Another CPLD-based ZX Spectrum clone for 48K rubber case with additional features.
Please note: work in progress, not all things implemented at the moment
- Half-sized PCB for 48K rubber case, no case modifications necessary
- Pentagon 128 and Spectrum 128 timings
- Real Z80 in 3.5MHz and 7MHz (no-wait turbo) mode
- 512K RAM
- Kempston Joystick
- Integrated Beta Disk Interface
- Integrated DivMMC
- PAL and RGB video out (Sega Mini-DIN/9 connector)
- Digital video out (EGA header ;))
- Switchable stereo ABC/ACB
- Mono covox
Running Pentagon 128 and Spectrum 128 demos: link
Playing music from SD: link
Sizif have some configurable things which you may change at any moment and that's doesn't require reboot. To do this there is a Magic button: just hold it and press key on keyboard:
| Key | Function |
|---|---|
| 1 | Switch to Pentagon 128 timings (by default) |
| 2 | Switch to Spectrum 128 timings |
| 3 | Switch to 3.5 MHz (normal) mode (by default) |
| 4 | Switch to 7 MHz (turbo) mode |
| 5 | Switch to ABC stereo (by default) |
| 6 | Switch to ACB stereo |
| 9 | Enable all additional features: DivMMC, 512K RAM, Kempston, Covox (by default) |
| 0 | Disable all additional features |
If you press Magic button and didn't change something, standard NMI handler 'll be called on button release.
The board contains 512K RAM. There are two cases how to access it:
- DivMMC enabled (SD card insert) - 128K available via 7FFDh port, 128K via DFFDh and 256K reserved for DivMMC.
- No SD card present - 128K available via 7FFDh and 384K via DFFDh
DivMMC can't be property used with BDI by it's design. So when SD card insert, BDI goes into inactive state.
It's not a bug, it's a feature ;)
- Rev.A - first release. Done. Please see errata (in russian)
- Rev.B - abandoned. Files keep for historical reason.
- Rev.C - BDI has been removed; better video circuit; more capable CPLD. Work in progress.
This work is based on a lot of other projects and would hardly have been successful without them.