Profi memory
ZXNet echo conference «real.speccy»
Tell us, who knows how the memory is expanded in Profi: ports, bits.
Andrey.
Andrey Sergaev in his letter to All wrote:
AS> Tell me, who knows how the memory is expanded in Profi: ports,
AS> bits.
bits 0...2 ports #7ffd - 128 kilos
bits 0...2 ports #dffd - over 128 kilos in combination with a port #7ffd
"Andrey Sergaev" <Andrey....@p7.f136.n5011.z2.fidonet.org>
reported/reported the following in the news: >
NA> bits 0...2 of port #7ffd - 128 kilos
NA> bits 0...2 of port #dffd - over 128 kilos in combination with port #7ffd
As for expanding RAM through a memory page with addresses
0xc000..0xffff, this is indeed the case. It is only worth noting that
the unused bits of register 0xdffd should be set to 0,
and that there may be "gaps" in memory - some memory banks may
be physically absent.
In addition to the above, "PROFI" has the ability to connect
additional memory at address 0x4000..0x8000 and disable ROM. This, for the most part, is relevant only for the CP/M mode of computer operation.