segunda-feira, 21 de dezembro de 2015

HP-41CV half-nut version scientific calculator

Great working condition.
Later half hut version (single SoC on the main PCB).
From 1986.

Mint battery contacts.
This machine never experienced battery corrosion.

The usual problem with HP Card Readers.
Gummy wheel  leave marks over the magnetic cards and it will need to be repaired.

HP-41CV HalfNut Tear down.
Removing the four rubber feet to undo four screws.
Interior in original condition. Never opened before.

The 5061-7255 Hybrid Memory/Display Driver  from 1895 week 50.

The 1LM2-002 SoC from 1985 week 39.

82104A Card Reader repair 

The usual problem with HP Card Readers: Gummy drive wheel

Drive wheel was cleaned and ready to receive the new rubber rings.

Machine was reset.

A program stored on a magnetic card was read successfully.

And the previous memory contents was restored.

domingo, 20 de dezembro de 2015

HP PRIME Scientific Calculator

 Take a HP-50G pouch and give it a new use. The Prime fits nicely in it.

Time to tear down the machine to have a look inside.
Undo two screws to access the battery.

Undo four screws to remove the back cover.
Use a plastic pry tool to help release the lateral latches.
Undo ten small steel screws to release the keyboard PCB.
Undo four back steel screws to release the main Processor/Display PCA.

Rise the Keyboard PCB to access the keyboard membrane.
Remove the KB membrane to access the keyboard frame assembly..

To remove the Processor/Display assembly, use a plastic pry tool to lift the white display frame.

Main PCB.  Main visible components:

- SAMSUNG S3C2416XH-40 SoC 400MHz ARM9 based processor.
- SAMSUNG K9F2G08U0C-SCB0 2Gbit 3.3Volt SLC Flash ROM memory (8-bit words).
- hynix H5MS2562NFR-E3M 256Mbit 1.8Volt DDR400 RAM memory (16-bit words).

By the way, Samsung has announced the EOL status for the SoC processor in the link above.
What will be the future of the HP Prime?
A reimplantation?

NOVATEK NT11002 1306-AD Touch panel controller, partially hidden by the flat cable.
This IC can be found in many Android devices as well.

Lifting the display assembly (in white color), reveals the touch screen input device (gray color).

Extra details from the Processor PCB.
A Buzzer reference in the PCB.
And a UART serial I/O as well.

General parts view.
The Prime uses five key sets.

The three color LED lenses on the back cover.

The battery is a pretty standard component, available in most retail shops under the Samsung cell phones accessories section.
Specs: Lithium-Ion 3.7V 1500mAh (5.55Wh)
Battery model: 484461AR

Reassembling the machine by reverse order was quite easy and took about 15 minutes.
It booted normally as soon as the battery was inserted in the compartment.

Happy 2015 Christmas holidays for all!
I'm signing out and go to the high mountains in the North of my little country, where the chilly wind and negative temperatures during the night keeps you inside home drinking with the family and celebrating the season.

segunda-feira, 14 de dezembro de 2015

HP-95LX  palmtop personal computer

Battery acid corrosion - the biggest enemy of any electronic equipment.

Self test.

Easter egg hidden inside the self test:

Use a Torx T6 screwdriver to undo the 4 screws hidden by the four rubber feet.

Intel versus NEC. In the picture:
NEC μPD71055C PIU from 1986.
NEC μPD70108C aka V20 16-bit CPU from 1986 (clone of Intel 8088)
Intel 8080A 8-bit CPU from after 1974.

BASIC on a chip.

Intel P8052AH-BASIC Version 1.1 from 1983.