AR488 Arduino-based GPIB adapter

[tom_iphi]

Hi wb0gaz,

such solutions are already available, albeit not using the AR488 adapter.
There is the standalone GPIB disk emulator:
https://www.qsl.net/in3otd/electronics/HPDisk/HPDisk_OTD.html
As you have found out there is also the hpdrive solution.
I have set up/built both and they work very well and are very versatile.

[wb0gaz]

Thanks, Tom --

Aware of the two existing solutions.

My posting was more based on an interest in open source solution (and as I've been doing embedded storage since Western Digital FD1771 with 8080 in 1977 and DEC RX01 emulator for LSI-11 on Z80 8-bit machine in 1979, my interest was also in extending AR488's use case options as a collaborative development project.) I'd like tackle something considerably more modern, like GPIB Floppy (ca. 1985?)

[WaveyDipole]

Just "discovered" AR488 today, and in lieu of immediately reading through 43 pages of postings here, would it be possible get a pointer to contemporary resources, particularly that might let me build based on ATMEGA644P.

1. Schematic/pin assignment guide
2. Firmware
3. Configuration/test guidelines?

I have on hand ATMEGA644P (SMD), 75161/75162 (DIP) and GPIB male/female right-angle PCB connectors from prior projects that didn't go forward, so I'd like to use those and would be happy to do my own PCB layout.

Thanks, and hopefully these (redundant) questions will send me on my way!

Some time ago, I co-laborated on another project where a we built a 4924 "tape drive" emulator for the Tektronix 405x series based on the MightyCore 644 or 1284 boards with an attached SDcard reader. I had contemplated the possibility of adding a module to support the Tektronix disk drive but never got around to it because I don't have one to test and compare. I would imagine it would work in a very similar way for the HP in principle, just have to respond to a somewhat different command set:

https://github.com/Twilight-Logic/AR488_Store

The tape functions do not have a method for switching directories for example, but otherwise, the basic features for storing, erasing and retrieving files are there. The SD storage format would also need to be changed to suit a disk drive emulation so there would still be plenty of work to do. I do still have the Tektronix 4051, but unfortunately I don't have a HP computer to work with.

If you have a look at the AR488_Layouts.h file in either the AR488 or the above linked project you will find a definition (AR488_MEGA644P_MCGRAW) for the pinout we used for the 644 and 1284 boards. The definition will be automatically selected when this board is chosen in the IDE. Monty McGraw also designed a board for the project that allows the 644 and IEEE488 connector to be stacked and the SDcard to be added:

https://oshpark.com/profiles/mmcgraw74

[wb0gaz]

Thanks so much for the very detailed information and advice!

I just yesterday 12/29 received my GPIB connectors (both male straight and female right angle), and have some ATMEGA644 parts from a project that didn't proceed.

I have a real live HP 9122C floppy drive for which one of the drives appears to work, but it's fragile and ancient, and I'd just like to use it as a reference for undertaking the SS/80 protocol server.

The various protocol documents (linked previously, and downloaded here) look pretty complete but can't guarantee error-free.

Presumably the AR488 code could be used itself to print (to serial port) message exchanges as a debug tool.