HP Laserjet ..again....

[Jim Isbell]

As I stated earlier, I have cannibalized three HP laserjet series II 
printers.  In looking over the parts recovered I find that I have three 
(3) totally different memory boards.  

The first is populated with small chips on BOTH sides of the board with 
a total of 128 soldered in chips that appear from their part numbers to 
be 256K memory chips,  That is the number 256 appears within the part 
number.  Now I don't know how wide the buss is but I am assuming 8 bits 
because of its age.  If so this board is a 4 Megabyte  memory board.

The second is only half populated with 16 soldered in chips on one side 
that have the number 1000 in their part number so I am assuming they are 
1meg chips and using the afore mentioned logic I come up with a 
2Megabyte  memory board.

The third is fully populated with 32 socketed chips with the number 1000 
in their part number and that works out to a 4 Megabyte memory board.

Is my logic sound?  

Do I have two 4 meg boards and a 2 meg board?  

What is the largest memory board the Series 2 could hold?

I am assuming that the socketed memory is best because it is easily 
repaired, but are there any problems with the socketed memory having bad 
contacts after time?