GPIB/IEEE.488 Develoment Chat

[Tom Plano]

Wanted to move this over to its own thread as it doesn't belong buried in a thread about printers. 

I was toying with the idea of building out a GPIB card to control my older test equipment, and it seems like a few others also had the same ideas. Alan is the farthest along, having an actual board built up and a nice schematic he can share. I'm also including my schematic, as it is broadly similar (convergent design anyone) but with slightly different address decoding.  I also have my system in an enclosure, so my schematic assumes a daughter-board that converts from 16pin idc to the GPIB connector at the panel.

Currently neither design looks to support DMA but it may be something I look into before running off boards.

Id love to hear others thought on both designs as well as thoughts on driver code, as this will be my first crack at building a driver from scratch in ROMWBW.

-Tom

[Alan Cox]

On Tue, 14 Nov 2023 at 19:05, Tom Plano <tom.p...@gmail.com> wrote:
>
> Wanted to move this over to its own thread as it doesn't belong buried in a thread about printers.
>
> I was toying with the idea of building out a GPIB card to control my older test equipment, and it seems like a few others also had the same ideas. Alan is the farthest along, having an actual board built up and a nice schematic he can share. I'm also including my schematic, as it is broadly similar (convergent design anyone) but with slightly different address decoding. I also have my system in an enclosure, so my schematic assumes a daughter-board that converts from 16pin idc to the GPIB connector at the panel.
>
> Currently neither design looks to support DMA but it may be something I look into before running off boards.

I've not worried about DMA because I don't think many people have a
DMA card. That said DMA probably works if you hook the DMA request
lines up somewhere.

Not sure how you'd hook it into ROMWBW I guess it depends what you
plan to do with it as it's a very abstract interface and there are so
many different things and protocols stuck on top - from old lab
instruments to PET floppies and HP3000 hard disks.

Alan

[Dave White]

This PDF has an example of some driver code.

https://inis.iaea.org/collection/NCLCollectionStore/_Public/19/041/19041895.pdf

[Tom Plano]

Im wondering if presenting the gpib controller as a char device would be a clean solution. I know that most manufacturers often provided their own BASIC with extended commands for their specific equipment and specialty commands. So Im imagining a solution in 2.5 parts, the character device driver that relays

bytes back and forth over the bus, and a ROWWBW program that implements a set Commands for programmable instruments starting with IEEE 488.2-1987 common commands and adding till I have the full spec.  SCPI 1999.0 is a HUGE doc and so is going to be too big a job, but being able to add cmds in a composable way would make that a more minor issue.

Other devices like the PET and HP drives Id leave up to others, as I have no means to test against them. That said, an HP pen plotter might be a fun device to try and interface with. 

-Tom