Tag Archives: solution

Electronics and Computers, Mac OS 8, Mac OS 9, Macintosh, Posts, System 7

Virtual Memory Not Working on Classic Mac OS

Virtual Memory Not Working on Classic Mac OS

When you have a lot of physical RAM installed in your Mac OS Classic era Macintosh, sometimes you might find that it isn’t possible to enable Virtual Memory. This can be a problem as some software, especially games, refuses to launch if you don’t have Virtual Memory enabled.

In this situation, one trick can be to create a large RAM disk using the Memory control panel. This consumes a load of the available System memory and magically makes the Virtual Memory options re-appear.

Once you’ve finished with the software that requires Virtual Memory, delete the contents of the RAM disk (if there is any) – fastest way is to just to select the icon on the desktop and then Erase from the Special menu, then turn off RAM Disk in the Memory control Panel.

Electronics and Computers, Linux, Posts, Programming

Programming a AT28C64 with a TL866ii Plus

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Quick note to help other people in a similar situation…

I was trying to burn the ROM form my breadboard Z80 project based on Grant Searle’s design, but was having verification errors when using either Xgpro running in Wine (on Linux) or minipro from the command line. I was trying to burn the ROM to a 64 Mbit AT28C64 (Atmel) chip.

TL718

In frustration, I tried selecting an equivalent AMD part, the AMD28C64A, and it worked first time. This is after hours spent trying to get the other settings working, worrying I hadn’t done something right, trying to change the programming speed and worrying that my chips were dead.

Hope this note helps someone else. Not the best first experience with the device. Even more annoying that it works just fine with the AT28C64B.

Here are some of the various errors I was getting :

Verification failed at address 0x0001: File=0xC3, Device=0xFF

ERROR! CODE Address0x000001 Buf_Val:0xC3 IC_Val:0xFF