#52 - Z80 Machine Code in 20 Minutes (Sinclair ZX Spectrum / Next)

[@Auberge79]

I remember writing BASIC program back in 1994 or around that year. I needed a picture to be moved from memory into screen memory so I user a small machine code program consisting of one command ;-) I simply POKEd those bytes into free part of memory straight from BASIC and used RANDOMIZE USR 'some addredd I don't remember' to make that. The machine code program was LDIR, which moved some bytes of memory (6912, quantity according to one of CPU registers) from starting address indicated in another register to 16384, stated in third register. This was way more fast then PEEKing and POKEing 6912 byted in cycle of BASIC :-)

[@tobobobo5489]

That was actually very helpful. Thank you.

[@Matefromthepast]

Glad you're back!

[@Spriteworx]

Cheers!

[@vmisev]

Ha, take this, Acron fans! No two-pass assembly, no OPT, no […], no P%, just straight machine code running from Basic ;> Just joking, as much as I loved my Spectrum, BBC was amazing machine for the time. Thanks for the video!

[@cprince10]

Great video. If I draw a box using Plot and Draw, how do I fill in the box with colour?

[@lostcarpark]

An interesting video, but the title is a bit misleading, since it doesn't go into very much detail on assembly language or machine code. I know you do state that in the intro. I'd like to see a rapid fire tour of the Z80 instruction set.

[@Hamomim1]

thank you

[@lawrencemanning]

I like your videos but IMO you can and should explain the difference between assembly and machine code very simply: machine code is the binary stream of instructions read and executed by the processor, assembly is a convenient human readable representation of those machine code instructions. An “Assembler” is normally a program, but here you have assembled the assembly stream into machine code, but you’ve still assembled assembly into machine code, just by hand. It’s a bit muddled here. IMO this video would have been clearer and less “fluffy” if you’d sat down with pen, paper and a Z80 instruction table and assembled the program by hand and then loaded it with POKEs. Then you could have talked about other ways to get machine code into the Speccy’s memory. Just trying to help. :)

[@2kBofFun]

Assembly is a half-readable representation, just as garbled as the incredible shitty word mnenomics is. I made a custom assembler that is way more readable, and the instructions in this video would read "A=2", "P(254)=A" and "return"