🚀 go-pugleaf

In article <2b0a0a91.de77@grace.cri.nz> srgxnbs@grace.cri.nz writes:
>Its a long time since I played with DRAMS, but I would think that with 
>a bit of judicious programming you may be able to avoid a refresh 
>circuit. As long as you access all rows (columns?) within 4 ms the ram 
>gets refreshed, so while you're recording you'll be refreshing anyway, 
>ditto for playback. The rest of the time you could possibly arrange an 
>interrupt routine every 4 mS to just read the necessary number of 
>addresses if you can't build it into your program. If this is all B.S. 
>then someone please say so :)

No, it's a legitimate although tricky approach.  The very first Sun systems
used software refresh.  If you were really clever, you could hand-craft an
interrupt routine that did the refresh while also accomplishing something
useful (a friend of mine wrote a mouse-tracking refresh routine).

The trouble is, if that interrupt routine gets lost or has a bug, your
memory contents can evaporate.  Debugging such systems gets exciting.
Later-model Suns had hardware refresh.
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MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
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