Euro-Apple Modifications

V. Sullivan

Integrated Circuit Insertion

You are now ready to insert all of the ICs into your Apple board. This is a fairly straight forward task of matching the chip type numbers printed on the board with the type numbers on the chips. There are however a few exceptions, which are noted below. All of the chips have their pins slightly spread and these must be bent carefully in, so that the chips will fit easily in the sockets. If this is not done the pins will bend underneath the chip when it is pushed into the socket and this causes a very hard to find fault. Install the TTL and linear chips first, then the RAMs, ROMs, and 6502 CPU. When working with these last three types of chips you should ground yourself to avoid static damage to the chips. The ROM address numbers are printed on the paper labels on the top. The ROM labeled CGEN is an exception and is explained below. Do not insert it now. Make sure that pin 1 on all chips, as denoted by the notch or dot is next to the pin 1 mark on the board (small white square for each socket).


1) The RAM chips have no numbers on the board. Use the chips labelled 5290J or TMS4116. Do not insert a RAM at location C11.

2) The three 8T97 chips are replaced with either 74LS367 or 54LS367.

3) There are 6 ROM chips labeled HN462732G. These chips are installed as indicated by their address number in row F.

4) There are no chips installed at location A7, C11, J14. The ROM chip labeled D2716D and/or CGEN is the character generator. It is used with the adapter circuit board in the location called 2513 (A-3). Gather together the adaptor board, the 24 pin socket and the 24 pin blue or grey header. If your adaptor board had the holes drilled skip step (a).

a) One of the rows has 3 double pads, drill the holes in this row and also the middle row of the other three rows.

b) Install the 24 pin socket from the blank side of the board. Line up pin 1 of the socket with the dot on the copper side of the board. Solder the socket.

c) Take the 24 pin header and place the surface with the split pin ends flat on the foil side of the board so that the split pins rest on the two rows of pads without the holes drilled out. Note that these two rows of pads are offset just like the split pins.

d) Solder the split pins to the foil from the side. This is difficult to do so take care not to cause solder shorts etc. 7

e) Solder about a foot of #30 wire into each of the three holes next to pins 15, 19 and 22 of the socket. These wires will be referred to as CGEN 15, CGEN 19, CGEN 22 in later steps.

6) Plug the header into the 2513 socket on the board, matching pin i on the CGEN ROM with pin 1 on the socket. If this assembly is too high for your case (later) remove the 2513 socket and solder the header pins right into the holes. Do not do this until all the other mods are done or you will find it awkward to cut some tracks around A1.

7) Connect CGEN 1 9 temporarily to A1-8

You should now have all of the chips inserted into the board.