Hp 71B



#17

Hi there,

I just have got a 71B lately and I was asking myself if is possible to program in Assembly without the rom or an HP-IL link. Also, is there a way to make an HP-IL ? As I'm in an Electrical Engeenering I can do the circuit with some microcontroler but, has the protocol been Reverse engeenered ? If so, where can I find the doccument.

Thank your for your info,
Xavier LaRue


#18

There are several documents on TOS and on the museum's DVD that have detailed specs for HP-IL. These in particular ought to be of interest:

  • Hewlett Packard General Purpose HP-IL Interface Integrated Circuit 1LB3-0003 (TOS)
  • The HP-IL Interface Specification HP Pub. 82166-90017 (TOS)
  • Firmware Design for HP-IL Devices - HP Application Note (Museum)
  • The HP-IL System: An Introductory Guide (retrocalculator.com)
  • HP-71B HP-IL Internal Design Spec, Volumes 1 and 2 (Museum)

The museum DVD may be purchased here. If you need a pointer to TOS, email me at hbo@egbok.com.

HP made a series of ICs that implemented the HP-IL protocol. You can probably scavange chips from old, non-working hardware. Here's a partial list of devices that had HP-IL, and thus the IC in question, built in:

  • Thinkjet HP-2225B
  • 9114, 9114B floppy drives
  • 3421A Data Acquisition - Control Unit
  • 3468A Digital Multimeter
  • 82161A Digital Cassette Drive
  • 82162A HPIL Printer
  • 82163 HPIL Video Interface
  • 82164 HPIL-RS232 Interface
  • 82165 HPIL-GPIO Interface
  • 82166C HPIL Converter Kit
  • 82169 HPIL-HPIB Interface
  • 82905B Printer
  • 82973A HPIL/ISA Interface Card
  • FSI164A HPIL RS232 Interface
  • HP-110 and Portable+ Laptops
  • Add on modules for HP-85 and HP-150 computers

Cristoph Klug makes a reimplementation of the 82973A ISA card. If you were to implement a PCI card, I'd buy one. 8)

Regards,
Howard

Edited: 2 Feb 2006, 1:49 p.m.


#19

Or USB, better yet!


#20

Hi there,

Happy to see that somone would be interested into what I'm
planning to do.

I'm planning to make a cable to remplace de ISA card using
eather RS232 or USB [ I'll make it with a microControler ].
So I need to find the doccumentation about the protocol and how
it works.

I'll need any information that you know on the HP-IL protocol.

Thank you for all your help :)
Xavier LaRue


#21

Well, all the references I listed above would be helpful.

HP shipped a development kit for HP-IL. It contained four of the 1LB3-003 HP-IL ICs, supporting electronic parts, a couple of HP-IL development modules for the HP-41C, an HP-IL translator, which was some sort of demonstration implementation, plus a lot of documentation. "The HP-IL Interface Kit Technical Guide" contains an overview of the kit. It recommends the following documentation, all of which I listed above: "The HP-IL System" is a book-length tutorial on implementing HP-IL. "The HP-IL Interface Specification HP Pub. 82166-90017" is the most useful document for what you have in mind. It has all the state digrams for the protocol, and exhaustive specs for the logical and electrical properties. Taken together, those two should have enough information for what you want to do. If you decide to take the route of scavanging HP-IL ICs of old hardware, then the "HP-IL Integrated Circuit User's Manual" will also be useful. In might be good to have in any event, just to compare the implementation to the spec. The first book is linked to above. The other two can be found at TOS.


I'm not an EE. I'm a systems software guy with a serious addiction to old computers and networks. I studied the documents listed above with an eye toward writing a Linux driver for Cristoph Klug's ISA card. But I ended up cobbling a solution together with DOSEMU and JF Garnier's EMU41. That got my PCs and my HP-IL gear talking, so the itch got scratched, and I shelved the project. I'm not sure how much help I'd be to you beyond pointing you at the right documentation. But I'm glad to help out any way I can.

One issue I see is the loop vs the point-to-point nature of serial links. How were you planning to handle that?

Regards,
Howard

#22

The HP-IL interface generally consists of a controller, two pulse transformers for line isolation and the connectors.

Reverse engineering the controller will be tedious but doable since the specs are out there (see Howard's post above). However finding replacements for the transformers and connectors will be tough.

I'd suggest you forget about HP-IL and think about creating a USB or RS-232 interface for your HP-71B instead. This interface can fit within the HP-IL controller cavity and will be far more useful than the (obsolete) HP-IL interface.

Just my two cents

**vp


#23

On the other hand, an HP-IL solution would work for the HP-41, HP-75 and HP-110 as well as the HP-71, increasing the potential market for a hobbyist product.


#24

I'll see,

The point is the if I find all the needed info, I'd like
to make product that work with every HP-IL compatible, calculator.

What I need it the documentation.

Thank for your help,
Xavier LaRue

#25

Howard Owen wrote:
> On the other hand, an HP-IL solution would work for the HP-41,
> HP-75 and HP-110 as well as the HP-71, increasing the potential
> market for a hobbyist product.

