[BBC-Micro] Reviving a dead BBC+
ken.lowe at btopenworld.com
Mon Apr 21 19:38:50 BST 2008
Mike Tomlinson wrote:
> NP. Good to hear you got it going; just out of interest, did you feel
> the RAM chips with the back of a finger to see if you could detect any
> temperature differences?
I did feel for heat around the RAM chips, but I never checked each chip
individually. Picking out the faulty chip was really just a lucky guess.
>>I intend to get hold of another 32K RAM chip and build a small circuit
>>that will hold both 32K RAM chips, and a single 32K ROM. This circuit
>>will then plug into one of the existing ROM sockets, with flying leads to
>>the three external points highlighted above, and a fourth to pick up page
>>0/1 select. This should provide me with a fully expanded 128K B+ with all
>>ROM sockets still available.
> Very nice :) I'd like to see photos of that if possible.
I'll post up some pics once I receive all the bits (waiting on 28 pin
sockets and RAM chips). Initially I'll build it on breadboard, so it might
look a bit messy. If it works as I expect, then I might make a proper PCB to
make it look a bit neater.
I've also ordered some bits to build an eprom programmer so I can create a
32K ROM with both ADFS (for my HDD), and DFS. I don't have the standard B+
DFS1770 V2.22 on EPROM and currently I'm having to copy it from my HDD into
the upper half of my new 32K RAM bank in order to see the ACORN OS 96K
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