HP portable / HP 110 Service Manual

[HeLa]

I'm a proud owner of a HP 110 Notebook (First Version, not portable plus) but the Computer doesn't work.
Can anyone send me a scan of the Service Manual? I didn't find any in the net.
Thanks Herbert.

[rprosperi]

(05-19-2016 06:23 AM)HeLa Wrote:  I'm a proud owner of a HP 110 Notebook (First Version, not portable plus) but the Computer doesn't work.
Can anyone send me a scan of the Service Manual? I didn't find any in the net.
Thanks Herbert.

Have a look here: http://www.hpmuseum.net/exhibit.php?hwdoc=48

[Dave Frederickson]

The Portable PLUS service manual might help, too.
http://www.hpmuseum.net/document.php?hwfile=6037

First thing to do, replace the battery.

[HeLa]

Thank you for your help, but the service manual for the portable plus doesn't help because the circuit has changed and the schematics alone has not enough information for me to repair my 110.
I have replaced the batterie but the unit must start even with low batterie with the mains adapter plugged in. There is nothing on the screen but I can hear a click when i try to start the computer.
Thanks herbert

[Martin Hepperle]

(05-20-2016 07:28 AM)HeLa Wrote:  ...
I have replaced the batterie but the unit must start even with low batterie with the mains adapter plugged in. There is nothing on the screen but I can hear a click when i try to start the computer.
Thanks herbert

Herbert,

about 2 years ago I also received a non-working 110. The Service manual seems to be unavailable (if one exists at all). I also heard that faint click sound, but had no display at first.

I then opened the unit and reseated all ribbon cable connectors several times. I was not able to get the machine up, but after reseating the connectors and switching / resetting the machine several times I was at least able to get a display and enter the self-test menu.
(check the manual for the contrast keys and how to enter the self test).

All self tests ran o.k. except for the RAM test, which gave me an error code. I was NOT able to link the error code to a specific RAM chip (or RAM controller or...).
The error code is similar to the codes of the HP 110 Portable Plus, but there it would indicate a ROM error - however, the ROM test came out fine on the 110. HP obviously changed the error coding scheme from the 110 to the Portable Plus.
I have procured some RAM chips but have not yet invested the time to replace chips - maybe I try just clamping a chip piggy-back onto installed chips in the hope to find the troublemaker.

So my machine is still in a non-functional condition, but I at least have an idea what could be wrong.

Good luck,
Martin

[Jim Horn]

There was indeed an HP-110 Portable Service Manual printed by HP. I had a copy and used it extensively when I had mine. It certainly came in handy when boosting the clock speed to 8MHz, replacing the CPU with a NEC V-30, reducing the wait states by 1 and boosting the RAM to 512k. All of which, including a box full of manuals, was given to another forum member at one of the HHCs years ago. Sorry that I no longer have a copy.

Doesn't anyone else out there have a copy?

The '110 is a fine little machine with a terrific keyboard. I used it for note taking and general text entry for years. Best wishes for success with yours!

[Egan Ford]

Hi, I have the service manual, but it will take me sometime to scan it. I'll try to do this weekend. Feel free to nudge me if I get distracted with another project and forget. :-)

[Egan Ford]

Scan of HP 110 Service Manual here: http://asciiexpress.net/files/hp110porta...icemanual/

[Jim Horn]

Thank you, Egan!

[rprosperi]

(06-17-2016 12:23 AM)Jim Horn Wrote:  Thank you, Egan!

Jim - If you look at the docs, you'll see some are annotated with technical notes from none other than.... Jim Horn! Funny how these things come around...

[S0N1C]

Thank you, Egan, for service manual, now at least I know how to open it

My unit has bad Lotus ROM chip, error 152 during self test. Does anyone have image? What compatible chip should I use?

[S0N1C]

Isn't it possible to replace ROM with EEPROM making some modifications to a board?

[Jim Horn]

I believe the 27C256 will drop in and go just fine. Do check the data sheets to be sure. They're available via vendors on the web, though programming them may be a challenge without a device programmer (which is pretty simple for this particular part).

Back in the 1980s lots of folks would pop the ROMs or EPROMs from devices they bought, read their contents, then tweak the code, program ("burn") an EPROM with the results and put that back into the device. Hacking as a positive pursuit has a long history...

[S0N1C]

Thank you, Jim.
I have a TL866II+ and some 27C512 chips, which I used to burn images for HP 110+

[J-F Garnier]

(08-19-2019 04:38 AM)S0N1C Wrote:  Isn't it possible to replace ROM with EEPROM making some modifications to a board?

The Lotus ROM are (IIRC) 1 Mbits type (they are using the A16 address line). In theory, they could be replaced by a 27C1024 but this EPROM is a 32-pin device and this would require some kind of adapter.
I don't know any existing image of the Lotus ROM.

J-F

[S0N1C]

It seems Lotus came in 2 x 32KB 28 pin ROM chips

[J-F Garnier]

(08-19-2019 10:51 AM)S0N1C Wrote:  It seems Lotus came in 2 x 32KB 28 pin ROM chips

Oh, this is for the 110 (not 110 Plus), and Lotus was actually in more than 2 x 32k ROM (U52,53 plus parts of U56-59).
In the 110 Plus, Lotus was in a single pair of plug-in ROM chips in the ROM drawer.

So I assume your machine is a 110 (not Plus)? Then, yes, you should be able to replace a ROM with a 27C256. Now, you have to find an image of the ROM...

J-F

[S0N1C]

Yes, not a Plus model

[S0N1C]

I only now found time to disassemble my HP 110, it is not so easy because I wanted to preserve stickers (and I did) which hide majority of the screws. So, I opened it, pulled ROMs (yes, pulled, they're in in-board sockets!) to read and then decided to install them back and check, and lo and behold ROM test completes with OK and Lotus 1-2-3 works fine, so it was probably just a bad contact with socket.

But to be sure I dumped a working copy (I don't know what type of ROM this is, so I just used generic 27C256 settings) I tried burning it to my EEPROM chips, unfortunately I have only 27C512, so not an exact match, but I filled each chip with twice as much data and installed. And they work, Lotus runs, I didn't see a difference but when I ran internal ROM test it gave me errors on both chips maybe it reads IDs? Anyway, I call this success
On a side note, my HP 110 had a poor contrast display even on the highest setting, max LCDNEG I measured was -11.6V, not sure what was the actual reason, first it looked like STEP8 wasn't working, I checked MOSFETs(Q8-Q11) and they were all fine, then I began swapping resistors and now it looked like all steps are working, I tried many configurations(late at night, so no exact recollection ) but in the end I replaced original resistors with 200K, 100K, 47K and 22K and now on the highest contrast setting it goes just a little over -13V and display is dark but readable.

[Martin Hepperle]

Can you post the ROM images? They could be useful for other people in the future.