Apple ][ - IEEE-488 interface (rebuild)?

[r6502]

Hello all,

At the weekend, I'd connected my old 44 year old Apple ][ mainboard back to power, after I cleaned the board and I printed a new holder for the speaker as the foam material that holds the speaker originally became just dust, when you came close to it.

When I switched the power supply on, I heard, after about 36 years of silence, the typical Apple  ][ beep at startup - really amazing, that the board survived under sometimes terrible storage conditions:



During several movements, the number of interface cards, I owned as a student, seems to have dropped and I did not find my original IEEE-488 interface card.

Has anybody tried, to rebuild a copy of this card or has a card for sale? I would be either interested in the PCB files or an existing interface card. This would be interesting for me, as I started at about 1988 to do data acquisition with the Apple ][  and I'd like to continue from that point  ...

Guido

[r6502]

I forgot, the board has an interesting hack:

The original data bus driver 8T28 was replaced with a 74LS254 that has been inserted with an offset into the original socket and the power / control pins have been bent and soldered with some wires to the correct signals:



The data bus driver chip died typically, when you unpaged an interface card while power was still turned on, as you generated a short between D0 and +12V line ...

Guido

[kenzen]

Hello,

I have one inits original packaging.

Let me know,

Kenneth

[MarkF]

No board.
But have schematic and firmware.

[free_electron]

But have schematic and firmware.

that's a printer card, not an IEEE-488 (HPIB / GPIB) board. a GPIB boards needs a upd7210 or TMS9914 or 68488 or HEF47xx controller chip

[free_electron]

https://www.facebook.com/groups/322869066185119/posts/689502486188440/

https://www.applefritter.com/file/apple-ieee-488-interface-schematicjpg
https://mirrors.apple2.org.za/ftp.apple.asimov.net/documentation/hardware/schematics/
https://www.applefritter.com/content/apple-ieee-488-interface-card
https://archive.org/details/aieee488

rom dump attached

[r6502]

Hello all,

I'm just designig a clone of Apple ][ IEEE-488 interface.

The schematic is just ready, see attached PDF file. I'm just working on the PCB and wil upload the design to GitHub, where I just created an account.

BR Guido