mcmahan@netcom.UUCP (Dave Mc Mahan) (05/03/90)
Now that the A3000 is upon us, can anyone tell me what the E-clock rate is? Also, is that the signal being fed to the CIA chips to provide clock pulses, or is the CIA chip clock something else again? -dave
grr@cbmvax.commodore.com (George Robbins) (05/03/90)
In article <11577@netcom.UUCP> mcmahan@netcom.UUCP (Dave Mc Mahan) writes: > Now that the A3000 is upon us, can anyone tell me what the E-clock rate is? > Also, is that the signal being fed to the CIA chips to provide clock pulses, > or is the CIA chip clock something else again? The E-clock is the same old 715Khz that it's always been, however it's being generated by the bus control logic instead of the processor chip (no e-clock on the 030). This preserves software compatibility at the expense of a few wait states when doing 8520 accesses. -- George Robbins - now working for, uucp: {uunet|pyramid|rutgers}!cbmvax!grr but no way officially representing: domain: grr@cbmvax.commodore.com Commodore, Engineering Department phone: 215-431-9349 (only by moonlite)
daveh@cbmvax.commodore.com (Dave Haynie) (05/03/90)
In article <11577@netcom.UUCP> mcmahan@netcom.UUCP (Dave Mc Mahan) writes: >Now that the A3000 is upon us, can anyone tell me what the E-clock rate is? >Also, is that the signal being fed to the CIA chips to provide clock pulses, >or is the CIA chip clock something else again? The E clock rate is the same, mainly for compatibility reasons. The E clock, such as it is, remains part of the expansion bus specification as well. The CIA chips can use the E clock as the timebase for some of their counters, though each gets fed an alternate timebase as well; one gets the horizontal sync line, the other gets the 50Hz/60Hz line frequency. There are no longer actual signals corresponding to the 68000 /VPA or /VMA lines anywhere in the 3000; the CIAs are driven directly by the Fat Gary chip. > -dave -- Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests" {uunet|pyramid|rutgers}!cbmvax!daveh PLINK: hazy BIX: hazy "I have been given the freedom to do as I see fit" -REM