USR quad modems... (ontopic - really!)

Don THX1138 at
Wed Aug 16 17:14:56 CDT 2006

Roger Merchberger wrote:

[12 modem cards]

> Each "modem section" has:
> an Intel 80C186 (same chip as in the Tandy 2000) - except they're rated 
> for 20Mhz...
> a TI/USR DSP chip, which is prolly useless outside of the intended use

Some of the DSP's are "general purpose" -- external program
store.  However, since you called it a "TI/USR" part, I assume
it has a USR house number on it and, as such, is probably
a masked part.  If so, "useless outside of the intended use"  :>

> 2 each 32Kx8 static ram chips,
> 4 each 128Kx8 static ram chips
> and lots of other 8/16-bit 74-series buffer chips & whanot.
> So, *if* I can get a Dynamic-RAM -> Static RAM converter board designed 
> for the CoCo, I could upgrade 4 CoCo3s to 512K with each modem board.

What's the issue *preventing* this from happening?
(unfamiliar with the internals of a CoCo3)

> Roger "Merch" Merchberger -- SysAdmin, Iceberg Computers
> zmerch at
> What do you do when Life gives you lemons,
> and you don't *like* lemonade?????????????

Use it to flavor your *tea*!
(which is what the 7 - 10G of fresh lemon juice from the
tree in the side yard gets used for each year  :>  OTOH,
finding a suitable use for all the *lime* juice is a bit
harder -- there's only so much guacamole you can eat!
Yet, the juice from the blood orange magically seems to
"disappear"  :>

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