{"id":1228,"date":"2015-11-06T22:45:38","date_gmt":"2015-11-06T22:45:38","guid":{"rendered":"http:\/\/www.sydneysmith.com\/wordpress\/?p=1228"},"modified":"2017-05-14T01:40:52","modified_gmt":"2017-05-14T01:40:52","slug":"hp67-internals-s-9-and-12","status":"publish","type":"post","link":"https:\/\/www.sydneysmith.com\/wordpress\/1228\/hp67-internals-s-9-and-12\/","title":{"rendered":"HP67 Internals – S 9 and 12"},"content":{"rendered":"

The HP67 internal flags S 9 and S 12 are used during keyboard data entry. The meanings for S9,S12 are:<\/p>\n

0,0 – Overwrite X register.
\ne.g. CLx or ENTER was just pressed.<\/p>\n

1,0 – Lift stack.
\nDigit (or “.” or EEX) causes Z to T, Y to Z and X to Y; then what you key in overwrites X. This is what happens after you have calculated something.
\ne.g. 4 ENTER 5 + (“9.00″ displayed) 6 (Y=9.00 X=”6.”).<\/p>\n

1,1 – Input digit.
\nAfter you press the first digit (or “.” or EEX ?) S 12 gets set to 1. From then on, digits get added to the RHS as you key them in.<\/p>\n\n\n\n\n\n\n\n\n
CLx<\/td>\n“0.00” displayed, S 9 = 0, S 12 = 0<\/td>\n<\/tr>\n
1<\/td>\n“1.” displayed, S 9 = 1, S 12 = 1<\/td>\n<\/tr>\n
2<\/td>\n“12.” displayed, S 9 = 1, S 12 = 1<\/td>\n<\/tr>\n
3<\/td>\n“123.” displayed, S 9 = 1, S 12 = 1<\/td>\n<\/tr>\n
ENTER<\/td>\nY=123.00, X=123.00, “123.00” displayed, S 9 = 0, S 12 = 0<\/td>\n<\/tr>\n
4<\/td>\n“4.” displayed, S 9 = 1, S 12 = 1<\/td>\n<\/tr>\n
+<\/td>\n“127.00” displayed, S 9 = 1, S 12 = 0<\/td>\n<\/tr>\n<\/table>\n

You can see this working in the hp67u emulator. Simply press a button then menu Advanced and look at the “S=…” item. you’ll see “.9..c.” if S 9 and S 12 are 1,
\nyou’ll see “.9….” if just S 9 is 1, or
\nyou’ll see “……” if both are 0.<\/p>\n","protected":false},"excerpt":{"rendered":"

The HP67 internal flags S 9 and S 12 are used during keyboard data entry. The meanings for S9,S12 are:<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[16,5,3],"tags":[33],"_links":{"self":[{"href":"https:\/\/www.sydneysmith.com\/wordpress\/wp-json\/wp\/v2\/posts\/1228"}],"collection":[{"href":"https:\/\/www.sydneysmith.com\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.sydneysmith.com\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.sydneysmith.com\/wordpress\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.sydneysmith.com\/wordpress\/wp-json\/wp\/v2\/comments?post=1228"}],"version-history":[{"count":3,"href":"https:\/\/www.sydneysmith.com\/wordpress\/wp-json\/wp\/v2\/posts\/1228\/revisions"}],"predecessor-version":[{"id":1231,"href":"https:\/\/www.sydneysmith.com\/wordpress\/wp-json\/wp\/v2\/posts\/1228\/revisions\/1231"}],"wp:attachment":[{"href":"https:\/\/www.sydneysmith.com\/wordpress\/wp-json\/wp\/v2\/media?parent=1228"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.sydneysmith.com\/wordpress\/wp-json\/wp\/v2\/categories?post=1228"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.sydneysmith.com\/wordpress\/wp-json\/wp\/v2\/tags?post=1228"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}