One thought occured to me about Ethernet this evening - we will need
to get a block of Ethernet hardware IDs. These will have to be
different for every board, and stored in a PLD or EPROM or EEPROM.
Someone will have to make sure that there are no conflicts in the
addressing scheme. Anybody ever gotten a block of h/w IDs for
ethernet? Got any to spare?
Depending on how bad the ISA bus interface stuff gets, it might be
worth the trouble to just "oem" an ISA card. :-()
I haven't costed the following out, and it occurs in no particular
order, but here goes: a simple on-board 16-bit ethernet would have the
following major items (8-bit might save some glue logic and a SRAM,
but it would not be a major cost savings, so why no throw it in...)
- Controller chip
- ENDEC (might be in the same pack as #1)
- DB-15 connector
- 2 8kx8 or 32kx8 SRAM for packet buffering (some controllers use
DRAM, but most use SRAM)
- 20 MHz oscillator or crystal (maybe)
- PALs (2 or 3) for address decode & buffer arbitration
- LEDs (fuer die blinkenlights :-)
- bus buffers and latches
- pulse xformer for isolation
- serial EEPROM for h/w ethernet ID
to add BNC you add to this:
- coax xcvr chip
- DC_DC converter module
- another pulse xformer or one a whole lotta jumpers
- BNC connector
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