Issue 2 Test - redcode/ZXSpectrum GitHub Wiki

Author: Weiv
Release date: 2023-06-09
Links: Discord post
Download: tap _^(hosted) - tap _{^{(Discord post)}}

This test shows the difference between Issue 2 and Issue 3 versions of Spectrum 48 and the need for this option in emulators. It sets the state of the input bit EAR = 1 by outputting to the output EAR = 0 and MIC = 1 bits. On Issue 3, in this case, the input EAR bit will be 0, and the program, directly checking the state of port FEh for the given values, will not work on Issue 3, but only on Issue 2 - you can control the position of the X character by pressing any of the outer buttons of the semi-rows (for example, 1-2), but only on Issue 2.

Tested by ZXGuesser

• ZX Spectrum 48K (Issue 2, CPU Zilog Z8400APS, ULA 5C112E): The user can move the X.
• ZX Spectrum 48K (Issue 6A, CPU SGS Z8400AB1): The user cannot move the X.