Yesterday, I found my old Sinclair ZX Spectrum in the attic of my parents' house.
Sweet memories!
It was my second computer (after a ZX81), and I hacked Basic programs into it, hitting the rubber keys one Basic keyword a time.
And this Z80 assembly programming book! OMG. The Z80 is an eight-bit processor. I guess even an Arduino has more power than those home computers from the 1980s.
There was a large array of literature for these early consumer computers, books as well as magazines. Some peeps even disassembled and commented the whole OS ROM in a book! (Yes, back then, the whole OS was baked into read-only memory.)
Disks? No way, you had to save your code on EFFIN' CASSETTE TAPES! I remember the pilot tones the computer send to the cassette tape before sending data. The pilot tone then helped level the playback volume correctly for reading the data back in.
On the pictures, you can see a cable coming out of the case; I soldiered the ends of one side to the mainboard and connected a joystick on the other. Then I wrote my first assembly program that picked up the joystick movements and drew a line on the screen, in the direction I pushed the joystick. But the program was too damn fast; I could barely move the joystick without having the line hit the edge of the screen in an instant.
Boy, assembly language had my deep respect back then!
This reminds me of another story: ZX Basic had a command for drawing a circle; but the code used floating-point arithmetic to calculate the circle. This thing had no floating-point unit; all the floating-point operations were carried out in pure software on the Z80! Eight-bit registers! When you executed the command, you would have to wait for one or two seconds, then the circle was drawn on the screen, slow enough to see the circle building up from 0 to 360 degrees.
Then, someone published a listing with assembly code that built the circle with a super simple calculation of the pixels of an eigth of the circle; then it mirrored the result to the other seven segments. This code drew the circle within the blink of an eye. My jaws dropped to the floor.
But what I remember most from these times of curious exploration of the future was my lasting wish for better, faster, and more sophisticated hardware!
Now look where we are today...
A pretty decent advancement since then, don't you think?
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