* Button triggers NMI
* 8K ROM data has 4 regions. There is an NMI vector at offsets &0066, &0866, &1066 and &1866 within the ROM data. This suggests each of the 4 regions is selectable and mappable into the range &0000-&7ff.
What is not clear is that when the chosen region is mapped into the Z80 memory space if the region in &0000-&7ff is repeated through to the end of &3fff.
* Region 0 appears to be is for saving "DraySoftONE". * Region 1 appears to be is for loading "DraySoftONE" * Region 2 appears to be saving is for saving "DraysoftTWODraySoftTWO". * Region 3 appears to be is for loading "DraysoftTWODraySoftTWO"
It seems that the "1/2" switch on the PCB chooses between which 4k (assumption it is connected to A12 of the EPROM), then the "load/save" switch chooses between the 2k within that 4k (assumption it is connected to A11 of the EPROM).
* The filenames written into Dissassembly of the directory are there to indicate there is Disc Wizard data presentcode indicates it uses direct FDC disc access for loading/saving. The filenames contain lower case characters so can't A disc must be run from BASIC - in the files will not be found. The files are not correctly setup anyway, they lack drive when the cluster values, extents and other data that correctly describe a true filebutton is pressed.
* Dissassembly of the code indicates it uses direct FDC disc access for loading/saving. * Dissassembly of the code indicates it uses an I/O port &f0e0, and sends the data 0,1,2 or 3. It is not clear the function how this port is decoded and which address lines or the exact decoding data lines are important. Bit 0 of the data written to this portpotr appears to be set (1) to enable the ROM, and reset (0) to disable it. Function of the other bits are not yet known. Bits 2..7 don't seem to be used?
* It is restricted to loading/saving using DATA format disc. It uses sectors &c1-&c8 and reads/writes this entire range on each track in a multi-sector operation. DATA format has 512 bytes per sector, so sectors &c1-&c8 is 4K. So it reads 4K from each track.
* Disc must be pre-formatted to DATAformat.
* You can't use it with a disc with existing files because it writes data at specific places on the disc. It does write a dummy directory entry to indicate it's files are there is data on there, but the device has the loader code in it, so you must use the device (or a seperate separate program) to load them back.
* Track 1 is used for temporary storage (it saves the screen here and reloads it after).
* It writes a dummy directory to track 0.
* it writes 2 to f0e0 to disable it's own It appears the RAM exists under the Disc Wizard ROM and 3 to f0e0 to enable when it's own ROMenabled. Bit 0 of The code assumes it can use the data appears stack to store the current register settings at the point the NMI is triggered, and this may be set (1) to enable located under the Disc Wizard ROM, and reset (0) to disable it. Function of bit 1 is not yet known. Unanswered questions:* What happens It appears that when a the CPC is reset is triggered? Assumption, it disables it's ROM.* What is the decoding of the I/O port?* Can the Disc Wizard ROM be paged in and read through software? Yes it seems, it does it in order to save the memory. But is it visible only after NMI like multiface?* Can you have other files on the disc at the same time or is it a special disc format? NO it seemsdisabled.
== Pictures ==