Amstrad CPC Z80 Question

[Blindseer42]

The Z80 has more instructions then the 6502, runs at 4Mhz and yet there are no provisions for Division and Multiplication, I have to add them manually and add the code to get them to work? 

 

Why is this? Sample code is here

 

 

[ChildOfCv]

Most early processors had no multiply or divide instruction.

 

However, your multiply and divide routines are completely inefficient.  You should look for Z80 multiply and divide routines that use efficient shift and add/subtract methods.

[Blindseer42]

1 hour ago, ChildOfCv said:

Most early processors had no multiply or divide instruction.

 

However, your multiply and divide routines are completely inefficient.  You should look for Z80 multiply and divide routines that use efficient shift and add/subtract methods.

I'm using the site's suggested routines for now. Z80 is easier for me then 6502

[ChildOfCv]

2 hours ago, Blindseer42 said:

I'm using the site's suggested routines for now. Z80 is easier for me then 6502

I'm not sure what 6502 has to do with this...

 

I suggested looking for Z80 functions that do multiply and divide efficiently.  But if you're just trying to learn Z80 machine code using examples, then rock on.