Re: 65c02 in Apple][

["Bill Garber" <willy46pa@comcast DOT net>]

"Robert Steinmetz" <not-rsteinmetz@mindspring.com> wrote in
message 40A795A3.4000801@mindspring.com">news:40A795A3.4000801@mindspring.com...
: Robert Steinmetz wrote:
:
: > Vince Briel wrote:
: >
: >>> The real reason for this is to use a CFFA card in this
machine,
: >>> which requires  65c02 but its not working correctly (yet)
: >>
: >> I've worked with Rich Dreher on that problem for a while and
I've also
: >> installed a Rockwell 65C02 in my IIplus with weird results.
: >> It seems to work for a few seconds then looses the ability
to do
: >> prodos commands. I've read old articles relating to issues
with a
: >> 65C02 in a IIplus and the problem appears to be a memory
timing issue.
: >> It may be possible to replace the 74LS257's at locations B6
: >> and B7 on the main board with a faster version like a HCT
series. I
: >> haven't tried this yet but I plan to within the next couple
of
: >> weeks.
: >>
: >> Vince
: >>
: >> --
: >> Replica I
: >> The Apple I clone
: >>
: >>
http://www.applefritter.com/apple1/members/replica1/index.htm
: >>
: >
: > Yes, the results I'm getting seem sort of consistently,
inconsistent.
: >
: > I also tried a Zip Chip, with almost the same results.
: >
: Sorry for replying to my own post.
:
: I forgot to mention I have been able to boot Prodos 2.0.x from
a
: Disk][ in my Apple][ with the 65c02 installed.
:
: I think possibly the problem may lie in timing issues related
to
: the CFFA not just the Apple ][.
:
: Please keep us posted on your progress.

One of the problems is that the CFFA's firmware
utilizes AUX RAM, which does not exist in the
Apple II or II+. Timing is also an issue, however,
I feel that timing would also be an issue in the
1 MHz IIe enhanced machine and it is not. I'm going
to try it in a IIe with 80 column card and no 64K
AUX RAM and see if the same problem exists there.
If it does, then I would assume that the AUX RAM
is the biggest of the 2 issues. Then, if the AUX
RAM is found to be the problem, I will go into the
firmware and see if I can get it to run in 64K and
if I'm successful, I will burn the eproms for people
that want to run them in their II and II+ Apples.

Bill @ GarberStreet Enterprizez };-)
Web Site - http://garberstreet.netfirms.com
Email - willy46pa @ comcast DOT net
Change DOT to a dot to contact me



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