lmb@mhuxm.UUCP (breda) (04/17/84)
I have an intermittent problem with a Tecmar Labmaster A/D board in a Compaq PC compatible. The hardware test software is written in assembly language and is called by a C program. It simply reads the A/D, fills a 1000 element stack and then returns. Everything works fine when the Compaq is first turned on. (The test signal is a sinusoid.) However, after a few runs, the high byte is read as a low number, when it should be 0xF. This only happens with low negative numbers. The outputs from the A/D are okay, but they are not getting to memory. Particulars: - 512K bytes on-board memory - CI-86 C - also have Tecmar Winchester 33/share expansion unit Any suggestions? Anyone else run into this? Thanks. Loreen Breda AT&T Bell Laboratories (201)-582-7009 mhuxm!lmb