23 Nov
2013
23 Nov
'13
3:03 p.m.
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-
bounces at classiccmp.org] On Behalf Of Tony Duell
Sent: 23 November 2013 21:05
To: cctalk at classiccmp.org
Subject: Re: HP-150 Touchscreen
backpalne
I remember using a PERQ during my brief time at
ICL in early 1985. I'd
love to see one in operation again.
They are very interesting machines, although many in the UK were wasted
running PNX (PERQ Unix). Quite honestly, if you want a unix box there are
other choices. PERQs are fun when they run the OSes designed for them.
I am not sure where you'd find one now. I am cetainly keeping all four of
mine (!).
[Back to the HP150]
This one does not have the printer.
Does it have the ribbon cable for the printer (it plugs into both the and the PSU board)? I might be able to find a spare
HP2674 pritner unit,
but I
know I don;'t have the cable. It could easily be
made, though.
Yes, there is a ribbon cable that comes out of the casing into the area
where the printer goes.
There seems to
be a lot plating between the capacitors and the CRT
neck, it
There is a metal bracket, but IIRC not all machines had it (or perhaps HP120s, much the xame casing/PSU/monitor, that was
often missing this
shield between the PSU and the CRT neck). But anyway it can't hurt to
check.
really would have to be a heck of an explosion to
damage the tube from
what I can see. I struggled to get the PSU out until I found the
service manual section. From what I can see all the capacitors look OK
though.
Good. That is, of course, a switch-mode PSU, and most of the circuitry is the mains side of the isolation barrier. Much like the
part of thr
H7140 you are working on...
That is a prity. The memroy board (fixed ot the CPU board) will have a
maximum of 256K on it. I think 128K machines exited, but I have never seen
one. In any caxe upgradign the RAM to 256K is not too hard.
But a lot of software needs 512K or 640K. The 384K memory board (HP45632
IIRC) is very useful.
custom
I mentioned getting insdie the card cage yesterday., You want ot do
that
to
see what you have. It';s worth seeing if you
have n expansion boards.
Sadly, no expansion cards. I took out the top card from the card cage
because the batteries have
leaked
Tht is the video board. There are a couple of 40 pin ICs on it, one is a
CRT9007 CRT controller used for the text display. The other is HP custom
1820-3091, and is the graphics controller. I think that's the only true (as opposed to programemd) IC in the machine.
used
and there is corrosion on the contact. Thankfully
it does not seem to
have
Right This is not uncommon, normally a good scrape cures it. .
done any damage though. One of the caps on the
board has a corroded
lead though. The other card looks fine.
FWIW,. the batteries conenct on the video bord, but the votlage is not there. The -ve side of the battery is groudned, the
+ve side goes ot a
couple
of adjacent pins on the backplane conenctor. It hen
goes over the
backplane
to the CPU board where it feeds into a diode circuit
and powers the real
time
clock IC (MM58167). It also ends up on the expansion
board connectors, but
I'ev yet to find an expansion board that uses the battery voltage.
spring
Yes I have already read about the config side of
things. Hopefully
while I source a battery it will work when I power it on.
That batteries are nto ahrd to get. You have the palstic holder with the contact in it, I hope. You need 2 size N cells. These
are also known as
'ladies'
(particularly in continental Europe) or LR1 cells.
I ampretty sure Farnell do them. THe Maplin I was in today had a pack of
2 on the rack. Many supermarkets keep them. At least one 'pounds shop'
sells a pack of 5 obtects -- 2 N cells, 2 A23 12V batteris (about the same
size)
and one A27 12V battery (smaller). If you get the last
pack, do be sure to
ptu
the 1.5V cells in the HP150. You do not want to apply
13.5V or worse 24V
to
the real time clock IC. I would got as far as to check
the voltage across
the
open ends of the battery nnit before putting the
holder into the machine.
It
only takes a few seconds.
I bought two batteries today from my local household goods shop. They were
definitely 1.5V each. However, it does not seem to have remembered the time
after I set it earlier. Perhaps I need to clean the contacts a bit more.
One common problem is touchscreen errors. Most of the
time this is just
dirt
collecing in the holes and block the light beak.
Occasionally the IR LEDs
and
phototranssitors fail. But it is not too hard to sort
out, and the parts
are
available.
Indeed, I do seem to have a problem with the touchscreen. I get a power-on
test error 1000 which the manual says is the touchscreen. I will look at
this problem another time though, got lots of other things I want to do
first.... I collected this machine without knowing anything about it and
thinking I might pass it on (it may have gone to waste otherwise), but I
think this is going to be a keeper, especially as it is quite compact.
Thanks
Rob