ramsey@NCoast.ORG (Cedric Ramsey) (12/10/90)
Hello again techies. I want to build an eprom programmer for the 8751 that will interface into an xt compatible computer system. I will generate the program on the pc and download it via eprom to the processor. I don't want to purchase such an device but can anybody give me information as to where I can find the plans to build such a device? It will probably be a lot cheaper an within my budget this way. Besides, I haven't seen any programmers for the 8751 anyway, omitting intel of course. I thougth about Circuit Cellar series but i'm not sure which issue; I don't have access to it anyway but it could be arranged if I knew which issue. Please send e-mail to: ramsey@ncoast.ORG Thankyou, Cedric A. Ramsey
steveh@tasman.cc.utas.edu.au (Steven Howell) (12/18/90)
i If you are still having problems locating a programmer, and are able to organise some sort of transport of the chip, I will be happy to down load the program you want for you. If you are interested, post me and we'll work something out. The Intel 87xx series are an excellent set of MPU's, which I use all the time for problem solving and system patches. Steve h .. ... Uni Of Tas
gordonl@microsoft.UUCP (Gordon LETWIN) (01/01/91)
Re: programmers for 8751s - there are three routes that you can go here. You can get a "universal" programmer that programs them directly - JDR sells one for about $500, I have one and it works. If you have a regular eprom programmer you can buy a little adaptor, for about $120, which will allow you to program an 8751/8752 as if it were a 2732-series eprom. This adaptor reduces the programming voltage, provides the crystal signal needed by the 8751, etc. I have one of these and it works. See the ads in the CirCuit Cellar magazine (forget title) or in the back of "embedded systems" mag. Finally, Dallas semi makes a 8751 equivalent that has 8 or 32K of battery backed RAM - good for at least 10 years. You can dynamically assign the ram to be either "eprom" or "extended RAM" so that you can have, say, 16K of code and 16K of extra RAM. These chips are programmed over the built in serial port (they have a built in ROM monitor!) - you just give them the "accept program" command and then feed them Intel format, as I recall. They range from $80 to $120 in oneies, but they have three big benefits: 1) you can buy them in onesies directly from Dallas Semi, and 2) they require no programming support besides a serial port on your PC 3) you can debug your program by writting log info into the extra ram and then, after the crash, read that log info back out via the built in ROM monitor. Not nearly as good as an ICE, of course, but sometimes a very useful technique. So if you're using a small # of chips, the dallas route makes sense; their higher cost eliminates the need for a programmer and may eliminate the need for an ICE. gordon letwin