Bits and Pieces for Sale

When I make replacement parts or useful items for my personal use with HP calculators and computers I sometimes have to buy more components that I need. This is usually caused by minimum order limits or high shipping costs of retailers. Also, when the "manufacturing process" is set up, it is sometimes not much extra work to produce two items instead of a single item.  Also some of the items easily available in the US are difficult to find in Europe. Therefore this offer is more interesting to European HP enthusiasts.

Additionally, I sometimes acquire lots which include some parts that I do not need.

Therefore I offer some surplus items on this page - not to make a profit but to help out other enthusiasts.

Note that these bits and pieces are available only in very limited numbers (usually one or two pieces) and are sold without commercial interest. I have acquired or created these items with the knowledge of my engineering background, but I have to exclude any liability or warranty. It is your risk to operate these things properly. If you don't like this you should not ask for anything offered on this page. Any selling price is set to cover my cost for parts and shipping.

If you would obtain an item, send me an e-mail using this link: Martin Hepperle.

Current Stock (April 2020)

HP-IL Cable Kit

In order to create the DIY HP-IL cable I had to buy a larger number of connector pins and plastic parts. As I do not need all of them I offer here a limited number of parts to build your own cable. Note that this requires some mechanical, gluing and soldering skills (see the detailed description here)). Each kit contains parts for one cable, i.e. two sets of housings together with male and female connector pins (one pair of each). I do not supply the cable as you might better decide which length and color you prefer. The parts are made of sintered polyamide (Nylon) and thus very robust but still slightly flexible.

Note that the accuracy of the rapid prototyping process is relatively variable (approximately +/- 0.2 mm) so that the connectors will not be as accurate as the original HP-connectors. If you want to have the perfect fit, buy the original cables if you can find them.

Prices for one Cable Kit

15 € (including shipping to Germany)
19 € (including shipping to Europe)


HP-IL Cable Pin Sets


I had to buy a larger number of connector pins. As I do not need all of them I offer here a limited number of pin sets to build your own cable.  These pins can also be used to repair e.g. mechanically broken HP-71 interfaces and to fix similar problems.

Each kit contains male and female connector pins (one pair of each).
It does not include parts for the housings nor cables, just the pins.

Prices for one Pin Set (2 male + 2 female pins, as shown in the picture)

7 € (including shipping to Germany)
8 € (including shipping to Europe)

HP 9114A/B Battery Charging Cable

One end of this cable plugs into a 9114A or 9114B battery pack and the other end has two connectors for a battery charger. This cable enables you to charge and discharge the battery pack outside of the disk drive with a more sophisticated charger. Especially the HP charging circuit in the 9114A is very primitive and not optimal for long battery life. The 9114B circuit is better but also limited. Therefore I prefer to use a more sophisticated charger to obtain a long life of the battery.

Today we have very nice universal chargers with optimized programs for various types of batteries (LiPo, Pb, NiCd, NiMh). These handle the battery with more sophisticated algorithms. Small but well designed  chargers can be found in a good R/C model hobby shop or mail order house. I use one with a 12V power supply so that I can even charge batteries from a car battery if needed.

The plug for the battery side is rather difficult to obtain in Europe, therefore I am offering this cable here.

Prices for one Cable

10 € (including shipping to Germany)
14 € (including shipping to Europe)

HP 9114A/B Power Supply Unit


This power supply package plugs into a 9114A or 9114B disk drive. You do not need the battery pack anymore and can operate the drive continuously.

The Euro-style plug of the power supply can be plugged into a 110/220V AC power socket at 50/60Hz. This is the standard in many European countries - if you live in a place where they do funny things like driving on the wrong side of the road you have to supply your own adapter.

With its rated output of 6V DC and up to 4A the small power supply provides more than enough power for the 9114 devices. Under certain operations these draw peak currents of up to 2 Ampθres. Using this power supply eliminates the problem of exhausted batteries which often makes these nice disk drives cumbersome to use.

The socket is attached to a box which fits snugly into the battery compartment inside the 9114 housing. The black tape forms a handle for pulling the box out of the compartment. While the power supply side uses a standard 5.5/2.1 mm plug the 9114 side uses the matching socket, which is difficult to find in Europe.


25 € (including shipping to Germany)
30  € (including shipping to Europe)



Set of Printer Belts for HP-85



Like most HP gear with flexible parts, all HP-85 computers suffer from failing  belts in the printer mechanism. Over the years the softener chemical does its job all too well so that all those rubberized parts become unusable. This is the sad part of the history of the plastics age.

Luckily the two belts are fairly easy to replace if you follow the service manual and other instructions which can be found on the internet. The only critical thing is to adjust the tension properly so that the belts are not too tight. If the belts are very tight, the motors draw too much current and burn a fuse on the printed circuit board (guess how I know).

While these belts are identical to the original HP spare parts in width and tooth count and dimensions, they seem to be a tiny bit thicker than the original ones. In order to insert the long belt into the slot in the print head I had to use a file to make the teeth side of the belt thinner (maybe by 2/10 mm) in the area where it should go into the slot. This is no big deal and does not affect the proper operation at all, you should just know this "trick".

The set contains two brand new belts for a complete overhaul of the printer drive mechanism.

Price for a set of two belts (short and long)

16 € (including shipping to Germany)
20 € (including shipping to Europe) 

Thermal Paper for HP-85




The HP-85 is a nice machine and after its printer mechanism has been repaired you surely want to make use of the printer. Unfortunately the width of the paper is non-standard and almost impossible to find.

Therefore many users are very careful not to print too much which is a pity. Especially when demonstrating the machine the built-in printer is always an attraction. On the other hand old original paper may not produce very crisp printouts (depending on storage conditions). While you can buy a roll of re-manufactured paper in the US, shipping costs, custom fees and taxes make this a rather expensive joy.

