0001012870-99-004152 SC 13D/A 2 19991112 DIAMETRICS MEDICAL INC 0000895380 3845 411663185 MN 1231 SC 13D/A 34 005-42757 99749963 2658 PATTON RD ROSEVILLE MN 55113 6516398035 2658 PATTON ROAD ROSEVILLE MN 55113 HEWLETT PACKARD CO 0000047217 3570 941081436 DE 1031 SC 13D/A 3000 HANOVER ST PALO ALTO CA 94304 4158571501 3000 HANOVER ST MS 20BL PALO ALTO CA 94304 SC 13D/A 1 000101287099004152-001-seq1-sc-13d-a.txt FORM SC 13D/A EX-99.(A) 2 000101287099004152-002-seq2-ex-99-a.txt LETTER AGREEMENT DATED OCTOBER 21, 1999