Spectrum Computing

Was not sure to put this in the hardware section or here in Programming..

I am writing up my notes for my various projects. I have a list of memory maps - stock 48k, 48k with a printer, 48k with a microdrive (1,2,3,4,5,6,7,8).

This got me thinking, how many other peripherals reserved space in memory, was there ever a list? Because Interface I makes some pretty major changes to facilitate the buffers it uses for the devices. I would assume interface II will also make such changes.

Interface II doesn't make any changes by itself. It's just a series of straight-through-connectors up to the cartridge port and a joystick interface.

Clearly when you stick a cartridge in, it completely replaces the ROM with game code, so nothing of the ordinary Spectrum's Operating System and System Variables exist because it no longer boots from the BASIC ROM. But that's down to the ROM cartridge; not the interface.

The Currah µSpeech does some strange things so it can monitor BASIC variables and a portion of high memory for what to say. I vaguely remember it moves the UDGs down from the top of memory to make room, though I don't know how. I assume it has a bit of ROM with its own functions that cut in when certain parts of the BASIC ROM are called. I don't think it changes anything else in memory, but it does monitor the ROM and RAM for signals to operate.

What got me thinking is peripheral reviews would often make a point of saying 'this device does not use system memory' like it was a special feature / unique selling point. So I figure most peripherals must have had some impact on system memory even if it was minor.

The map gets pretty funky when someone plugs in a cartridge to the Interface II I called that 'Tabula rasa' time.