The MCM68766 can always be replaced by a 2764 using a 28 dip socket to 24 dip header.? I don't have a 7854 and didn't look up the specs, but need to check the access time.? I built a few adapters for the Commodore 64 computer and 1541 disk drive.? The rom in the 1541 was close to the TO3 voltage regulator and the heat seemed to cause failures.? Replacements worked great.? If details are needed and you can't find it on the internet, I can look through my junk for the method I used.? I also copied Commodore? roms to MCM68766.??
Carl Hallberg (W9CJH)
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On Tuesday, April 5, 2022, 05:58:21 PM CDT, Raymond Domp Frank <hewpatek@...> wrote:
On Tue, Apr? 5, 2022 at 06:31 AM, Ram wrote:
For 7854 owners who have been suffering from the ROM Rot problem with their
EPROMS
A few years ago, our member Holger L¨¹bben designed a replacement ROM card using commonly available components.
He had complete sets and kits available. See this thread:
/g/TekScopes/topic/76166880#170558The board contains the complete operating software and also supports the diagnostic mode, to be selected by an on-board switch..
I'm lucky enough to have one and it works very well.
AFAIK, it's out of stock and he does not intend to produce more.
Raymond
