# HG changeset patch # User Paul Boddie # Date 1586790349 -7200 # Node ID 8b00fd59f03ac642cea6dc4cd55765ceb1dddc13 # Parent b3383787c26f3ad6baf7baf47ea5ae19a0fb9ccf Added notes on 4164 RAM costs referencing historical remarks. diff -r b3383787c26f -r 8b00fd59f03a Electron.txt --- a/Electron.txt Sun Apr 12 17:05:08 2020 +0200 +++ b/Electron.txt Mon Apr 13 17:05:49 2020 +0200 @@ -100,6 +100,18 @@ component cost increase proving to be less than projections made early in the design process, particularly if slower (and smaller) RAM chips became usable. +In the document "One of the Most Popular 65,536-Bit (64K) Dynamic RAMs The TMS +4164", a note is made of 4164 RAM prices dropping from $25 to $5 per unit in +1981. Perhaps the initial pricing influenced the design process, anticipating +costs of $100 for 32K of RAM and the need for a reduced number of memory +chips. Had the subsequent pricing been noted or anticipated, a decision might +have been made to employ eight 64Kbit chips, which would have afforded +additional capabilities due to the doubling of RAM (such as shadow memory) for +less than half of the originally anticipated memory costs. (Naturally, eight +32Kbit memory chips, which might also have exhibited similar price reductions, +would potentially have offered the delivered 32K for an even smaller fraction +of the anticipated costs.) + Improving Display Capabilities ------------------------------ diff -r b3383787c26f -r 8b00fd59f03a ULA.txt --- a/ULA.txt Sun Apr 12 17:05:08 2020 +0200 +++ b/ULA.txt Mon Apr 13 17:05:49 2020 +0200 @@ -136,6 +136,8 @@ http://chrisacorns.computinghistory.org.uk/docs/Acorn/Manuals/Acorn_ElectronSM.pdf See: http://mdfs.net/Docs/Comp/Electron/Techinfo.htm See: http://stardot.org.uk/forums/viewtopic.php?p=120438#p120438 +See: One of the Most Popular 65,536-Bit (64K) Dynamic RAMs The TMS 4164 + http://smithsonianchips.si.edu/augarten/p64.htm A Note on 8-Bit Wide RAM Access -------------------------------