Expansion to 1 Megabyte

This expansion allows the use of up to 1 megabyte dRAM in the C16 / +4. If there is no need of compatibility to the expansion of CSORY, up to 4 megabyte are possible.

Because the previous control-logic (TED-Chip) is used, the maximum size of dRAMs, which are usable, is 256k x 1bit (the TED doesn't generate enough refresh cycles for larger dRAMs).

8 of the dRAMs are a bank. All banks are 1-to-1 connected, except /CAS. This signal is generated from the expansion logic. For inactive banks, this signal is high. Only the active bank receives this signal.

The additional dRAMs should be solded on top of the existing ones. Solely the pin /CAS should be stand of from the chip. This signal must be connected with the expansion.

The schematics (inclusive the previous 256k-expansion) are available as postscript, GIF and PNG.

Tips, questions, error per email to :Hendrik.Lipka@gmx.de