AMSpiriT is an Amstrad CPC emulator currently for Windows, with a strong focus on accuracy. AMSpiriT aims to reproduce as closely as possible the hardware behavior of a real CPC:
- Zilog Z80A processor, coded for T-state operation for increased emulation accuracy. It passes with success dedicated z80 tests (ZEXALL in particular)
- Gate Array (AMSTRAD owner chip), which is emulated at 16 Mhz, for a fine management of memory access, color management, video display and interrupts.
- Video controller (CRTC) in its 4 variants 0, 1, 2 and 4 (Pre-ASIC). It passes the majority of Shaker acid test
- FDC µFD765 floppy disk controller for the management of floppy disk drives (partial emulation)
- Sound generator AY_3_8912
- Intel PPI_8255A chip (used as IO interface with the keyboard, the PSG, the tape reader)
AMSpiriT has been developed from scratch, without any contribution of existing source codes, only based on documentations and technical information freely available on the Internet. In the spirit of an Amstrad CPC, the ergonomics has been thought to be as simple and intuitive as possible.
In its latest versions, AMSpiriT has benefited from the technical assistance of talented demomakers, and in particular of Serge Querné, aka Longshot from LOGON SYSTEM group, who has written an extremely precise description of the CRTC component in his CRTC Compendium. This document comes along with a tool, "Shaker" which serves as an 'acid test, and also demonstrate various algorithms described in this compendium. This major contribution has allowed AMSpiriT to reach a very high degree of precision.
AMSpiriT is still under development. It currently requires a relatively strong PC (a 64 bits Core I5 or equivalent processor is recommended): accuracy has a cost! However, we plan to optimize our emulation core, once we've reached an accuracy level we consider high enough.
Keep in touch & Contribute
Don't hesitate to share your ideas and requests for improvement, report any bug you may encounter. For instance if you find an Amstrad CPC program not working properly with AMSpiriT , please send us a message, with a short description of the issue (what is expected, what was obtained), and ideally a link to a disk (DSK) or a snapshot (SNA) file.
The AMSTRAD CPC is a fabulous 8-bit machine that was largely under-exploited at the time but which still continues to surprise through the superb achievements of its numerous fans around the world. We hope that AMSpiriT will allow many fans of the golden age of family micro-computing to (re)discover the AMSTRAD CPC more than 35 years after its release.
We hope in any case that you will take as much pleasure in using this emulator on a daily basis as we had in developing it.
AMSpiriT is a 'freeware' software. It may be freely distributed for private use but MUST NOT BE USED FOR ADVERTISING OR COMMERCIAL PURPOSES.
ROM images supplied with AMSpiriT are the property of AMSTRAD PLC and Locomotive Software. Amstrad and Locomotive have kindly authorized their distribution in emulators, while keeping the intellectual property.