need help Programming '165 Memcal

[rrauscher at nni.com]

A rapidly flashing ses light indicates that the eprom runs,
however, the cksum does not match. A steady ses light means
that the eprom is totally out to lunch.

BobR.

>Here's a picture of two of them... the newer memcal is on the left...
>
>http://home.flash.net/~marcho/twochips.jpg
>
>yeah, when I attempted to program them as 256, I just put the bin in there

>twice so that it started at 0000 and then repeated at 4000.
>
>Craig M.
>
>-----Original Message-----
>From: owner-gmecm at diy-efi.org [mailto:owner-gmecm at diy-efi.org]On Behalf
>Of Richard Wakeling
>Sent: Sunday, December 10, 2000 11:33 PM
>To: gmecm at diy-efi.org
>Subject: Re: need help Programming '165 Memcal
>
>
>Hi Craig,
>    What markings (numbers/letters) are on your eproms? I will try and
>Identify
>whether they are 128 or 256 types. If they are 256 types and you want to
>prog a
>128k bin it must be put in the lower half if viewing with a hex editor. To

>do
>this load the 128k bin at 4000 and the end will fall automatically at 7FFF

>
>Cheers Richard.
>
>Craig Marcho wrote:
>
>> Well,
>>
>> I tried to program a chip for an '86 Corvette, and it didn't work. Maybe

>> somebody can tell me what I've done wrong and steer me in the right
>> direction.
>>
>> I've got three memcals for this application, one fairly old and original,

>> and two new ones from GM that I got a couple weeks ago. I read them all
>fine
>> as 27C128A. Then I erased them, (the new ones seemed to take a long time

>to
>> erase...). I changed what I needed to in the code, and then went to
>program.
>> I programmed one of the new ones first, as 27C128A. Put it in the car, and

>> it didn't work. The car ran, but the check engine light flashed a bunch
>and
>> the idle was very erratic. So I pulled the chip, and erased it. I had
>> another new GM chip so on a hunch I read it as a 256 and it had the code

>in
>> there twice, so I'm guessing that the new chips were 256k eproms. I erase

>> the one I programmed and tried to program it as 27C256A. The Needham's EMP

>> software spit back at me as soon as I started programming. It didn't
>program
>> correctly and quit. I had to erase it again. I then tried as a 27C256 and

>> same thing, complained right away and didn't program. I programmed the
>older
>> chip as a 27C128A and it programmed nicely, but with the same results on

>the
>> car... check engine light and erratic idle. I have no clue what these
>chips
>> are, or what voltage they should be programmed. If I tried to program a
>> 27C256A chip at 27C256 voltage did I fry it? Should I just remove the
>delco
>> eprom and buy some eproms that I can program and stick them on the memcal?

>> I've done hundreds of 2732 chips with no problems at all, but haven't had

>> any experience with these chips in the memcals and am not having much
>> success. Please help me out here, let me know what I should try....
>>
>> Thanks for any help!
>>
>> Craig M.
>>
>> --------------------------------------------------------------------------

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