SP-2-ZX81, the new ZX81-emulator for the 48K ZX Spectrum

Emulator and emulator development specific topics
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dr beep
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SP-2-ZX81, the new ZX81-emulator for the 48K ZX Spectrum

Post by dr beep »

This is the official release of my NEW ZX81 EMULATOR for the 48K ZX Spectrum.
Fully software and much faster than my emulator from 1997.
The old emulator is also included.
https://www.mediafire.com/file/oiejfzmj ... X.zip/file
dr beep
Posts: 1303
Joined: Thu Jun 16, 2011 8:35 am
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Re: SP-2-ZX81, the new ZX81-emulator for the 48K ZX Spectrum

Post by dr beep »

UPDATED VERSION:

EDIT: VERSION 1.01 LACKED THE SPEEDFINDUPDATE, REPAIR FOLLOWED IN V1.02

Release of version 1.01

Bugfix:
Bug LD A,R, my opcode source missed this opcode but some games use this as some kind of RND

Convenience fix:
DEBOUNCE set to 10, a bit slower as request

Extra options:
Added CHROMA CHR-support.

Extra tools outside the emulator:
Converter for CHR-files
Converter .P to TAP-files

1 CHROMA game added

The emulator:
{REPLACED BY 1.03}

EDIT: BUGFIX DELAYFINDER V1.02
Last edited by dr beep on Wed May 06, 2020 7:14 pm, edited 1 time in total.
dr beep
Posts: 1303
Joined: Thu Jun 16, 2011 8:35 am
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Re: SP-2-ZX81, the new ZX81-emulator for the 48K ZX Spectrum

Post by dr beep »

Version 1.03

Bug LD A,R was NOT fixed in 1.02

Added tooling to convert CHR and P file directly in 1 TAP-file
2020 SP-2-ZX81_v103.zip
(96.18 KiB) Downloaded 192 times
dr beep
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Re: SP-2-ZX81, the new ZX81-emulator for the 48K ZX Spectrum

Post by dr beep »

I am working on speeding up by some percentages.
I don’t use IX so I am changing JP MAIN into JP (IX) on all opcodes. This gives some speedup.
Also room left in range 8K-16K so I migh5 move the screenroutine there and make some speed there.
dr beep
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Re: SP-2-ZX81, the new ZX81-emulator for the 48K ZX Spectrum

Post by dr beep »

I coded a whole new version to add speed to the emulation.
On 3 points speed could be won:

1) When each opcode would have its own mainroutine 10 tstates per opcode should be won.
The intruptroutine needed to be called anytime to get this working and all opcodes would get extra code.

2) Split A from F can speed up over 40 opcodes in the emulation from 4 up to 8 tstates

3) Mainroutine ED and FD inside own table would win 4 tstates on both opcodes with prefixes.

All is added in the version 2.00 and some bugs are fixed.
Also FULL SOURCE now added.

The memory of the 48K ZX Spectrum is now filled. No room left for other options or speeding up.

The full emulator:
SP2ZX81-20.zip
(254.24 KiB) Downloaded 206 times
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kokkiklhs
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Re: SP-2-ZX81, the new ZX81-emulator for the 48K ZX Spectrum

Post by kokkiklhs »

This is great, I hadn't visited the forum for a while and it was a precious gift for me to see your new emulator finished!
I just tested it on real Speccy, it works fine!!! Next step will be to try it on my Enterprise 128, using the excellent software-only Speccy emulator! I'm pretty sure it will also work there! ;)
The manual is a very nice and useful addition!
You are surely my ZX81 hero dr beep, thank you, thank you, THANK YOU!!!
8-)
dr beep
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Joined: Thu Jun 16, 2011 8:35 am
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Re: SP-2-ZX81, the new ZX81-emulator for the 48K ZX Spectrum

Post by dr beep »

Well,

A quick scan on WIKIPEDIA tells me that on a ENTERPRISE a full speed ZX81 emulator must be possible, like the SAM-coupe or a ZX Spectrum 128 with interface. Bankswitching must be possible to set memory in order and update screen during intrupt.




Johan "Dr Beep" Koelman
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