An Umbrella Site for Michael Martin's software experiments
Today we wrap up the tour of the ZX Spectrum that we started back in May. At this point the only topic left is the memory handlers on the 128K Spectrum. This didn t see a whole lot of use in the original BASIC tour; the Spectrum s Z80 CPU can only address 64KB of memory at [ ]
I didn t have a great deal of experience with the ZX Spectrum when I first created my Platform Guide for it. After this little tour, I ve gotten my hands much dirtier, seen more capabilities, and worked around more limitations. I have, at this point, earned the right to a few opinions of my own about [ ]
Now that the shooting gallery is done and dusted, it s time to turn to a piece of our initial tour of the ZX Spectrum that has been left untouched: sound. There isn t a whole lot new here compared to what has come before on other platforms, but that in turn means that the core principles [ ]
This week I ll be finishing up the port of my Shooting Gallery Rosetta Stone program to the ZX Spectrum. After last week, the only thing left was shots and the logic surrounding them. This is a feature that needs a lot of work at all levels, from design through implementation through consideration of the top-level [ ]
This week and next we ll work through the port of my shooting gallery Rosetta-stone program to the ZX Spectrum. It s been a long road. We started out knowing how to control text and bitmap output and a decent handle on I/O. From there we designed a reasonably efficient blitting system that operated on 16×16 sprites [ ]
Last week s work got us a functional sprite renderer, but we quickly learned that we don t have enough time to do all our rendering before the next screen is displayed. he targets would flicker or have pieces cut out of them: This is a very interesting glitched frame: only the lower left corner of the [ ]
Last week s article saw us preparing sprite graphics for display on the ZX Spectrum s display screen. This week we ll actually do the rendering, and kick off the shooting gallery project properly: It also turns out that the shooting gallery project doesn t quite exercise all the things we d need from a sprite renderer, so the main [ ]
It s finally time to properly harness the power of the ZX Spectrum s graphics hardware. We ve looked at what BASIC offers us, we ve seen how the system ROM simulates a text mode for us, and we ve implemented graphics primitives on the underlying bitmap ourselves. What we have not done is created a software package that will [ ]
Working on these Spectrum projects has meant more practice with Z80 assembly along with everything else, and while I do think I m basically at parity between Z80 and 6502 now in terms of my skills, the grind of actually doing things with it to get practical experience is still very necessary. Implementing the line-drawing algorithm [ ]
Now then, where were we? Last time, we worked through the many and varied abilities the ZX Spectrum system ROM offers us when we treat the screen as being a text-based terminal. However, as we noted back then, the Spectrum does not in fact have a text mode, and instead provides only a bitmap screen [ ]