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From: robertwessel2 on 23 Jun 2010 19:28 On Jun 23, 4:50 pm, Jon Kirwan <j...(a)infinitefactors.org> wrote: > On Wed, 23 Jun 2010 21:04:55 +0000 (UTC), Grant Edwards > > > > > > <inva...(a)invalid.invalid> wrote: > >On 2010-06-23, Jon Kirwan <j...(a)infinitefactors.org> wrote: > >> On Wed, 23 Jun 2010 14:13:14 +0200, "Meindert Sprang" > >><m...(a)NOJUNKcustomORSPAMware.nl> wrote: > > >>>"Paul Keinanen" <keina...(a)sci.fi> wrote in message > >>>news:9pe3269vevlnos3fn3j1ne6dv7tnfgm293(a)4ax.com... > >>>> At 62.5 kbit/s the bit time is 16 us, thus +/-8 us error from the > >>>> nominal sampling point from the middle of the bit period would be > >>>> allowed. > > >>>Funny, all the discussions about baudrates and errors. I'd use an ISA COM > >>>card and simply replace the crystal... done it, works like a charm. Only 5 > >>>minutes work. > > >> Hehe. But this means you actually _have_ something with an > >> ISA bus on it!! These days... well. > > >Then use a PCI card. > > >> On your point, yes. A crystal change on any of the usual > >> spate of old ISA boards would easily solve the problem. > >> Forgotten lore. > > >It works for PCI cards as well. > > I like ISA and simpler software. > > Although I understand reflection wave principles, clock line > skew and serpentine clock lines, and the like, I very much > appreciate being able to use simple logic, wire-wrapping > techniques, and custom circuit design with the ISA bus. It > is a low-tech bus that can be reached by hobbyists. PCI, and > not merely because of the hardware but also because of other > aspects (plug and play), out of reach of most hobbyist tools > and skills. > > And I also understand the desire to get rid of the south > bridge, chipset side-band channels to support ISA DMA over a > bus that simply cannot and does not support ISA DMA timing > requirements, interrupt mapping, and so on. It's pretty > obvious this was a huge source of continuing chipset bugs and > needed testing regimes, as well. > > But I like ISA. Just slap something like a PLX 9052 on your PCI board. The front side handles the PCI, the back side is ISA.
From: Jon Kirwan on 23 Jun 2010 19:43 On Wed, 23 Jun 2010 16:28:56 -0700 (PDT), "robertwessel2(a)yahoo.com" <robertwessel2(a)yahoo.com> wrote: >On Jun 23, 4:50�pm, Jon Kirwan <j...(a)infinitefactors.org> wrote: >> On Wed, 23 Jun 2010 21:04:55 +0000 (UTC), Grant Edwards >> >> <inva...(a)invalid.invalid> wrote: >> >On 2010-06-23, Jon Kirwan <j...(a)infinitefactors.org> wrote: >> >> On Wed, 23 Jun 2010 14:13:14 +0200, "Meindert Sprang" >> >><m...(a)NOJUNKcustomORSPAMware.nl> wrote: >> >> >>>"Paul Keinanen" <keina...(a)sci.fi> wrote in message >> >>>news:9pe3269vevlnos3fn3j1ne6dv7tnfgm293(a)4ax.com... >> >>>> At 62.5 kbit/s the bit time is 16 us, thus +/-8 us error from the >> >>>> nominal sampling point from the middle of the bit period would be >> >>>> allowed. >> >> >>>Funny, all the discussions about baudrates and errors. I'd use an ISA COM >> >>>card and simply replace the crystal... done it, works like a charm. Only 5 >> >>>minutes work. >> >> >> Hehe. �But this means you actually _have_ something with an >> >> ISA bus on it!! �These days... well. >> >> >Then use a PCI card. >> >> >> On your point, yes. �A crystal change on any of the usual >> >> spate of old ISA boards would easily solve the problem. >> >> Forgotten lore. >> >> >It works for PCI cards as well. >> >> I like ISA and simpler software. >> >> Although I understand reflection wave principles, clock line >> skew and serpentine clock lines, and the like, I very much >> appreciate being able to use simple logic, wire-wrapping >> techniques, and custom circuit design with the ISA bus. �It >> is a low-tech bus that can be reached by hobbyists. �PCI, and >> not merely because of the hardware but also because of other >> aspects (plug and play), out of reach of most hobbyist tools >> and skills. >> >> And I also understand the desire to get rid of the south >> bridge, chipset side-band channels to support ISA DMA over a >> bus that simply cannot and does not support ISA DMA timing >> requirements, interrupt mapping, and so on. �It's pretty >> obvious this was a huge source of continuing chipset bugs and >> needed testing regimes, as well. >> >> But I like ISA. > >Just slap something like a PLX 9052 on your PCI board. The front side >handles the PCI, the back side is ISA. I still can't just wire-wrap the PCI bus side