[rescue] Wanted, HP9816 Computer

[Patrick Giagnocavo]

Might want to have a look at the bottom of this page:
https://www.hpmuseum.net/display_item.php?hw=4

"As of 2016, we have seen only three failures in 9816 computers. One had a
non-functioning power supply as it was turned on before the proper fuse and
switch settings were made. Another unit had defective main memory. Instead
of troubleshooting the main memory, an easy way to fix this problem is to
use expansion memory as main memory by telling the CPU that memory starts
at the address of the expansion memory card (using the dip switches on the
motherboard). The final failure we encountered was a defective keyboard
control chip on the motherboard, which can be replaced."

Wonder if the person running that site would be able to assist?

Cordially

Patrick

On Wed, Oct 5, 2022 at 10:27 PM Chris Quayle <syseng at gfsys.co.uk> wrote:

> I've  been using an HP9816 computer for hpib sw development. Not used
> for  while, and now comes up with a fault on the text or graphics
> boards. When cold, get a bleep error on power up, which changes to a
> partially painted screen and cursor, when warmed up. Keyboard
> advances the cursor, but no characters visible. Replaced the 6845
> but the fault persists.
>
> I need to have this machine working as it's used as a gpib reference
> model for some os software i'm writing to talk gpib via a prologix
> network - gpib adapter. I can trap and reverse engineer the bus
> transactions and timing with a logic analyser. There are other old hp
> models with gpib, but the 9816 is self contained and compact enough
> to sit on the bench and has the HP Basic rom card for quick tests, as
> well as being a neat little machine anyway. I lusted after one of this
> model on release, 68000 cpu etc, but could never afford one.
>
> Already did a load of work some years ago to replace the memory, turned
> pin sockets and ceramic 64k x 1 devices. Looking to buy or swap another
> complete machine to do board swaps, or just the text and graphics
> boards that sit in the display section. Have a variety of old Sun boxes
> for swap if of any interest. In the UK, any ideas welcome ...
>
> Chris
>
> _______________________________________________
> rescue list - http://sunhelp.org/mailman/listinfo/rescue_sunhelp.org
>
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