I have an original Apple ][ with the following characteristics:
- Revision 0 board
- Handwritten number on board: 4224
- Dark-green slots w/mounting tabs
- Serial number on case: 3929
- Fully-raised power light
When is this unit likely to have been manufactured?
1979. There may also be a corroborating date stamped on the inside of the plastic case, on one of the walls.
I'll have to check for the date-stamp on Monday. '79 seems a tad late for a Rev 0 though, plus I thought the motherboard-numbering had changed to 79xx by then. *shrug*
I would wager the system was made April-May 1978. Reason is that around 2000 complete rev.0 systems were made by end of 1977 (based on some serial numbers I've seen on systems delivered around the new year mark) and in July 1978 they switched over to the rev.1 boards after producing around 5700 total rev.0s.
There may not be a date stamp on the inside of the case. If not, a good way to estimate the date is looking for the most recent 78XX date stamp on all of the ICs, because the system was likely assembled that week or very shortly after. Keep in mind several of the original ICs may have gone bad over the years and been swapped out with later dated ones...but since for sure the system was made in 1978 you can ignore any date stamps from 1979 onward (or for that matter any 78XX codes after July.)
Howie
1977 or 1978. The old-style keyboard should have been phased-out by 1979. I've got a II Plus with a manufacture date on the motherboard of 7905, and it has the new style keyboard, along with a revision 4 motherboard.
Are you sure your 7905 motherboard is a rev.4? I ask because I have a 7905 rev.3 motherboard. Are the Memory Select blocks removable or soldered in place? (that's the obvious difference between rev.3 and 4). It's also interesting that your machine is a II Plus, since I really thought motherboards in the very first II Plus systems had 7920 or 7921 date codes (and were rev.3).
Again, just curious.
Howie
Although actually the definitive way to tell is, of course, to remove the 6502 and see if the board has -03 or -04 printed beneath it
Howie
I might have the revision number mixed up. The memory select blocks are all removable. (16k, of course)
I have a feeling that this motherboard was originally "destined" to be an Apple II system, but fate would have it stuffed with Apple II Plus chips. They are dated from the 80s. That and a few other clues gave me the impression that the motherboard in my II Plus was manufactured many months before it was eventually stuffed with chips and placed into a II Plus case.
(For clarity, I am not implying that it was a standard II that was later upgraded to a II Plus.)
Spring or Summer of '78 - Check date codes on chips for more clues. Though some chips may have been replaced through the years (particularly DRAM), there should be a general theme indicating approximate time when the last chips were made, just prior to shipment to Apple's contract manufacturer. Though it doesn't really matter, I'm assuming that they still were using contract manufacturers to make up PCBs at this early date. The date codes are usually printed in form of YYXX when YY = year and XX = week of year. IE 7816 = 16th week of 1978. Also the keyboard probably has a manufacturing date stamped on the back of the PCB. Add a week or month after the latest date to get an approximate manufacturing date.
let me know what you find.
Regards,
Mike W.