IEEE-488

[doug_in_nc]

You don't see really interesting historical stuff like this, presumably genuine, set of prototypes of a Commodore product come up on ebay vey often. Sadly well beyond what my wife would ever let me pay for it, but really interesting

https://www.ebay.com/itm/255321985950?_ ... %7Ciid%3A1

[orion70]

Wow, very interesting! Museum stuff.
EDIT: take a look at his store...

[doug_in_nc]

If I had a spare few thousand dollars I could go wild in that lot! Wow, he’s selling some really unusual stuff there.

[ral-clan]

Interesting that one of the boards says "VC-40".
I wonder if there was meant to be any connection with the proposed "VIC-40". I doubt it but since the VIC-20 was also called the VC-20 in Germany it makes me wonder:

https://www.floodgap.com/retrobits/ckb/ ... vic40.html

http://www.cbm.sfks.se/tidning/vic-40.html

[Mike]

Interesting that one of the boards says "VC-40". [...]

The edge connector of the unpopulated board has a smaller pin pitch, which suggests it is a prototype for the forthcoming C64, its working title being V(I)C-40.

[garry68]

Wasn't the VC prefix used in germany?

Whare VIC was too close to a bad word

[MrSterlingBS]

Hello, is there a manual of the IEEE-488 cartridge available?

BR
Sven

[srowe]

Hello, is there a manual of the IEEE-488 cartridge available?

Not that I'm aware of. There's nothing really to document, once activated (SYS45065) it passes all operations for devices 4 and above to the IEEE bus rather than the serial bus.

[MrSterlingBS]

Wasn't the VC prefix used in germany?

Whare VIC was too close to a bad word

Yes, this is correct. See my avatar picture.

[MrSterlingBS]

I have another question about the IEEE transmission protocol. How can one byte be transmitted at a time? The IEEE module apparently has its own routines and the floppy 2031 certainly does too. But there are still two VIA 6522s installed in the floppy 2031 that have the bit shift error. So how can 8 bits be transmitted at the same time? That is unclear to me.

[Mike]

how can 8 bits be transmitted at the same time?

IEEE-488/GPIB is 8-bit parallel already to begin with.

...

[brain]

I have another question about the IEEE transmission protocol. How can one byte be transmitted at a time? The IEEE module apparently has its own routines and the floppy 2031 certainly does too. But there are still two VIA 6522s installed in the floppy 2031 that have the bit shift error. So how can 8 bits be transmitted at the same time? That is unclear to me.

And the VIAs have 2 8 bit ports (The xIA-type ICs typically sported 2 or 3 8 bit ports, some handshaking lines, and a synchronous serial shift register, i.e., 6820, 6821, 6822, 6520, 6522, 6523, 6525, 6526)

jim