Therefore I had black printing paper of the proper width custom made (as a replacement for  HP82954A). Due to a minimum order requirement I now have a few more rolls than I need and offer the surplus here.

These rolls are made of paper with a specific mass of 55 g/m² which is close to the original paper. I did not select thicker paper because this would cause more friction at the print head and might reduce the service life of the valuable print head. At a print intensity setting of "4" the printouts are crisp. The core of these rolls is sized so that you can use the original plugs - no special spool is needed. Each roll is about 100 mm in diameter and has approximately 130 m of paper. Each roll weighs about 800 g.

Prices for one roll

12 € (including shipping to Germany)
16 € (including shipping to Europe) 

Prices for two rolls

20 € (including shipping to Germany)
26 € (including shipping to Europe) 

Prices for four rolls

38 € (including shipping to Germany)

RedEye Infra-Red Reciever

NEW in May 2018

Here I offer a receiver for HP calculators with infra-red printing functions. The receiver is built according to the description which can be found on this web site. It consists of the Infra-red receiver with an integrated Arduino microprocessor and a USB-to-Serial cable. The device is ready to use, you can use it with any terminal software like Teraterm or with Christoph Gieίelinks infra-red printer emulator software. The device is configured for a baud rate of 115200, 8 bits and no parity.

The device as shown uses a Chinese Prolific USB-to-Serial converter cable. I use them on computers with Windows XP and Windows 7 operating systems.

Some recent versions of the Windows operating system block these chips even if they work properly. The latest driver software for these systems checks for the chips and does not install the driver. The drivers also block the original Prolific chips of the same type. In this case you have to install older drivers. As far as I know this problem does not exist with Mac-Os and Linux. If you search the internet for „Prolific driver installation“ you will find solutions which drivers to install and how to do so.


I also have another version where the USB-TTL converter is built into the case and you have to supply a USB-A to USB-Micro cable to attach it to your computer.
This variant uses a Silicon Labs CP210x USB-to-UART chip.


Price (1 available of each version)

40 € (including shipping to Germany)
45 € (including shipping to Europe)

Cable for HP 2225 ThinkJet

NEW in May 2018

This is a flexprint cable which can be used to repair a broken any HP 2225 ThinkJet printer. If these printers are stored for a long time with a cartridge installed some small amount of ink will seep out of the cartridge and interact with the contact area and the fine traces in the flexprint cable. The resulting corrosion leads to an ugly print with missing dots.

On this web site you will find instructions how to modify the new flexprint cable by building an interface adapter so that you can use your ThinkJet again.  In addition to the cable you will nedd an FCC connector and a short piece of ribbon cable (see description). The cable comes with a cartridge holder which you discard.


20 € (including shipping to Germany)
24 € (including shipping to Europe)

SanDisk PCMCIA Memory Card

NEW in September 2017
Used SanDisk 256 MB flash memory card with PCMCIA connector.

I bought several of these cards, but only need one.

Tested with HP 100LX - therefore suitable for 100LX, 200LX, 1000LX and similar devices.

Price for one Card

11 € (including shipping to Germany)
16 € (including shipping to Europe)

69754A 32 Channel Relay Scanner


Plug-In board for a HP 6942A Multiprogrammer.

Attached is a cable with plugs mounted nicely on board. Obviously used, but looking nice and clean.

Sticker on back says: 69754A USA  2446A-01348


30 € (including shipping to Germany)
35 € (including shipping to Europe)

Memory Board for HP 9000-200/300

HP 98256A

Genuine HP 512 KB RAM Memory board.


40 € (including shipping to Germany)
45 € (including shipping to Europe)

[original price was $1000]


HP-HIL Board for HP 9000-300

HP 98561-66530

Human Interface board for Series 300. Contains HP-IB, RS-232, HP-HIL, Speaker. Probably pulled from a 98561 Series 300 machine.


45 € (including shipping to Germany)
49 € (including shipping to Europe)


Graphics Board for HP 9000-300/400

HP 98287A

Graphics Interface board with M.A.D. output bus for the 98700H high resolution graphics system. Probably for HP 9000-300 and up. Unused from spare parts lot.


40 € (including shipping to Germany)
44 € (including shipping to Europe)


GPIO Board for HP 9000-200/300


HP 98622A

GPIO interface board, together with genuine (but heavy) HP cable. Includes shrink wrapped installation manual pages. Unused from spare parts lot.


48 € (including shipping to Germany)
55 € (including shipping to Europe)

[original price was $355]

BCD Board for HP 9000-200/300


HP 98623A

BCD interface board, together with genuine (but heavy) HP cable. Unused from spare parts lot.


48 € (including shipping to Germany)
55 € (including shipping to Europe)

[original price was $385]

ADC Board for HP 9000-200/300


HP 98640A

Analog-to-Digital converter board, with genuine HP adapter PCB. No slot cover or thumb screws, no screw terminals on adapter PCB. You can solder wires directly to this board or add screw terminals. Unused from spare parts lot.


50 € (including shipping to Germany)
56 € (including shipping to Europe)


DMA Board for HP 9000-200/300

HP 98620A

DMA Controller board. Unused from spare parts lot.


45 € (including shipping to Germany)
49 € (including shipping to Europe)

[original price was $500]



HP-HIL Audio Remote Extension


HP 46082

HP-HIL Audio Remote Extension box. Used, some Velcro on bottom.

Two boxes are needed to extend the keyboard/audio link via a cable with 15 pin D-SUB connectors. I have not tried this system.


10 € (including shipping to Germany)
14 € (including shipping to Europe)