DIY_EFI Digest Wednesday, 28 August 1996 Volume 01 : Number 250 In this issue: switching between EPROMS Re: switching between EPROMS Re: DIY_EFI Digest V1 #249 Re: switching between EPROMS Re: My DIY EFI Re: switching between EPROMS Re: switching between EPROMS See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: Warren Crowther Date: Wed, 28 Aug 1996 18:29:13 +1200 Subject: switching between EPROMS Hello All, quick question: has anyone made a device that you can plugs lots of EPROMs into, plug into your car ECU, and switch between them with a switch?? I want to make one for only 2 EPROMs, and was thinking of using a simple switch to switch the chip enable between the EPROMs. Will this work?? or will the time gap when neither of the EPROMs are enabled be enough to confuse the micro, and go into some unknown state? I could use latches and some simple logic chips to get around this I guess. Any recommendations?? thanks Warren _______________________________________________________________ Warren Crowther Software Engineer DDI +649 3610625 warren@xxx.nz Ph +649 3602834 x5625 Advantage Systems Ltd Fax +649 3764210 ------------------------------ From: arthurok@xxx.com (ARTHUR OKUN) Date: Tue, 27 Aug 1996 23:17:53 -0700 Subject: Re: switching between EPROMS only switch eproms with the ignition OFF then their should be no problems ------------------------------ From: talltom Date: Tue, 27 Aug 1996 23:21:04 -0700 (PDT) Subject: Re: DIY_EFI Digest V1 #249 >---------------------------------------------------------------------- > >From: Craig Pugsley >Date: Tue, 27 Aug 1996 19:57:40 +1000 (EST) >Subject: Re Propane injectors > >> Now if anybody knows about where I can get pulsed injectors that will >> work with liquid propane? > >A crowd over here (.au) uses stock ford (=bosch??) injectors, but fed >from the bottom of the injector via a slot in the body, after the coil. > >The rail pressure is regulated by restricing the return line, and the >un-used fuel flows "out" where gasoline USUALLY comes in. > >The whole system is at tank pressure (350psi??), and the injector >opening times are very short. > >Is there such a thing as an electronically controlled diesel injector? >(aka instead of the usual mechanical fuel pump distributor thing..) > >Cheers, >Craig. > >go efi555 See Detroit Diesel Engine Control, it's a neat program, easily programable, and just might not be hard to adapt to gas efi. ------------------------------ From: dzorde@xxx.au Date: Wed, 28 Aug 96 15:20:23 Subject: Re: switching between EPROMS If you switch it with the engine turned OFF, I don't think you'd have a problem. ______________________________ Reply Separator _________________________________ Subject: switching between EPROMS Author: diy_efi@xxx.edu at INTERNET Date: 8/28/96 3:04 PM Hello All, quick question: has anyone made a device that you can plugs lots of EPROMs into, plug into your car ECU, and switch between them with a switch?? I want to make one for only 2 EPROMs, and was thinking of using a simple switch to switch the chip enable between the EPROMs. Will this work?? or will the time gap when neither of the EPROMs are enabled be enough to confuse the micro, and go into some unknown state? I could use latches and some simple logic chips to get around this I guess. Any recommendations?? Warren _______________________________________________________________ Warren Crowther Software Engineer DDI +649 3610625 warren@xxx.nz Ph +649 3602834 x5625 Advantage Systems Ltd Fax +649 3764210 ------------------------------ From: pfontana@xxx.it (fontana pasquale) Date: Wed, 28 Aug 96 09:25:36 +0200 Subject: Re: My DIY EFI Could you give me more info about your system, and the cost of it? I want to buy three just now if the "system" is okay!!! I'm waiting for your e-mail. PASQUALE pfontana@xxx.it ------------------------------ From: pfontana@xxx.it (fontana pasquale) Date: Wed, 28 Aug 96 09:55:24 +0200 Subject: Re: switching between EPROMS Hello Warren To switch two eprom or two different bank (range address) of memory the problem is the same : you must disable your ECU then change and after rearm your SYSTEM. In other word , you must go off the ENGINE then switch. The problem for to make a change when the engine is running is very very complex. I think you dont need the opportunity to switch your ECU when is running . In this case is necessary a simple switch for to controll the CS (chip select) and the OE (output enable) for the two device: when first is ON the second must be OFF . The problem is very semplified if you use a device who is 2X of memory . EX for to switch two 27128 chip you must have a 27256 and controll the pin for the MSB A15 (if i remember) . If you want to use the first bank this pin must to be " 0 " (ground ) for the second " 1 " (+ VCC ) . BYE Pasquale >Hello All, > >quick question: > >has anyone made a device that you can plugs lots of EPROMs into, plug into >your car ECU, and switch between them with a switch?? > >I want to make one for only 2 EPROMs, and was thinking of using a simple >switch to switch the chip enable between the EPROMs. Will this work?? or >will the time gap when neither of the EPROMs are enabled be enough to >confuse the micro, and go into some unknown state? > >I could use latches and some simple logic chips to get around this I guess. > >Any recommendations?? > >Warren >_______________________________________________________________ >Warren Crowther >Software Engineer DDI +649 3610625 >warren@xxx.nz Ph +649 3602834 x5625 >Advantage Systems Ltd Fax +649 3764210 > > > > ------------------------------ From: Warren Crowther Date: Wed, 28 Aug 1996 21:06:11 +1200 Subject: Re: switching between EPROMS > If you switch it with the engine turned OFF, I don't think you'd have > a problem. This is a simple solution, and will work, but.. I'd prefer to do it with the engine ON!!! I don't see any reason why it cannot be done, provided the switch over is not done at a critical time, and that the only difference between the EPROMS is the data: ie. the fuelling, ignition timing, etc. Also it should be done quick enough so that the micro does not miss an external data fetch (anyone know what the micro will do in this case?? will it hang or retry? ). Warren >______________________________ Reply Separator _________________________________ >Subject: switching between EPROMS >Author: diy_efi@xxx.edu at INTERNET >Date: 8/28/96 3:04 PM > > >Hello All, > >quick question: > >has anyone made a device that you can plugs lots of EPROMs into, plug into >your car ECU, and switch between them with a switch?? > >I want to make one for only 2 EPROMs, and was thinking of using a simple >switch to switch the chip enable between the EPROMs. Will this work?? or >will the time gap when neither of the EPROMs are enabled be enough to >confuse the micro, and go into some unknown state? > >I could use latches and some simple logic chips to get around this I guess. > >Any recommendations?? > >Warren >_______________________________________________________________ >Warren Crowther >Software Engineer DDI +649 3610625 >warren@xxx.nz Ph +649 3602834 x5625 >Advantage Systems Ltd Fax +649 3764210 > > > > _______________________________________________________________ Warren Crowther (from home) Software Engineer DDI +649 3610625 warren@xxx.nz Ph +649 3602834 x5625 Advantage Systems Ltd Fax +649 3764210 ------------------------------ End of DIY_EFI Digest V1 #250 ***************************** To subscribe to DIY_EFI-Digest, send the command: subscribe diy_efi-digest in the body of a message to "Majordomo@xxx. 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