tomxp411 wrote: ↑Wed Dec 12, 2018 9:02 pm
You can still transfer programs the old-fashioned way.
That would be loading a TAP file on the PC and hooking my sound card up to the tape input, right? The purpose of the DivMMC is so I don't have to do that.
Sure, I understand that. But what’s the point of having a
Spectrum, and why would you shelve it if it didn’t play ball with the DivMMC? I mean, I have a couple of Spectrums and no DivMMC or any other SD-card interface for them.
tomxp411 wrote: ↑Wed Dec 12, 2018 9:11 pm
Are these all pin compatible with the Z80 the Spectrum 128K +2 ships with? Is there any reason to choose a specific part over another? I'm inclined to grab the 20MHz version, just to have the confidence I've gotten the best quality part I can get.
These are likely CMOS Z80s. Most (all?) original Spectrums came with an NMOS Z80 cpu. If I were you, I’d get the 6 MHz version, or even look online for an old-sock NMOS 4 MHz one. There’s no advantage of getting a higher-clock CPU here.
A 4 MHz NMOS Z80 from Zilog is usually marked Z8400APS, sometimes Z8400A PS (with a space).
You can test if your computer has an NMOS or CMOS Z80 by running this little program:
Code: Select all
10 LET a=4e4
20 READ b: POKE a,b: LET a=a+1
30 GO TO 20
40 DATA 243,1,254,0,237,113,237,120,24,247
After it ends with an “E Out of DATA” message, type
usr4e4 and press Enter.
If the border turns black, your Spectrum has an NMOS Z80; if it remains white, then it’s a CMOS one. My bet it’s the former.