riscy
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misc stuff

To: riscy@pyramid.com
Subject: misc stuff
From: adyer@zarniwoop.chi.il.us (Andrew Dyer)
Date: Wed, 7 Jul 93 22:24 PDT
Reply-to: riscy@pyramid.com
Sender: riscy-request@pyramid.com
other stuff I was thinking about:

- we should reserve an input or two for "manufacturing" jumpers
  so that s/w can run some internal diagnostics and board test stuff

- save a few bits to read the SIMM ID bits, so that s/w can know
  what size DRAM is installed in each bank and 'do the right thing'

- a name for the %^*%(* thing, how about 'Foghorn' (after Foghorn
  Leghorn of course)  If that is too Americentric, feel free to suggest
  something else.  Waldorf Salad? LOAM (Linux on a MIPS)?

- for serial/parallel ports on board, how about a 16C552 - two 
  16550 uarts and a IBM compatible centronics parallel port with 8 bit
  cpu interface.  Made by TI and others.  Also don't forget those
  pesky line interface chips.

- we should come up with a power budget to make sure we won't be 
  overtaxing a standard PC power supply.

- does someone have a heat chamber to test this thing at elevated 
  temperature for a while? It may be GPL h/w, but it doesn't have to
  be flaky...

- think about cooling options for the CPU.  The 33MHz 79R3051E in the MJ
  package runs pretty hot - I'm sure the 40MHz 3081E will really cook,
  especially with more cache on chip.  I would plan on a heat sink and/or fan.
  Don't burn your hands :-)

- for debug, put some headers around the CPU for each pin.  If you only 
  run the local bus to the 3730 it will be hard to hook a logic analyzer to
  either the 3730 or the 3081 without using expensive test clips.

- we should budget for appropriate filters and such for EMI.  If waldorf
  wants to sell this commercially it will have to pass VDE and/or FCC
  (or CISPR) and/or other agency approvals.  Does Waldorf have a 
  site where they can scan the unit? Or are they going to do their own
  layout and only test their version?

I don't want to rain on anybody's parade, but if this is to become a
real product we should pay some attention to these real-world issues
up-front.

 

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