26 Nov
2007
26 Nov
'07
9:34 p.m.
On Tue, Nov 27, 2007 at 04:17:26AM -0000, Ensor wrote:
Thinking back to the Rev A and B motherboards, they should have had one 8K
ROM for BASIC and another 8K ROM for the Kernel - that was an inexpensive
size to manufacture in 1982.
....Another was
RAM, the later boards used two 64Kx4 parts instead
of eight 64Kx1, and the very latest ones I saw combined two of the
ROMs (Kernel and BASIC?) into one single chip.
I'd assumed that all 64Cs had the combined Kernel/BASIC ROM, was this not
the case? Likewise, I was under the impression that the move to
a pair of 64K*4 DRAMs
also came about with the advent of the C-64C....
Perhaps it was then, or there was also an Rev E C-64 that was more
integrated, IIRC. If I have it correctly (I have none to check at
the moment), the clock circuit was changed, the RAM and ROM were
changed, and the overall part count dropped, to lower manufacturing
cost. I could also be confusing some of these changes with the C-64C.
-ethan
--
Ethan Dicks, A-333-S Current South Pole Weather at 27-Nov-2007 at 05:30 Z
South Pole Station
PSC 468 Box 400 Temp -29.0 F (-33.9 C) Windchill -53.9 F (-47.7 C)
APO AP 96598 Wind 10.4 kts Grid 8 Barometer 681.3 mb (10579 ft)
Ethan.Dicks at usap.gov http://penguincentral.com/penguincentral.html