ahenden@magnus.acs.ohio-state.edu (Arne A Henden) (05/07/91)
Wouldn't you know it, just when all the threads regarding replacing an 8250 with a 16550 get deleted from our server, we get involved in an equivalent project? We are replacing the 16450's on our 4-port serial card with 16550's because of PC/NFS's habit of turning off interrupts for extended periods of time. Anyway, the 16550 works just fine in 16450 mode, but as soon as we put it in 550 mode it no longer creates interrupts. Would someone who has worked with the 550, or who has saved the prior posts regarding this chip, give us a reply? Thanks. Arne Henden
steve@nuchat.sccsi.com (Steve Nuchia) (05/09/91)
In article <1991May6.171901.21249@magnus.acs.ohio-state.edu> ahenden@magnus.acs.ohio-state.edu (Arne A Henden) writes: >for extended periods of time. Anyway, the 16550 works just >fine in 16450 mode, but as soon as we put it in 550 mode it >no longer creates interrupts. This is true. The 16550 ----> Does Not Work <---- Specify 16550A. The current production plastic dip parts (last time I bought a batch, anyway) are labelled NS16550AFN. The A is critical, without it you have junk. Western Digital second-sources the non-A part, but that doesn't help since they don't work. -- Steve Nuchia South Coast Computing Services (713) 964-2462 "Innocence is a splendid thing, only it has the misfortune not to keep very well and to be easily misled." --- Immanuel Kant, Groundwork of the Metaphysic of Morals
jimc@isc-br.ISC-BR.COM (Jim Cathey) (05/10/91)
In article <1991May9.003258.17410@nuchat.sccsi.com> steve@nuchat.sccsi.com (Steve Nuchia) writes: >This is true. The 16550 ----> Does Not Work <---- > >Specify 16550A. The current production plastic dip parts (last time I >bought a batch, anyway) are labelled NS16550AFN. The A is critical, >without it you have junk. Amazing. I had no idea they'd emulated the 8250 so completely. I can't remember which, but one of the 8250, A, or B parts didn't work either. Love them PC's. +----------------+ ! II CCCCCC ! Jim Cathey ! II SSSSCC ! ISC-Bunker Ramo ! II CC ! TAF-C8; Spokane, WA 99220 ! IISSSS CC ! UUCP: uunet!isc-br!jimc (jimc@isc-br.isc-br.com) ! II CCCCCC ! (509) 927-5757 +----------------+ "With excitement like this, who is needing enemas?"