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