Forwarded message from Gregg C Levine <[EMAIL PROTECTED]>:
>Right John. The I8080 in its original form ran at 800Khz, then when it
>finally ran out, so to speak, they were up to about 4Mhz, but only in
>small lots. The rest of what you are writing about, you are quite
>correct.
IIRC the 8080 usually clocked at 2MHz for most of it's life;
The 800K number may be more of KOPS rather than clock rate
(though even that seems high based on my recollection).
The 8080 was a *dynamic* chip so you couldn't single-step it
by stopping the clock. The Z-80 used static logic so it
could be dealt with that way- and the Z-80s were able to
be clocked up to 4MHz almost right away.
(The Z-80 is not completely dead, BTW; The Z-800 chip still
exists, IIRC, and uses some cool tricks to handle more RAM.)
The 8085 actually jumped past 4MHz (again, from memory, I
once had an S-100 system w/ the CompuPro 85/88 CPU card)
but I don't remember the final rate. There was some odd
stuff to the 8085 that made it's instruction set incompatible
w/ the Z-80.
I don't know if any folks here remember that DRI had a PL/I
for CP/M-80- Though I tended to use BDS C and then Aztec C.
I even wrote a tool that'd make a tar floppy so we could pass
files to a Xenix system.
--
John R. Campbell Speaker to Machines [EMAIL PROTECTED]
- As a SysAdmin, yes, I CAN read your e-mail, but I DON'T get that bored!
"It is impossible for ANY man to learn about impotence the hard way." - me
"ZIF is not a desirable trait when selecting a spouse." - me