Maybe I misunderstood, but I was left with the impression that he does not have the HP-IL interface fpr his HP-71B and that he is looking to make a new 71B HP-IL interface.

How is that going to be of any use to an HP-41 owner?

Another idea would be the card reader port. It provides access to the internal bus so you can hang there a microprocessor with Flash (something like Diego's NOVRAM module). Then you can download programs to the flash and the 71 will find them mapped in its address space.

**vp


#26

I think you may have missed this part, Vassilis:

Quote:
I'm planning to make a cable to remplace de ISA card using eather RS232 or USB [ I'll make it with a microControler ]. So I need to find the doccumentation about the protocol and how it works.

Regards,
Howard

#27

Quote:
This interface can fit within the HP-IL controller cavity and will be far more useful than the (obsolete) HP-IL interface.

HPIL is obsolete only in that it is out of production. It's good for only the medium speed of about 5,000 bytes per second plus overhead (even USB 2.0 may not be able to go any faster with an HP71 though), but HPIL has a lot of benefits over other interfaces. It allowed simultaneous interfacing to anywhere from one to hundreds of other devices with a single pair of small, inexpensive connectors and no external hubs, was plug-n-play, did auto-addressing and error-checking, every device knew what it was and what it could do, it supported hot-swapping and interrupts, had 1,000-volt isolation between any two adjacently connected devices (by the pulse transformers), and allowed passing control from one controller to another if you had two or more controllers on the loop. There were interface converters to the other major interface types-- parallel, RS-232, and HPIB (IEEE-488). Being less expensive and more intelligent than HPIB, it should have become an industry standard, but unfortunately HP marketing killed it like they did the 71. The 71 was made for technical professionals; but not one in ten of them knew it existed; and of those who did know, not one in ten had any idea how much power it had.

USB is the common interface now. It's faster, but it has the huge disadvantage that you need an additional port for each thing you want to connect. (That's a problem when you have limited space for connectors, like on the 71.) Distance is more limited too. Again there are converters to the different interface types though, so a USB port can be connected to RS-232, HPIB, and hubs to more USB ports.

The only other interface I can think of right now that had the isolation like HPIL is MIDI, which uses optoisolators instead of pulse transformers. The optoisolators made it less suitable for low-power hand-held operation, the connectors are bigger, and its fixed speed is slower, at 31.25kbps. It did allow daisy-chaining, but there was no error-checking.


#28

Quote:
Being less expensive and more intelligent than HPIB, it should have become an industry standard, but unfortunately HP marketing killed it like they did the 71.

As the experience of the following thirty-odd years has showed, standard technologies are more likely to succeed than proprietary ones, absent a monopoly. That's because competitors can usually implement the standard on easy terms, often for free. And if there's an installed base already, a company will want to adopt the standard so as to be compatible and familiar to the existing customers. HP-IL was published, but not standardized, remaining an HP-proprietary technology. HP-IB was published and standardized, as IEE-488. HP-IB lives on as GPIB, and has been extended several times to keep up with increased data rates and other advances. HP-IL never went beyond the basic implementation of the loop. Controllers were upgraded, from the 41 to the 75 to the 71, and half-heartedly to the HP-85, (the HP-110 and HP-150 weren't intended as instrument controllers,) but HP-IL died a death in obscurity. It's a pity, no doubt.

#29

With a bare 71B, you can program in assembly language by using POKE, PEEK, etc. It's quite a hassle though, so I don't especially recommend it. You really should either buy the assembler ROM or the HP-IL interface and an HP-IL to serial converter.

Buildinng your own HP-IL interface for the HP-71 would be a very large undertaking; it's not enough to just build something that emulates the microcontroller and 1LB3 chip in the HP-IL module. In addiion to needing to write a fair amount of firmware for the microcontroller, you would somehow need to have a copy of the HP-IL ROM code that runs on the HP-71.

The protocol has not been reverse-engineered, because HP actually published all the relevant specifications. They're on the MoHPC DVD or CD set.


#30

As Said earlier, I'll see, when I'll get my hand on
the documentation, It shoul'nt be to much hard to interface...

We will see,
Xavier LaRue


#31

The point is that I love playing with uC, so, this is only
a bus with some protocol. We will see for an RS232 interface
but it should not be that hard.

The Assembler Rom and/or the Linking interface cost too much
for my budget.. so :)

Anyway, I'll continue my research and see for the Museum CDs.

Thank you all,
Xavier LaRue

ps: I still need to receive my hp71B. Its due for the next week :)

#32

Quote:
It shoul'nt be to much hard to interface...

I think you'll find otherwise. I did HP-IL product development for a while, and even WITH all of the HP specifications, it still took months of hard work to develop a microprocessor-based HP-IL device, make sure that all of the necesary state machines work correctly, etc.

This isn't a simple interface like RS-232.

And for what you're talking about doing, you need to interface the the Saturn microprocessor bus too, which is more complex than a typical microprocessor bus of the 1980s.

It's all quite possible, but it's also quite a time sink. So unless you simply have a lot of time on your hands, you're definitely better off buying the interface than engineering your own.


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