1.1 --- a/Electron.txt Sun Apr 12 17:05:08 2020 +0200
1.2 +++ b/Electron.txt Mon Apr 13 17:05:49 2020 +0200
1.3 @@ -100,6 +100,18 @@
1.4 component cost increase proving to be less than projections made early in the
1.5 design process, particularly if slower (and smaller) RAM chips became usable.
1.6
1.7 +In the document "One of the Most Popular 65,536-Bit (64K) Dynamic RAMs The TMS
1.8 +4164", a note is made of 4164 RAM prices dropping from $25 to $5 per unit in
1.9 +1981. Perhaps the initial pricing influenced the design process, anticipating
1.10 +costs of $100 for 32K of RAM and the need for a reduced number of memory
1.11 +chips. Had the subsequent pricing been noted or anticipated, a decision might
1.12 +have been made to employ eight 64Kbit chips, which would have afforded
1.13 +additional capabilities due to the doubling of RAM (such as shadow memory) for
1.14 +less than half of the originally anticipated memory costs. (Naturally, eight
1.15 +32Kbit memory chips, which might also have exhibited similar price reductions,
1.16 +would potentially have offered the delivered 32K for an even smaller fraction
1.17 +of the anticipated costs.)
1.18 +
1.19 Improving Display Capabilities
1.20 ------------------------------
1.21
2.1 --- a/ULA.txt Sun Apr 12 17:05:08 2020 +0200
2.2 +++ b/ULA.txt Mon Apr 13 17:05:49 2020 +0200
2.3 @@ -136,6 +136,8 @@
2.4 http://chrisacorns.computinghistory.org.uk/docs/Acorn/Manuals/Acorn_ElectronSM.pdf
2.5 See: http://mdfs.net/Docs/Comp/Electron/Techinfo.htm
2.6 See: http://stardot.org.uk/forums/viewtopic.php?p=120438#p120438
2.7 +See: One of the Most Popular 65,536-Bit (64K) Dynamic RAMs The TMS 4164
2.8 + http://smithsonianchips.si.edu/augarten/p64.htm
2.9
2.10 A Note on 8-Bit Wide RAM Access
2.11 -------------------------------