HP integral , 82297a

Tony Duell ard at p850ug1.demon.co.uk
Fri Sep 28 19:23:44 CDT 2007

[HP Integral serial PCB]

> It really is a simple circuit on a dual layer PCB. I'm sure that you 

I am very suprised there aren't internal power and ground planes, since 
just about every other HP computer PCB of the time was built that way.

Now, IIRC, the Integral I/O cards have an ID register. Typically a '241, 
outputs to the data bus, inputs pilled high or low as appropriate. The 
idea is that the software can read the ID of each board in the machine 
(there is a slot-specific card select line on the connector), and work 
out what I/O drivers to load, etc.

Obviously the card ID is somethign I would have to figure out if I was to 
copy it. If there are internal power/ground planes, it's not going to be 
possile to do that from a simple scan of the 2 visible sides of the board.

IIRC (again), the Integral serial board uses a 68681 serial chip, or 
something similar. Strang, considering the HP9000 DIO serial board _and_ 
the intenral modem for the integral use 8250s...

> could easiliy reconstruct one if you whish so. I  can provide a scan of 
> the board.

Incidentally, i have 4 Integral expansion boards. In the machine at the 
momemt are a 1M RAM card and the intenral Modem (uses a Roxkwell 300/1200 
baud chipset). Not in the machine are the interface of the expansion box 
(since I have no expansion box) and a ROM/EPROM module (no ROMs in it).


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