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TonyDuell · 1st Apr 2018, 3:40 pm

I avoid the Apple ][ as much as possible, but...

Are you sure it's a serial interface card, because I don't think it is. The ICs are not what I would expect. The Super Serial card had a hardware serial-parallel converter IC on it (I forget if it was a 6551 or a 6850), as opposed to using the Apple's 6502 processor to bit-bang serial data (which is what the original serial card did). But both the original card and the Super Serial card had a couple of PROMs on them containing firmware to drive the card (you could do PR#<slot> where <slot> is the number of the slot the card was put it and all output would go to the serial port, for example). I've seen other Apple ][ serial cards with the 6850, etc, on them, all have firmware PROMs.

I do not see such PROMs or a hardware serial-parallel converter on that board. And there is not enough TTL to do the conversion that way.

The DE9 connector (if it's original to the card) is wrong too. A serial port in those days would be a DB25.

1st Apr 2018, 3:40 pm	#2
TonyDuell Dekatron Join Date: Jun 2015 Location: Biggin Hill, London, UK. Posts: 5,208	Re: Any Apple II Users Here? I avoid the Apple ][ as much as possible, but... Are you sure it's a serial interface card, because I don't think it is. The ICs are not what I would expect. The Super Serial card had a hardware serial-parallel converter IC on it (I forget if it was a 6551 or a 6850), as opposed to using the Apple's 6502 processor to bit-bang serial data (which is what the original serial card did). But both the original card and the Super Serial card had a couple of PROMs on them containing firmware to drive the card (you could do PR#<slot> where <slot> is the number of the slot the card was put it and all output would go to the serial port, for example). I've seen other Apple ][ serial cards with the 6850, etc, on them, all have firmware PROMs. I do not see such PROMs or a hardware serial-parallel converter on that board. And there is not enough TTL to do the conversion that way. The DE9 connector (if it's original to the card) is wrong too. A serial port in those days would be a DB25.