMs and don't use up any of the ports on the back.
>
>I have not heard of an 85F before. I was pulling my 9915A apart, and found
>six ROM locations under the module card cage. I also just noticed a post
>from someone about it too. There is an I/O rom and a 9915-specific rom,
>and four spare locations.

   The second ROM is either a Program Developement ROM or a Matrix ROM, I forget which. The extra sockets are there for the user to add custom ROMs. It appears that HP expected the 9915 owners to develope their own programs and burn them into ROM for the 9915 but it never happened. The ONLY person that I'v ever talked to that had done it was someone from HP. It costs a bundle to get all the stuff that you needed. At the very least you'd need the Program Developemnt package, Assembly Language ROMs and programs, Serial interface, EPROM burner and a HP-85 to do the development on. PLUS the 9915!

   Joe
Received on Mon Oct 14 2002 - 08:55:56 BST