Z80 CPU Microprocessor Instant Reference Card (1981) [pdf]
ballyalley.com
ballyalley.com
Having said that, I'm not sure how actually-useful this particular reference card is: huge hex conversion table, but no instruction timing chart?
Anyway... pure nostalgia caused me to go through an old Z80 assembly book just now ("Advanced Spectrum Machine Language"), and I found some code I wrote a good 35 years or so ago: https://ibb.co/fvqtwkQ
This was printed on thermal paper (not sure about the printer model: I don't think it was the original ZX Printer, as that used differently-sized paper), so sort-of impressed it survived that long (most printouts I had from that time long faded). As to why I wrote the code or what it does: I think it was to create an animated tape loading screen, but...
The Z80 (designed by Federico Faggin and Masatoshi Shima - two of the 8080 designers) was designed to be binary compatible with the 8080 but more capable - so the architectures would have atleast started out very close.
> The Z80 CPU can execute 158 different instruction types including all 78 of the 8080A CPU
Instruction timings are in the pink table on the left-hand side. For example, `ADC HL, BC; ED4A; H15` means that the instruction affects the flags as in row H and takes 15 cycles to execute.
has a few more charts from the same publisher.
https://worldofspectrum.org/ZXBasicManual/zxmanappa.html
For me, programming mostly involved typing in decimal opcodes using that as a reference. I did own an assembler at some point, but loading it from cassette got old quickly, especially as running my code would usually crash and reset the machine.
https://photos.app.goo.gl/6uoeB82vA9vKzjvbA
I have had this for a very long time.
[0] https://www.smspower.org/uploads/Development/z80-documented....
How times change.
Keep in mind that these are things that people would set out to buy on their own. Plastic, or at least durability, is something the consumer would look for. They aren't something thrown into the box with an IC, where the vendor would do everything they could to reduce the cost.