HP-85 Re: anyone in rochester?

From: Joe <rigdonj_at_cfl.rr.com>
Date: Sun Aug 31 22:19:22 2003

At 11:50 AM 8/28/03 -0400, you wrote:
>Joe <rigdonj_at_cfl.rr.com> wrote:
>> > BTW I have finally managed to get a 98155A keyboard for my 9915's
>> Congradulations! Where did you find it? It took me years to find one.
>On eBay, for $35

   Boy, what luck!

>as you can see I used the Buy Now option, and not a moment too soon,
>the seller told me that he had higher offers from others that came
>> GREAT! I've been looking for those for years. The only one that I have
>>is for networking the 9915s.
>Do you mean the system for making backup tapes with a bunch of
>9915s connected via HP-IB? Do you have the s/w for that pac?

   No. I don't think there was any. They might have given the listing in
the manual. I'll try to find it and see.


>"Jay West" <jwest_at_classiccmp.org> wrote:
>> What about the 9122?
>you'll need the EMS ROM for that one.
>> I'm hoping it would work with the 9122, which is what I want to get for my
>> 1631D. The only reason I'm hunting for 9122 instead of 9121, is I thought
>> the floppy disks for the 9122 might be easier to find (they DO use
>> media right?)
>The difference between the 9121 and the 9122 is that the former is single
>sided and the latter double. Apart from that they both use the DOUBLE
>density format which is different from the QUAD density PC floppies.
>So while you gain in capacity with the 9122, you still need to find these
>BTW note that while the 9121 is very reliable, there are quite a few
>9122s with damaged heads. This has to do with the disk loading mechanism
>that gets stuck with age and if the user forces the diskette in, it
>hits one of the read/write heads.
>> Thanks for the tip!! I don't have too many old DECtapes, but when you say
>> old 40mb PC tape drive tapes, are you talking QIC-80 tapes? I have tons of
>> those. If not, exactly what tape do I go buy?
>CAREFULL! The HP-85 tapes (and the DECtapes) are NOT the same as the
>QIC-80 tapes. They look the same, to the extent that I was trying to
>insert one and getting annoyied when it wouldn't go in.
>> I saw note of that on your website. That would be soooooooo so nice to have
>> n ROM emulator. Humm there can't be THAT much to the electronics inside the
>> 2929A. Anyone have one they'll let me take apart and build a copy of?
>Actually its not that complex. If you look at
>you will see that most of the chips deal with address decoding. You can
>replace most if not all with a microcontroller (e.g. PIC).
>BUT, (there has to be a but, otherwise, I would have already pointed
>you to a page that tells you how to build one :-) The HP-85 bus is
>not TTL. I think the logic true is +6V and the clocks are like +12V.
>So you need more than a PIC. Like I said, its in my TODO list.
>Having said that, relocating the ROM executable may actually be easier.
>But (there's that word, again) when I tried to look at the CPU
>architecture, I freaked out. What the **** were they doing back then.
>This CPU is totally wierd, so understanding what is going on with
>that thing will take some effort.
>Anybody who knows/remembers HP-85 assembly? :-)
Received on Sun Aug 31 2003 - 22:19:22 BST

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