Differences

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--- econet [2013-09-22 12:40] – [Model B Upgrade Kit] tim
+++ econet [2015-10-05 15:55] (current) – external edit 127.0.0.1
@@ Line 13: / Line 13: @@
   * File server: Level 1 (very basic) can be run on any BBC with a floppy. Level 2-3 require a second processor (which we have). Archimedes can also act as a file server with some free software.
-===== Model B Upgrade Kit =====
+===== Econet Clock =====
+Option 1: Aftermarket and fully configurable [[http://www.beebshop.co.uk/BMClock.html|clock from BeebMaster]]. £50.
+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, 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 =====
+A passive design, suitable for building into a 5-pin DIN plug, is available:
+http://www.retro-kit.co.uk/page.cfm/content/Passive-Econet-Terminators/
+| 2 | 56R 0.25W resistor |
+| 1 | 220R 0.25W resistor |
+| 2 | 1K 0.25W resistor |
+| 1 | 10uF 16V tantalum capacitor |
+We will probably need to purchase 1/4W resistors as most of our stock is 1/2W.
+We would require two terminators, and consider making a spare.
+===== BBC Master Upgrade Modules =====
+Tim has ordered a [[http://www.cjemicros.co.uk/micros/individual/newprodpages/prodinfo.php?prodcode=ACO-A40ECO5|5-pack of Econet modules]] for BBC Master or Archimedes.
+We will burn our own ANFS EPROMS.
+===== BBC Model B Upgrade Kit =====
 ^ Quantity ^ Part ^ Supplier ^
@@ Line 23: / Line 64: @@
 | 4 | 56K 0.25W 2% resistor | |
 | 4 | 100K 0.25W 10% resistor | |
-| 1 | 22K x8 resistor pack | (to be identified from motherboard/circuit diagram) |
+| 1 | 22K x8 resistor pack | Farnell 9356924 £0.31 |
 | 1 | 2.2nF ceramic capacitor | |
 | 1 | 10nF ceramic capacitor | |
-| 1 | 10uF tanalum capacitor 6.3v | |
+| 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 | (rare item, £3.80 from ebay, £3.17 from digikey) |
+| 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 | (footprint to be identified from Model B motherboard) |
+| 1 | 5-pin DIN PCB socket | 180-degree 5-pin. Appears to be a standard PCB footprint. |
-| 1 | 8-way wafer plug | (looks like header pins and jumpers) |
+| 1 | 8-way wafer plug | 8x2 0.1" header and jumpers (for selecting ID) |
 | 7 | mini-shunts | (to be identified) |