[N8VEM: 19888] Grant Searle's multicomputer : FPGA utilization

[RHKoolaap]

Hi all,

I hope you don't mind me going on yammering about this FPGA configuration.
I do realize I probably have only a small audience.

Anyway, I wanted to implement a video terminal and 2 serial terminals, and
ran into an LE shortage on the chip.
I realized that I only use 32 and 48 k banks in my builds, so I trimmed
down the MMU (sorry James and Will) to use 4 segments of 16 Kb instead of
16 segments of 4kB. This freed up enough LEs to build the above
configuration without any trouble (56 LEs left over)
Changing the code for BIOSes and monitor is trivial.

A while ago I also built Grant's Z80 single board computer which I am now
going to update with a memory manager so I can get CPM3 and MPM to run
properly on that machine too. FPGAs are fun, but not enough soldering :-)

See Ya, RHK

[oscarv]

Hi,

Post by RHKoolaap
I hope you don't mind me going on yammering about this FPGA configuration.
I do realize I probably have only a small audience.

I think you've got a bigger audience than you think. Well, +1 at least. But
from my own, less exciting web page on Grant Searle's multicomp I see
there's a lot of people (200 hits a week) following the project to at least
some extent. FPGA people tend to be the quiet type, perhaps. But not so few
in number :)

Thanks for all the progress! I plan to dive in again after the holidays.

Regards,

Oscar.

[James Moxham]

Re running out of LEs, the cyclone II is pretty full when you add a MMU
and some uarts. Max and I are currently working on a cyclone IV board -
more LEs and only a few dollars more in cost. Enough room for the MMU and
4 uarts and there should be enough room for other things, maybe higher
resolution display.

Boards almost ready for release (version 3).

Cheers, James

Post by RHKoolaap
Hi all,

Post by RHKoolaap
I hope you don't mind me going on yammering about this FPGA
configuration. I do realize I probably have only a small audience.
Anyway, I wanted to implement a video terminal and 2 serial terminals,
and ran into an LE shortage on the chip.

I realized that I only use 32 and 48 k banks in my builds, so I trimmed
down the MMU (sorry James and Will) to use 4 segments of 16 >Kb instead
of 16 segments of 4kB. This freed up enough LEs to build the above
configuration without any trouble (56 LEs left over)
Changing the code for BIOSes and monitor is trivial.

Post by RHKoolaap
A while ago I also built Grant's Z80 single board computer which I am
now going to update with a memory manager so I can get > CPM3 and MPM
to run properly on that machine too. FPGAs are fun, but not enough
soldering :-)
See Ya, RHK
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