[Open-graphics] VGA text mode C version

[Petter Urkedal]

On 2008-07-29, Timothy Normand Miller wrote:
> We have ports defined for a single out-standing read.  That won't work
> for a block of reads, though.  Do we need it for anything?

Considering the VGA code, I can imagine we could use it to have several
glyph transfers in progress if we also make the return pipe long enough
(or transfer to HQ BRAM).  But I'm not suggesting it at this point,
since in addition to the hardware complexity, it may be tricky to
utilize in code.  We can revisit if too much time is wasted waiting for
read data.