Hello, Tony; thank you for your answer.
Tony wrote:
<< A kludged way of getting the connectors it to cut an HPIL cable in half and solder the cut ends to your circuitry. Not as neat as the proper panel-mount connector, but it'll work.>>
Yes, I'm lucky having a spare cable, but I'll try keeping it intact (cutting it will still allow me to connect more than one only IL device in the loop, I know; I just want to keep it intact). If I can find an unused I/O connector, better.
<< As regards the transformer, electrically-identical transformers were used in _every_ HPIL device I've worked on, even things like the HP71 IL module. So you can raid a broken HP71 IL module (or whatever) for the transformer. One day I must dissect the dead transformer in my junk box (shorted turns) and count the turns, etc, so I can attempt to make a replacement.>>
I know about a guy that built an HPIL transformer. I'm no longer in contact with him (I saw him by the last time in Petrópolis, Rio de Janeiro, in 1989), but I remember he told me he used three toroydal ferrite cores and computed the number of turns based on the IL signal's frequency and waveform. I was not smart enough to ask him for the "recipe", so I'll try to do my best. Anyway, if you count them down...
Hewlett-Packard Journal, January 1983 issue, is a very good source of information. It has a brief, concise description of the electrical parameters and a simplified schematics of the IN/OUT IL stage. There are indeed three transformers, and their primary-secondary relation (2:1 / 5:43 input, 3:1 output) is mentioned. If I have at least one number of turns for each...
<< Do you have the 1LB3 HPIL interface chip, or are you planning on managing without it? HPIL is not trivial at the hardware level, so I'd try to get a few of those chips as well.>>
Yes, I know. In the same HP Journal issue we can see the internals of the HPIL IC, the ILB3. Somewhat complex fellow, han? Well, I believe for the time it appeared there was no other "easy" way to achieve an HPIL communication. But I'd like to know if there are no other controllers nowadays that would allow the IL protocol implementation easier. I thought about ATMel controllers (if I am not wrong, Pavel Korensky is/was working with them), or some Microchip PIC's, I don't know. My starting "project" would be simply a dummy buffer, that would capture any group of bytes from a starting code (byte) to an ending code (byte). Just a single binary, ASCII-coded character sequence that would not harm any other device in the loop. I believe it's easy to arrange, mostly because I have an Extended IO module.
This buffer would allow a dot-matrix, graphic LCD to show images and text sent from an HP41. Basically a record-only RAM and a microcontroller dedicated to IL comms, being continuously scanned by the LCD's controller.
BTW: I was told you, Tony, have some programs that allow LIF disks to be read (manipulated too?) by Lynux-based machines. Do you have them? Are they available to download? If not, can I have a copy of them? What to do?
Well, I wrote too much. Is there anything else somebody would like to add? Please?
Thank you.