A very simple Z80 computer often consists of just a CPU, 8KB of ROM, 8KB of RAM, and a UART. By writing a small monitor program (in Z80 assembly), you can control the computer via a terminal on your PC [4†L38-L42].
The ZX Spectrum ULA is not a "graphics chip" like the VIC-II or the TMS9918. It is a that just barely worked.
The ULA decoded I/O addresses. It listened to ports 0xFE (254 decimal).
🛠️ Modern Microcomputer Engineering: Recreating the ULA
+---------------------------------------------+ | FERRANTI ULA | | | CPU <---> System Clock | Video Timing | DRAM Refresh | <---> Display (TV) | Memory Contention | Cassette & Audio | +---------------------------------------------+ 1. Master Video Timing Generator
If the ULA died, the computer was e-waste. This was the antithesis of the Apple II (which had socketed TTL chips). This trade-off (unrepairable vs. affordable) defined the British home computer boom.
The ZX Spectrum went through several ULA revisions during its production life. The original ULA was the Ferranti 5C102, which contained the keyboard fault and was later replaced by the 5C112. Later 48K models used the Ferranti 6C001, while the Spectrum 128 and +2 models used the Ferranti 7K010E (later labelled Amstrad 40056). Amstrad’s later +2A, +3 and +3B models abandoned the Ferranti design entirely in favour of a different gate array.
Spectrum Ula- How To Design A Microcomputer -zx Design Retro Computer- !!exclusive!! - The Zx
A very simple Z80 computer often consists of just a CPU, 8KB of ROM, 8KB of RAM, and a UART. By writing a small monitor program (in Z80 assembly), you can control the computer via a terminal on your PC [4†L38-L42].
The ZX Spectrum ULA is not a "graphics chip" like the VIC-II or the TMS9918. It is a that just barely worked.
The ULA decoded I/O addresses. It listened to ports 0xFE (254 decimal).
🛠️ Modern Microcomputer Engineering: Recreating the ULA
+---------------------------------------------+ | FERRANTI ULA | | | CPU <---> System Clock | Video Timing | DRAM Refresh | <---> Display (TV) | Memory Contention | Cassette & Audio | +---------------------------------------------+ 1. Master Video Timing Generator
If the ULA died, the computer was e-waste. This was the antithesis of the Apple II (which had socketed TTL chips). This trade-off (unrepairable vs. affordable) defined the British home computer boom.
The ZX Spectrum went through several ULA revisions during its production life. The original ULA was the Ferranti 5C102, which contained the keyboard fault and was later replaced by the 5C112. Later 48K models used the Ferranti 6C001, while the Spectrum 128 and +2 models used the Ferranti 7K010E (later labelled Amstrad 40056). Amstrad’s later +2A, +3 and +3B models abandoned the Ferranti design entirely in favour of a different gate array.