of it. 1.5" +/- 0.1" clock line, serpentined, 2ns clock skew at 33MHz and 1ns at 66, etc. I suppose pre-built boards with chips down and the ISA back-side might do it. But this, again, is getting way over my hobbyist toolset. If there is a problem with the PCI bus, I simply don't have the tools to diagnose. They are kind of expensive, too. Also, no plug-and-play, required PCI transaction support and registers to deal with, etc. ISA is __very__ easy. Add PCI, even if only on a corner of it, and complexity goes ^^^ up. I'm glad to keep the older machines around for hobby playing. They work VERY well, even to this day. And Win98SE licensing fits my model and boots _very_ quickly, well. Jon
From: David Brown on 24 Jun 2010 02:57 On 23/06/2010 23:50, Jon Kirwan wrote: > On Wed, 23 Jun 2010 21:04:55 +0000 (UTC), Grant Edwards > <invalid(a)invalid.invalid> wrote: > >> On 2010-06-23, Jon Kirwan<jonk(a)infinitefactors.org> wrote: >>> On Wed, 23 Jun 2010 14:13:14 +0200, "Meindert Sprang" >>> <ms(a)NOJUNKcustomORSPAMware.nl> wrote: >>> >>>> "Paul Keinanen"<keinanen(a)sci.fi> wrote in message >>>> news:9pe3269vevlnos3fn3j1ne6dv7tnfgm293(a)4ax.com... >>>>> At 62.5 kbit/s the bit time is 16 us, thus +/-8 us error from the >>>>> nominal sampling point from the middle of the bit period would be >>>>> allowed. >>>> >>>> Funny, all the discussions about baudrates and errors. I'd use an ISA COM >>>> card and simply replace the crystal... done it, works like a charm. Only 5 >>>> minutes work. >>> >>> Hehe. But this means you actually _have_ something with an >>> ISA bus on it!! These days... well. >> >> Then use a PCI card. >> >>> On your point, yes. A crystal change on any of the usual >>> spate of old ISA boards would easily solve the problem. >>> Forgotten lore. >> >> It works for PCI cards as well. > > I like ISA and simpler software. > > Although I understand reflection wave principles, clock line > skew and serpentine clock lines, and the like, I very much > appreciate being able to use simple logic, wire-wrapping > techniques, and custom circuit design with the ISA bus. It > is a low-tech bus that can be reached by hobbyists. PCI, and > not merely because of the hardware but also because of other > aspects (plug and play), out of reach of most hobbyist tools > and skills. > ISA has also always been out of the reach of the hobbyist. While there is no doubt that it is simpler to design an ISA card than a PCI card, in the days of ISA it was hard to make such a card. Information about the bus wasn't as easily available (no Google), and even if you knew how to do it, the design of a card was not insignificant. But the biggest hurdle for a hobbyist would be testing - you need an expendable spare computer to test your card, because of the high risk of frying the whole machine. These days you can get a cheap PCI bus computer for very little, and second-hand ones for practically nothing. When ISA was the main bus, a spare computer was a big investment.
From: Meindert Sprang on 24 Jun 2010 03:10 "Jon Kirwan" <jonk(a)infinitefactors.org> wrote in message news:8715265o00dgu3msi6bra5d51n3sj2npvs(a)4ax.com... > Not so. I'm looking right now at two such cards, one ISA and > one PCI. The ISA board has a large, socketed crystal module. > The PCI a tiny, SMT unit. The skills required for modifying > one is much different Once you've done it a couple of times, you wonder why you ever made such a fuss about it :-) Bu then again, I am an embedded software and hardware guy.... Meindert
From: Meindert Sprang on 24 Jun 2010 03:16
"David Brown" <david(a)westcontrol.removethisbit.com> wrote in message news:4c23020b$0$4113$8404b019(a)news.wineasy.se... > ISA has also always been out of the reach of the hobbyist. While there > is no doubt that it is simpler to design an ISA card than a PCI card, in > the days of ISA it was hard to make such a card. Information about the > bus wasn't as easily available (no Google), and even if you knew how to > do it, the design of a card was not insignificant. I designed a few cards back in the 90's. Information was not hard to come by, Intel provided the spec, IIRC, and as long as you double-triple-quadruple checked the power connections, the only serious thing that could happen is that your computer locked up when the card was inserted. And even that actually never happened to me. The hardest thing for me was to find a decent mechanical specification to make it fit into every computer case.. Meindert |