Profi interface is memory expansion compatible with russian ZX clones. Then zx ram in range 49152-65535 is pageable on compatible russian ports.
Support 4 memory modes:
1) original ZX128 with all bugs, screen raining(snow effect), contended memory, original ZX128 rom, etc...
2) ZX PROFI 1024kB - compatible memory paging with russian ZX clone ZX PROFI.
3) Pentagon 1024kB - compatible memory paging with russian Pentagon 128kB,512kB and 1024kB (support feature for disable 1024kB and swith to 128kB only)
4) ZS Scorpion 1024kB - compatible mem.paging with russian Scorpion 256kB and 1024kB.
In all this modes you can enable memory contention as on original ZX128 (ram pages 0,2,4,6 and other extended ram pages are fast, ram pages 1,3,5,7 are slow as on ZX128). PROFI interface support feature for disable memory contention - in this FAST mode is slow only first 8kB of both videoram pages 5 and 7, but all other ram pages and I/O ports are fast. In fast mode run some russian demos or games which is normally impossible run on ZX Spectrum. FAST mode enable also run other software from ZX128+2/+3 with critical timing because here is not slow and fast ram pages, full ram is fast, only 8kB from pages 5 and 7 run at original speed. PROFI interface not emulate timing of russian clones, only use compatible memory, ports and accelerate ZX ram/ports.
In all 4 memory modes is possible enable also TR-DOS rom paging - here is modified tr-dos rom with ramdisc support (drives A or D are used as TRD image in 1MB ram). If tr-dos mode is enable then memory access for external devices(on zx bus) is disable. PROFI also support up to 8x DIVIDE memory or MB02 memory 512kB ram + 512kB rom in full configuration. In TR-DOS mode is enable 64kB rom (128editor+48basic=first 32kB rom,gluk monitor+tr-dos rom=second 32kB rom). This rom can run from flash eprom chip 512kB (here is 8x 64kB rom), or from extended ram memory (rom emulation via ram with write protect).
With PROFI is possible configure your ZX as Pentagon 512 with DIVIDE or ZX PROFI 1024 + external divide or ZS SCORPION 256 with MB02+ memory.
Full documentation is here:
http://velesoft.speccy.cz/profi/profi_interface_(5_11_2011)high_priority_techman.zipAfter modify CPLD firmware I can add +2A paging with +3e rom (will run +3e rom with DIVIDE ports), enable multitasking (switch full 128kB ram), etc...
PROFI INTERFACE v3 contain also pins for expansion in future (possibility connect SD card slot, etc...).
May be also add compatible memory with DIVIDE PLUS or DIVMMC 512kB.
PROFI can use own divide memory, but not contain ide ports, then you must connect DIVIDE on ZX bus. Internal DIVIDE,TR-DOS and MB02+ mode can be disable and ZX work with external devices.