= TT_CONST.TXT                                           =
=                                                        =
= Details for constructing a Team Tap compatible joypad  =
= multiplexer. To be read in conjunction with the series =
= of Articles in Atari Computing magazine.               =
=                                                        =
= See also www.ataricomputing.com                        =
=      and www.compsoc.man.ac.uk/~xav                    =
=                                                        =
= This information is provided without any implied or    =
= explicit warranty. Neither Xav nor Atari Computing can =
= be held responsible for any loss or damage caused as a =
= result of work carried out based on these instructions =



= Tracks to Cut =

You will need to cut the copper tracks at the following locations:-

D15, D28
K6 to K15
L6 to L15, L17 to L28
P6, P8, P12, P14
Q7, Q9 to Q11
S29
U2, U4, U12, U14
V29
X2, X4, X7, X9, X12, X14
AA2, AA4, AA7, AA9, AA12, AA14
AD2, AD4, AD7, AD9, AD12, AD14



= Links =

You will need to put metal links between the following holes 
(start:finish) :-

A15:A16
B1:B15, B16:B28
D2:D7
E3:E9
F4:F11, F15:F30
G5:G13, G27:G29
H6:H15, H28:H30
N1:N6, N9:N11
P7:P9, P11:P30
Q1:Q12, Q16:Q17
R2:R8, R22:R23
S1:S14
T4:T10
U8:U29



= PCB Pins =

These are put in with a hot soldering iron from the track side of the 
board. They should also then be soldered into place to ensure a good 
electrical connection:-

A1, A12, A14, A30
H17 to H27
N8, N12, N14
P10
S18 to S22, S24 to S28
W2, W4, W7, W9, W12, W14, W29, W30
X29
Z2, Z4, Z7, Z9, Z12, Z14, Z29, Z30
AA29
AC2, AC4, AC7, AC9, AC12, AC14, AC29, AC30
AD29
AE29
AF2, AF4, AF7, AF9, AF12, AF14, AF29, AF30



= Resistors =

These can be soldered either way round. Note that one resistor is a 
different value to the others. Resistor values are designated by 
coloured stripes, as below:-

1k resistor (Brown|Brown|Red or Brown|Black|Black|Brown) - Q23:Q30
4k7 resistors (Yellow|Purple|Red or Yellow|Purple|Black|Brown) - 
	E1:E2, F1:F3, G1:G4, H1:H5, R12:R13, R14:R15



= Diodes =

Diodes have to go a certain way round. In the following, the first 
hole listed MUST be nearest the end with the stripe:-

R29:T29
V2:V3, V4:V5, V7:V8, V9:V10, V12:V13, V14:V15
Y2:Y3, Y4:Y5, Y7:Y8, Y9:Y10, Y12:Y13, Y14:Y15
AB2:AB3, AB4:AB5, AB7:AB8, AB9:AB10, AB12:AB13, AB14:AB15
AE2:AE3, AE4:AE5, AE7:AE8, AE9:AE10, AE12:AE13, AE14:AE15




= Integrated Circuits =

First solder the sockets into place, then put the chips into the 
sockets as the final step of circuit board construction. The top of 
the chip (and preconstructed sockets) is marked by a scalloped edge, 
or a dot in the top left corner. For both chips in this project, the 
top edge goes towards the top of the board, i.e. row 6 for the 74HC244 
and row 17 for the 74HC154. The latter also comes in two flavours, 
wide or narrow. Details are given for both, but you should only use 
the one that is appropriate to the chip you have:-

74HC244 - J6 to J15 and M6 to M15
74HC154 (Narrow) - J17 to J28 and M17 to M28
47HC154 (Wide) - I17 to I28 and O17 to O28



= Capacitors =

You have two varieties of capacitors. The "ceramic disk" type 
(probably beige and disk-shaped, no markings to indicate polarity) can 
be inserted either way. The "electrolytic" (probably blue or purple, 
looks like a small can with two legs) has to be inserted a particular 
way. In most cases the _negative_ leg is marked by a stripe enclosing 
minus symbols which runs down one side towards the leg in question. 
Common practice, however, marks the positive connection on a circuit 
diagram. In the following, the _positive_ leg is listed first, and the 
_negative_ leg listed second. Please ensure that you get this 
component inserted the correct way round, as they can, and do, 
explode:-

Ceramic disk - C15:E15, C28:E28
Electrolytic - G16:G15



= Plug =

The plug is the male connector which attaches to the EJP. The 
connections below are show as (circuit board:plug) where the second 
number simply represents the corresponding pin on the plug itself. The 
connections to the circuit board are all made indirectly by soldering 
wires to the previously inser
ed PCB pins:-

A1:7, A12:14, A14:13, A30:9
N8:6, N12:11, N14:12
P10:10
S18:4, S19:3, S20:2, S21:1, S22:8



= Socket A =

This is the first of the four team tap EJPs, and is numbered in a 
similar manner to the plug:-

H24:1, S25:4, S26:3, S28:2
W2:10, W4:12, W7:6, W9:11, W12:14, W14:13, W29:8, W30:9
X29:7



= Socket B =

H17:4, H18:3, H19:2, H20:1
Z2:10, Z4:12, Z7:6, Z9:11, Z12:14, Z14:13, Z29:8, Z30:9
AA29:7



= Socket C =

H21:4, H22:3, H23:2, H25:1
AC2:10, AC4:12, AC7:6, AC9:11, AC12:14, AC14:13, AC29:8, AC30:9
AD29:7



= Socket D =

H26:4, H27:3
S24:1, S27:2
AE29:8
AF2:10, AF4:12, AF7:6, AF9:11, AF12:14, AF14:13, AF29:7, AF30:9