Re: New CBM-II discoveries

From: smf <smf_at_null.net>
Date: Tue, 26 Jun 2018 12:54:01 +0100
Message-ID: <60d32e3e-24fa-2f14-ef2e-f08172a2b654@null.net>
On 26/06/2018 05:46, Steve Gray wrote:
> It looks like we CAN'T replace the 64Kx1 drams with 64Kx8 due to the method used by the EF chip to select individual bits.

You could use faster ram and perform a read, insert the bit and then 
write back the modified byte. You'd probably want to store each plane in 
a 64kx8 dram though, so you'd need 3 copies of that logic.

When outputting you get 8 pixels for each memory read & with this scheme 
you'd continue to do so, if instead you use the extra bits in the ram 
chip for individual planes then you'll need memory that is 8 times faster.
Received on 2018-06-26 14:00:04

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