REC 8726 (RAM Expansion Controller) reference

REC register set:
    7 6 5 4 3 2 1 0
$DF00 (R)SR IRQ EOB Verify Size Version
$DF01 (R/W)CR Execute reserved ² Load FF00 reserved ² Transfer Type
$DF02 (R/W)  C64/C128 start address (A7-A0)
$DF03 (R/W)  C64/C128 start address (A15-A8)
$DF04 (R/W)  REU start address (A7-A0)
$DF05 (R/W)  REU start address (A15-A8)
$DF06 (R/W)  unused ¹ REU start address (A18-A16)
$DF07 (R/W)  Transfer length (D7-D0)
$DF08 (R/W)  Transfer length (D15-D8)
$DF09 (R/W)  IRQE EOBE VerifyE unused ¹
$DF0A (R/W)ACR C64 fixed REU fixed unused ¹

¹ - Unused bits read back 1
² - Reserved bits read back 0


Transfer Types:
0 C64 to REU
1 REU to C64
2 Swap
3 Verify


© 2010 Graham