Post by thread:[EE]: eprom programmer needed for 2708 eproms

Good day to all. Our local science centre / planetarium has had some problems with their Zeiss Star Projector. It looks as if they have solved these problems, but during the course of the testing, it looked as if some of the eproms were starting to lose bits. I suggested that one of their priorities was to read and save images of the eprom contents. The problem is that it looks as if the eproms are 2708 and I have nothing that will read them. Does anyone have an old programmer that they could loan for a couple of weeks? A Canadian source would be the easiest, USA would be OK as well. Wait a minute - I just dug up an old GTEK programmer that *might* date from that era but have neither software or documentation for it. I'm heading off to google to see what I can find out about it. In the meantime, any suggestions gratefully accepted. dwayne PS - the following is the info I have from techs at the site. Does 'U55C' look like a good cross to 2708? At 03:10 PM 2/2/01 -0700, spam_OUTesscTakeThisOuTplanet.eon.net wrote: {Quote hidden}> EPROM used in Zeiss Star Projector are U555C. Closest cross > we could >find was for U555D (looks interchangeable from our schematics), which is >equivalent to ECG 2708. Voltages for this 24-p DIP are +5, -5, and +12. > > --D > Bodnar 452-9100 Dwayne Reid <.....dwaynerKILLspam@spam@planet.eon.net> Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax Celebrating 17 years of Engineering Innovation (1984 - 2001) * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Do NOT send unsolicited commercial email to this email address. This message neither grants consent to receive unsolicited commercial email nor is intended to solicit commercial email. -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

I have five 2708's I will donate to the cause if so desired. I worked during graduate school at the Morehead Planetarium in Chapel Hill, NC where they have a Zeiss Model VI projector - thus a soft spot for their predicament. David V. Fansler Network Administrator TriPath Imaging, Inc. (formerly AutoCyte, Inc.) 1-800-426-2176 ext 261 Now Showing http://www.dv-fansler.com Ann Fansler (December 1, 1956 - September 23, 2000) {Original Message removed}

On Fri, 2 Feb 2001 18:05:32 -0700, you wrote: Easiest way to read them may be to make up a little adapter board to supply the wacky supply voltages, and read them on a conventional programmer. You should be able to bodge a modern eprom into the old sockets without too much hacking - just keep those silly voltages away from it! {Quote hidden}>Good day to all. > >Our local science centre / planetarium has had some problems with their >Zeiss Star Projector. It looks as if they have solved these problems, but >during the course of the testing, it looked as if some of the eproms were >starting to lose bits. I suggested that one of their priorities was to >read and save images of the eprom contents. > >The problem is that it looks as if the eproms are 2708 and I have nothing >that will read them. Does anyone have an old programmer that they could >loan for a couple of weeks? A Canadian source would be the easiest, USA >would be OK as well. > >Wait a minute - I just dug up an old GTEK programmer that *might* date from >that era but have neither software or documentation for it. I'm heading >off to google to see what I can find out about it. In the meantime, any >suggestions gratefully accepted. > >dwayne > >PS - the following is the info I have from techs at the site. Does 'U55C' >look like a good cross to 2708? > >At 03:10 PM 2/2/01 -0700, esscKILLspamplanet.eon.net wrote: >> EPROM used in Zeiss Star Projector are U555C. Closest cross >> we could >>find was for U555D (looks interchangeable from our schematics), which is >>equivalent to ECG 2708. Voltages for this 24-p DIP are +5, -5, and +12. >> >> --D >> Bodnar 452-9100 > > > > >Dwayne Reid <.....dwaynerKILLspam.....planet.eon.net> >Trinity Electronics Systems Ltd Edmonton, AB, CANADA >(780) 489-3199 voice (780) 487-6397 fax > >Celebrating 17 years of Engineering Innovation (1984 - 2001) > >* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * >Do NOT send unsolicited commercial email to this email address. >This message neither grants consent to receive unsolicited >commercial email nor is intended to solicit commercial email. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

You can make a temporary adapter to a 2716-pinout socket (2 stacked sockets) and use the programmer you have to read them out. You will need a small auxiliary PSU for -5V and +12V. Always connect -5V first and disconnect last. The read out image will repeat itself twice in the object file. You will need to fix that later. hope this helps, Peter -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

