From its design/specs, it looks to have very similar capabilities as a Sinclair ZX80/ZX81. And the lesser-known Jupiter Ace.
Read: ~3/4 of the time the CPU cycles through some tightly-coded ROM software, and character data from ROM + a bit of circuitry generates the monochrome video signal.
Roughly ~1/4 of the time (vblank) the CPU can work on user programs.
Given the constraints of composite video timing, the Galaksija must be doing this in similar fashion. So with a Z80 at 3MHz it would perform as if at ~0.8MHz. Slow (even by those days' standards!), but useable.
ZX81 is rather flexible in how it produces graphics (esp. with 16KB RAM). And has a "FAST" mode in which the video generation is skipped, giving full CPU speed @ the cost of a blank screen. Dunno if Galaksija can do this.
ZX Spectrum added dedicated video hardware (no CPU work needed to generate image), color, sound, and more extensive BASIC. So from programmer's perspective, a very different beast.
Disclaimer: I'm one of the very few people who re-implemented the ZX81's "ULA" chip (a kind of semi-custom gate array) in a CPLD. So I know a 'little' about how this works. :-)
If you want more info just ask. Not familiar with the Galaksija design though.
Read: ~3/4 of the time the CPU cycles through some tightly-coded ROM software, and character data from ROM + a bit of circuitry generates the monochrome video signal.
Roughly ~1/4 of the time (vblank) the CPU can work on user programs.
Given the constraints of composite video timing, the Galaksija must be doing this in similar fashion. So with a Z80 at 3MHz it would perform as if at ~0.8MHz. Slow (even by those days' standards!), but useable.
ZX81 is rather flexible in how it produces graphics (esp. with 16KB RAM). And has a "FAST" mode in which the video generation is skipped, giving full CPU speed @ the cost of a blank screen. Dunno if Galaksija can do this.
ZX Spectrum added dedicated video hardware (no CPU work needed to generate image), color, sound, and more extensive BASIC. So from programmer's perspective, a very different beast.
Disclaimer: I'm one of the very few people who re-implemented the ZX81's "ULA" chip (a kind of semi-custom gate array) in a CPLD. So I know a 'little' about how this works. :-)
If you want more info just ask. Not familiar with the Galaksija design though.