RWAP Software

[Vapula]

In the documentation, it's said that a jumper allows to use the DivIDE+ to have ROM0/ROM1 replacement (with ROM0 in 0-15 and ROM1 in 16-31)... But I can only see 3 jumpers :
-CF master
-EEPROM protect
-+3 mode (ROMDIS1/ROMDIS2)

[RWAP]

Yes, there are only 3 jumpers - whereabouts is it in the documentation?

[Vapula]

Implementation of greater ROM/RAM space on DiviDE Plus

DivIDE Plus provides a total of 512K ROM and 512K RAM on the DivIDE Plus in order to enable much improved firmware to be written (this compares to the 8K ROM and 32K RAM available on the original DivIDE Hard Disk Interface).

We decided on 512K as this would allow ramdisk storage and the following additional firmware to be used (as well as the original divIDE firmware):

ResiDOS
CPM22QED MBD (CP/M compatible)
ZXVGS MBD

The DivIDE Plus interface is equipped with 512K SRAM (628512 SMD soldered) and 512K ROM (29F040 PLCC in a socket) with address and data lines corrected, so no dedicated .RAW files are needed to program firmware on another system. The RAM is battery backed.

The scheme chosen mixes MB-02 paging using the Port &17 with DivIDE paging using the &E3 Port. It is compatible with the original 8K firmware without amendment. You will however, need to obtain the ROM reprogramming software from ourselves, rather than use that provided for the original DivIDE, due to different procedures for programming the 29F040 chip than on the 28C64 used by the original DivIDE.

The &E3 Port is untouched. The &17 Port is 8bit, outputs are called Q0..Q7, as follows:

- Q6 and Q7 select the mode (DivIDE, RAM, ROM, reset).
- Q5 must be set to write-enable in RAM and ROM modes.
- Q0..Q4 select the memory banks.

We have also added a jumper to possibly enable extra facilities based on Q4. The jumper is set by default (open) allowing operation as above - however when closed (if Q4 is set, bit 4 of Port &7FFD replaces Q4 which gives the possibility of using custom ROM banks in the 128K Mode (pages 0..15 are used as ROM1, whilst pages 16..31 are used as ROM0 for ZX Spectrum 128K bank-switching).