Hi, I'm new here but have been a lurker for years. I recently received a nice Apple II Plus that had a few cards (including a Videx Videoterm and MS language card), and I just noticed this logic board's part number is not documented online: 820-0044-00
The only 820-0044-XX revisions I can find info on are: 820-0044-01, 820-0044-C, and 820-0044-D, with the main source being the defacto The Apple II Circuit Description:
RFI-The RFI mother boards are identified by the part number 820-0044-XX.The "XX" is the revision and to date (July 1982) the latest revision is "D." Therehave been previous revisions of "01" and "C." The part number is found near the F1location (left edge of board). The differences between RFI revisions involve locationsand quantities of ferrite beads and other changes intended to further suppress RFIemissions. To date there have been no functional circuit changes between RFI revi-sions. We refer to all RFI mother boards (through revision D) as simply "RFI."
Does anyone have any information on this revision? Check out the pictures to see if I'm missing anything.
It might be just a Rev.0 RFI motherboard. Unfortunately that doesn't make it as collectable as the non-RFI Rev.0, which sold for over $6,400 on eBay last week, even though yours could be rarer. What is on the label on the back of the case?
As far as the "Apple II Circuit Description" book is concerned - I think it is not surprising in 1983 to be unaware of a particular revision.
There were definitely more revisions than what that book mentions. That one is new enough it doesn't have the RAM blocks, but based on the keyboard it probably isn't one of the later ones like D. Its probably somewhere between 4-7. I've seen some boards with the revision put on with a marker over what is etched on the PCB.
Edit -- I could be wrong, it could be later than 7 but less than D... I'm wondering if the "A" in marker near the number in one of those pics is significant.
The RFI 820-0044-C and RFI 820-0044-D have different traces near the F1 position. This 820-0044-00 looks much closer to the 820-0044-01, which makes me think that it's indeed the very first RFI motherboard:
Here are the C and D:
Great info here all.
While we're at it, does anyone recognize the blue PCB inline with the keyboard? One of my II Plusses has it, I know it has a pad marked shift presumably to wire to the paddle socket for the shift key mod, but it also has that other wire and pot as pitcured in the OP.
I'm thinking CVT is probably right... probably the firstr RFI revision board.
Nice, I haven't seen one of those in years. At one time where were a couple of different things like that on the market. Porbalby the biggest competitor was the Videx Enhancer II which proviced a bunch more functionality.
Awesome, thank you for helping me solve that mystery! Hopefully OP finds that info of some use too (TY OP for letting me sidetrack this for a moment).
Thanks all for the info! I was also wondering about the REPEATERRRR board, so I'm happy to read more about that.
A few things to note that I'm wondering if anyone has thoughts on:
Well, the case serial number and the date code on the motherboard puts you really close to:
from this Apple II registry: https://diskpreservation.com/?pg=apple_registry