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71B MultiMod: MEMORY LOST when changing batteries?
04-21-2021, 11:38 PM
Post: #18
RE: 71B MultiMod: MEMORY LOST when changing batteries?
(04-21-2021 09:14 PM)rprosperi Wrote:  
(04-21-2021 06:28 PM)Dave Frederickson Wrote:  Both the CMT and HHP 32k modules have a signal pin that corresponds to the Last-Chip-In-Module bit in the FRAM71 configuration nibble. It's possible to open the modules and reconfigure how the LCIM pins are connected to create RAM ports greater that 32k. There is a bug with the 1BBBB firmware and 64k ports, so be aware.

FRAM71? Did you just mean 71B config table? Maybe I'm not following you about FRAM71?

I was referring to vanilla CMT & HHP modules as sold, but yes, this can be done, if you're intrepid and have a steady hand. One of my HHP 96K modules has been so converted to 64K/32K RAM module, which is handy for mastering 64K EPROM images, though Emu71/DOS and Emu71/Win are likely just as easy to use.

The FRAM71 LCIM bit in the config nibble corresponds to the pin on the memory module used to configure the 3 modules in the HHP module. We discussed this at length before I attempted to replace the RAM chips on your 96k module.

Dave
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RE: 71B MultiMod: MEMORY LOST when changing batteries? - Dave Frederickson - 04-21-2021 11:38 PM



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