Differences

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--- econet [2013-10-03 13:16] – [Terminators] tim
+++ econet [2013-10-17 19:41] – [BBC Model B Upgrade Kit] tim
@@ Line 19: / Line 19: @@
 Option 2: [[http://bbcdocs.timhawes.com/filebase/econet/hub.gif|Econet hub circuit]] from Mark Usher, incorporating workstation junction and terminators. Clock duty cycle is fixed at 50%.
-Option 3: Build our own clock with an ATtiny and a differential driver IC. Would need to consider the maximum speed at which the ATtiny could maintain a clean clock signal. If we take this option, I would suggest building it into a hub unit with 4-5 sockets (2 passthrough and 2-3 workstation), but keep the terminators as separate plug-in components.
+Option 3: Build our own clock with an ATtiny and a differential driver IC. Would need to consider the maximum speed at which the ATtiny could maintain a clean clock signal. If we take this option, Tim suggests building it into a hub unit with 4-5 sockets (2 passthrough and 2-3 workstation), but keep the terminators as separate plug-in components.
+===== Cables =====
+-pin Male to 5-pin Male. One is required for each workstation to connect to a junction, and one between each junction.
+Tim recommends buying some cheap ready-made cables from ebay (usually sold for audio or MIDI applications). Make sure that the cables have all 5 pins fully-connected.
+We can make our own cable if we need to link further than 5M (e.g. across the length of the lab).
+We should also consider whether to span between G1 and G8. It should be possible to use the spare CAT5 port next to galahad and patch that into G8.
+Tim has a stock of 6-core shielded cable that would be suitable for custom cables.
 ===== Terminators =====
@@ Line 57: / Line 69: @@
 | 1 | 10uF tantalum capacitor 6.3v | |
 | 1 | 100pF ceramic capacitor | |
-| 1 | 74LS74 | Farnell 1105907 £0.51 |
+| 1 | 74LS74 | Ordered from Mouser |
-| 1 | 74LS132 | Farnell 1470858 £0.54 |
+| 1 | 74LS132 | Ordered from Mouser |
-| 1 | 74LS244 | Farnell 1739688 £0.72 |
+| 1 | 74LS244 | Ordered from Mouser |
-| 1 | 75159 | (£3.80 from ebay, £3.17 from digikey, £3.13 from mouser) |
+| 1 | 75159 | Ordered from Mouser |
 | 1 | 68B54 | (obsolete item, ordered from ebay by Al) |
-| 2 | LM319 | Farnell 1094247 £0.80 each (until stock exhausted, then 9487581 £2.15 each) |
+| 2 | LM319 | Ordered from Mouser |
-| 1 | 74LS163 | Farnell 1470787 £0.66 |
+| 1 | 74LS163 | Ordered from Mouser |
-| 1 | 74LS123 | Farnell 1470902 £0.38 |
+| 1 | 74LS123 | Ordered from Mouser |
 | 1 | 2764 EPROM | (will use old EPROM from Hacklab stock) |
 | 1 | 5-pin DIN PCB socket | 180-degree 5-pin. Appears to be a standard PCB footprint. |