Turn your Sinclair ZX Spectrum 16K or 48K into an NTSC ZX Spectrum!
This kit contains a
Genuine "New Old Stock" Ferranti ULA 6C011E-3 as used in original NTSC Spectrums. Coupled with that are a 3.579MHz crystal for the NTSC colour carrier signal, and a
brand new, custom made 14.112MHz crystal as used in the Timex Sinclair TS2068 (the original NTSC Spectrums used a 14.110MHz crystal, but the difference is imperceptible - we had 14.112MHz ones made as these can then be used to repair TS2068 machines).
The replacement NTSC ULA will replace a regular PAL ULA with no modification! If you do not wish to change the crystals, the NTSC ULA will provide a 60Hz display with PAL colour, which is what is called "PAL-60" in modern consoles.
The 14.112MHz crystal does very slightly speed up the Spectrum, but the principle reason for the change is that the 14.000MHz crystal interferes with the display and causes heavy fringing - 14.112MHz crystal resolves this.
Please note stocks of these chips are
very limited and no more stocks of this incredibly rare ULA can now be found.
There may be incompatibilities with certain software because of the 60Hz frame rate, however many games will just run slightly faster! For instance, Auf Weidersehen Monty now moves that little bit quicker (as an example). Regular PAL Games will load perfectly from cassette or mass storage such as DivMMC, but they may not run the same as on a PAL machine.
We are currently experimenting with Issue 3 boards; if your board is different to this please let us know as we can then test it with your issue to make sure of compatibility. These NTSC ULAs predate the last revisions of the 48K Spectrum so compatibility cannot be guaranteed, particularly with Issue 6A boards.