RPN and HP-IL

[Nigel Clayburn (UK)]

This posting is prompted by my finding an old file in my garage.

1) RPN

There have been some discussions about the merits of RPN but I have never seen anyone quote any 'scientific justification' as to why RPN is better system for doing calculations (you don't have to convince me). To that end I offer this reference:
S J Agate & C G Dury ' Electronic Calculators which notation is better' Applied Ergonomics March 1980 11.1 pp2-6. It claims to show that RPN is better than algebraic entry for both technical and non-technical users.

2) HP-IL

Some time back there was a comment that the hp-il integrated circuit was going to be second sourced by National. I have a copy of this pre-publication data sheet complete with editorial comments. The IC was going to be NSC851 or (859). The data sheet runs to at least 96 pages and is mainly a conflation of the HP-IL spec and the HP-IL IC data sheet.

3) European HP-IL

Grabau Computertechnik GmbH made the GR7 Graphics Video Controller which as well as an 80 col text display would also interpret HP GL commands.
I toyed with buying one to go with my 71B but at 1690 DM (late 80's price) I could not justify the cost either as a personal purchase or to my management.

Kristal S.A Informatique, Gieres France offered the 'REGAL' system providing A/D, digital I/O, Relay and microprocessor functions on eurocards linked with HP-IL. Also an analogue output card for the HP3421A Data Acquisition Unit. The picture shows that they took the IL transformer and IC and integrated onto their PCB rather than provide it as an add-on sub assembly as in the Grabau unit.

4) HP-IL protocol.

This is an email reference to the use of HP-IL protocol using 6805's and a PC on RS232 with PASCAL by Marek B. Kaminski (mbk113@rsphy.anu.edu.au).

Finally a question. I recently acquired a Portable Plus and after replacing the batteries it now appears to be a working one. What is type of charger required? As it has the same fitting as the HP9114B Disc drive and the battery is of similar electrical capacity can one use that charger (8V 3VA). Thanks.

[Philip]

I find your information interesting. I would be interested in a copy of the NS Spec if possible to get it scanned. I'm also interested in your reference to the HP-IL Protocol over RS232C, is that reference email current or have you tried it.

The power adapter for the Portable Plus is the 82059B (same as the 9114B, thinkjet, IL peripherals and the HP 41/71). I too have aquired several Portable Plus's with various ROM's, including Basic.

[nigel]

philip

Thankyou for the confirmation about the portable plus charger.

If you have the HPIL Spec and the HPIL IC Spec ( on Museum CDs) then you have most of the information already except for the front page which follows National's format. If you do want the full spec I could get it copied and sent to you. However I am away over Christmas till the New Year and not sure what my net access will be over that period.

Herewith is the full text of the emails relating to the HPIL/6811 etc. I tried the Kaminski link but it bounced. A further search of the Australian National University, Canberra might turn up something, or on 68HC11.

Email text:

Re : Networking 20 HC11 with a PC

Sylvain Bissonnette (bisson@CAM.ORG)
Mon, 24 Jul 1995 20:32:08 –0500

Marek wrote:

I don’t know WHAT you want from the protocol. A few years ago we implemented a ‘software HP-IL’ using 6805s and it worked fine, but we had certain assumptions (wanted group control, didn’t care about efficiency). Mail me if you want more details. Yes, you can get a HP-IL card for the PC.

Hi Marek,
Can you tell me more on your software HP-IL?

Thanks for your reply
Sylivian Bissonnette
Bisson@cam.org

Bisson@cam.org ! Check to the home of 68HC11
!WWW
Silvain Bissonnette ! http://www.cam.org/~bisson/
8382 DeFougeray !
Anjou, Quebec. !
H1K 1K6 !
CANADA !

Re : Networking 20 HC11 with a PC

Marek B. Kaminski (mbk113@rsphy1.anu.edu.au)
Tue, 25 Jul 1995 01:29:17 –0500

Hi Marek,
Can you tell me more on your software HP-IL?

Sylvain Bissonnette
Sure can;

GENERALLY the HP-IL is a serial HP-IB (BP-IB, IEEE488 etc). It’s a loop (physically and logically). You send something and you listen till it comes back, then you know that the loop is alive. THIS STOPS ALL ACTION if only one station on the loop goes down...........

The protocol requires transmitting 11-bit entities (we called them chunks), out of which up to 8 bits can be data. We implemented it as two bytes (16 bits) with 5 bits wasted. The software we wrote controlled all operations on the bus as well as in the ‘devices’, ie. things we wanted internetworked (power supply controllers / monitors).

Physically it was just RS232, TX, RX and GND. The controlling PC ran a PASCAL driver which orchestrated all actions.

As I stated we did not need or expect big bandwidth; we HAD to be able to address more than 1 device at a time and perform group control (triggering), so we had to use something from the control world and not communications world.

I know that RS232 is only a point – point connection, and we did not abuse it. Each station on the loop did data recovery / resending (this also affected throughput –software retransmission.......). So if you are desperate to have the network without extra hardware, this might be your choice.
Cheers, Marek.