#ZX81 EMULATOR WITH TAPE GENERATOR#
#ZX81 EMULATOR WITH TAPE CODE#

3.5MHz Spectrum running Sinclair BASIC: 15 SecondsД¤. 2MHz Altair running Microsoft BASIC: 14 SecondsДЈ. 1MHz C64 running Microsoft BASIC: 9 SecondsДў. So the ranking (from fastest to slowest) is:ДЎ. So much so that the 64 is 2.8x faster with Microsoft BASIC, and even the Altair with a 2MHz CPU (compared to the Speccy's 3.5) is still a bit faster.

So Microsoft's BASIC seems to be much faster than Spectrum BASIC.

#ZX81 EMULATOR WITH TAPE GENERATOR#

So my simple Prime generator (2-100) runs in: (And I haven't managed to get my Ultimate 64 to actually record to virtual cassette yet. However, it limits what you can do on a real system if you don't have a cassette drive. That's not the end of the world, since it's possible to save snapshots in VICE that contain the entire system state. After that, datasette access in VICE seemed to be broken. The first thing to note is that the ZX emulator doesn't seem to support saving to disk, and VICE was only able to save to tape for me once. So I did some quick tests with FUSE, VICE, and an Altair (The Altairduino) running a Z80. The layout of the character sets and of memory is different, even though the tokens of the older machine are a subset of the newer.

#ZX81 EMULATOR WITH TAPE CODE#

I'd dare imagine that anything that wanted to run within ZX Spectrum BASIC would be little more than a routine that maps the older BASIC code to newer BASIC code and then runs it. The ZX Spectrum doesn't do interlaced output, can't produce a display wider than 32 columns or taller than 24, and when running that emulator doesn't have enough time fully to repaint in a single frame.

Though it is still slower and more limited than the real thing even vertical sync is the programmer's responsibility on a ZX81 so some demos produce interlaced screens, screens without borders, all of the usual demo effects you can get cheaply if you can reset the video fetch pointer at any time, etc. The ZX81 uses the processor to do real-time display fetching, effectively making it unavailable for any other purpose during parts of the display with pixels, so actually that approach to emulation is not as bad as it sounds. The linked one definitely isn't it's an adaptation of the ZX81 ROM to the ZX Spectrum hardware that deploys an interrupt-driven attempt to convert the display of the former to the display of the latter, subject to a whole bunch of special cases and program-specific hacks. You can't have it any other way, just think about it a bit! ok, so, does it mean ZX81 emu is written in ZX BASIC? That is only possible way to make it work in ZX emulator for C64!

Zx81 emulator with tape