The Spectrum Emulator is alternative FPGA config which emulates both the ZX Spectrum 48K and Spectrum 128 (in a non-precise manner).
Limitations:
There are two parts to the installation:
When the file menu loads, select a .sna file with the cursor keys and press Enter to load it. (For best compatibility, Spectrum 48 sna files use the original Spectrum 48 ROM file, and Spectrum 128 use the newer ROM.) Note: Only the first 44 files and folders in each directory are listed. You can also press B to go to the Spectrum 128 front end (BASIC), Shift and 1, 2 or 3 to restart the FPGA from another config slot or Shift+V to switch VGA to 50Hz (no effect on PAL/NTSC mode)
During emulation, press Escape to go back to the .sna loader (F1-F12 adjusts the speed for versions of the V6Z80P that cannot directly control the CPU clock)
A Kempston type joystick is supported in Joy port 1.
The 40 key Spectrum keyboard is emulated. Also the PC backspace and cursor keys are mapped onto the Spectrum's matrix (these keys casue SHIFT to be held at the same time).
On boot, the ROM in the FPGA loads the file “bootcode.exe” from the SPECTRUM dir at $800. If this file is missing, an error is shown (at this point you can download a bootcode.exe file serially if desired).
The bootcode looks for an ID string in memory, if it is not found it loads the Spectrum 128 and Spectrum 48 ROMs, initializes the keyboard etc. The file menu is then shown. The bootcode can be changed to create a more advanced front end. The memory area $800-$3fff is free for this use.