At 02:36 PM 2/3/01 +0000, you wrote: >On Fri, 2 Feb 2001 18:05:32 -0700, you wrote: > >Easiest way to read them may be to make up a little adapter board to >supply the wacky supply voltages, and read them on a conventional >programmer. You should be able to bodge a modern eprom into the old >sockets without too much hacking - just keep those silly voltages away >from it! The supplies need sequencing, be sure to get ahold of a data sheet. It might be just as easy if you are going to that trouble to hack up a programmer entirely from scratch. IIRC, the 2708 just takes 50ms pulses for each byte. Dead easy. A parallel port on an old PC will have all the logic required (use an HC4040 to generate the addresses), and also the supply voltages (but check sequencing, it's probably ok in that case). The programming voltage Vpp is something relatively high, but a bench supply could take care of that, with a suitable electronic switch. Best regards, =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Spehro Pefhany --"it's the network..." "The Journey is the reward" EraseMEspeffspam_OUTTakeThisOuTinterlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com Contributions invited->The AVR-gcc FAQ is at: http://www.bluecollarlinux.com =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

Dwayne Reid wrote: {Quote hidden}> > Good day to all. > > Our local science centre / planetarium has had some problems with their > Zeiss Star Projector. It looks as if they have solved these problems, but > during the course of the testing, it looked as if some of the eproms were > starting to lose bits. I suggested that one of their priorities was to > read and save images of the eprom contents. > > The problem is that it looks as if the eproms are 2708 and I have nothing > that will read them. Does anyone have an old programmer that they could > loan for a couple of weeks? A Canadian source would be the easiest, USA > would be OK as well. > > Wait a minute - I just dug up an old GTEK programmer that *might* date from > that era but have neither software or documentation for it. I'm heading > off to google to see what I can find out about it. In the meantime, any > suggestions gratefully accepted. > > dwayne Maybe 'The Engine' could be used to read obsolete devices like this. http://www.picnpoke.com/engine.html -- Best regards Tony mICro's http://www.picnpoke.com salesspam_OUTpicnpoke.com -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email @spam@listservKILLspammitvma.mit.edu with SET PICList DIGEST in the body

A 2708 does not program with single program pulses like a 2716 and later devices use. It requires a repeating loop to program each address sequentially for 1mS right through the whole device and then loop through the whole device at least 50 times. This is necessary as the internal structure of the device gives a lot of cross talk between cells during programming. If you program it with a single 50mS pulse to one address and then move on you will find the contents of previously programmed cells will change as you program later cells. If you get really stuck I may be able to find an early Intel data book I could scan. I do not think I threw it out when I moved half way round the world. -- http://www.piclist.com hint: To leave the PICList KILLspampiclist-unsubscribe-requestKILLspammitvma.mit.edu

Many thanks for the suggestions, Follks. Many of you responded with exactly the same idea and I think that it is exactly what I'll do. At 07:07 PM 2/2/01 -0700, Robert Rolf wrote: >Hi Dwayne, > >Some weeks ago I told David to call me back if my suggestions didn't >work for him (make up a socket to read 2708 as a 2716). Thanks again! dwayne Dwayne Reid <RemoveMEdwaynerTakeThisOuTplanet.eon.net> Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax Celebrating 17 years of Engineering Innovation (1984 - 2001) * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Do NOT send unsolicited commercial email to this email address. This message neither grants consent to receive unsolicited commercial email nor is intended to solicit commercial email. -- http://www.piclist.com hint: To leave the PICList spamBeGonepiclist-unsubscribe-requestspamBeGonemitvma.mit.edu

Reading a 2708 is not a problem surely. I can understand having problems writing to a 2708 with modern programmers. So, why not forget transferring the program to a 2708 and transfer it to the low addresses of a 2716, 2732, 2764, 27128, 27256........ and convert the pinout using a board from Aries (if one exists) or wirewrap your own. On the other hand, if you are going to do that why stay with EPROM, you could substitute EEPROM or Flash. Regards Chris -- http://www.piclist.com hint: To leave the PICList TakeThisOuTpiclist-unsubscribe-requestEraseMEspam_OUTmitvma.mit.edu

>Some weeks ago I told David to call me back if my suggestions didn't >work for him (make up a socket to read 2708 as a 2716). If doing this then you should be able to make the programmer read it as a 2508 which was the single supply 1k version of the 2716. Intel could not call it a 2708 as that number was already used for the triple supply device you are dealing with. Reading as a 2508 will mean that you will not read the contents of the EPROM twice in the read cycle. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads