On Wed, 30 Aug 1995, Conny Andersson wrote: > Wayne G Boyd wrote about not beeing able to program an OTP 16c55 ... > > I guess it's as simple as this: > > You said you programmed the JW in HS-mode and then tried to program > the 16c55-xt/p also in HS-mode, right? > > The OTP 16c55-xt/p is preprogrammed in xt-mode (up to 4MHz) so this > might be the problem. I don't know what happens when you program > HS-mode in an XT-mode OTP but my guess is that nothing happens at all. > > Have you tried to run the chip at 8MHz, 4MHz? It should definitely work > at 4MHz. > > ------------------------------- > Conny Andersson, LiTH The newer ``enhanced'' 16C5XA parts are fuse-programmable for oscillator type, whether OTP or windowed; the ``dash'' suffix in the part number indicates a speed grade, e.g. PIC16C54A-04/P, PIC16C57A-20I/SO, etc., where the `I' is a temperature-grade option. The older ``traditional'' ;-) 16C5X parts are fuse-programmable in the windowed package (/JW), but the OTP versions are factory preset (probably with the same fuses, so you might be able to monkey around a bit if you try to burn additional ones); the ``dash'' suffix in the part number indicates an oscillator type, e.g. PIC16C54A-RC/P, PIC16C57A-HSI/SO, etc., where the `I' is a temperature-grade option. Peter F. Klammer, Racom Systems Inc. PKlammer@ACM.Org 6080 Greenwood Plaza Boulevard (303)773-7411 Englewood, CO 80111 FAX:(303)771-4708