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 Microcontroller programmer for MC68HC705
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 Return to top of page · Post #: 1 · Written at 12:38:50 PM on 11 November 2019.
Ian Robertson's Gravatar
 Location: Belrose, NSW
 Member since 31 December 2015
 Member #: 1844
 Postcount: 1737

I know this might seem a bit new for this site but given the age of this mart and the way we collect junk I thought I'd ask.

What I need is a programmer that can write to a Motorola MC68HC705C8A in PLCC. This is a OTP Eprom based microcontroller. Not many general purpose programmers support this chip, which is strange since at one time it was the 2nd most popular microcontroller.

Why do I need it? Many years ago I built some factory test jigs using this part and I now need to make some more. The code is complex and I don't feel inclined to try to port it to something else.

Buy, swap, rent or borrow, doesn't matter.


 Return to top of page · Post #: 2 · Written at 3:22:00 PM on 11 November 2019.
GTC's avatar
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 5750

This guy went the DIY route: http://www.opus131.com/ijs/c8a/

 Return to top of page · Post #: 3 · Written at 5:20:29 PM on 11 November 2019.
Ian Robertson's Gravatar
 Location: Belrose, NSW
 Member since 31 December 2015
 Member #: 1844
 Postcount: 1737

Yes, I recall that part has a serial bootloader and so it can effectively program itself. There was an appnote to that effect.

Way back in the 80s, we used to program them from Eproms on a jig that looked a lot like that one.

Problem is, this one's PLCC so I'll have to make a board. It might come to that. I hope I don't have to, it hardly seems worth it for a handful of chips.

 Return to top of page · Post #: 4 · Written at 5:01:19 PM on 3 December 2019.
Frank F's Gravatar
 Location: Brunswick, VIC
 Member since 3 May 2017
 Member #: 2100
 Postcount: 36

Hi Ian,

I have a Labtool 48 programmer sitting in a draw that I used to use for programming 68HC705s. The only problems I see for programming your chips is that the programmer code won't run on anything past Windows 95 and you need a parallel port to run it. I may have an old laptop that would do the job but none of it has run in years.

I do have a 44 pin PLCC adapter but I am not sure if it is compatible with the 68HC705C8A. There is also a stand alone programmer somewhere that copies the contents of an EPROM into the chips as well. I am just not sure where that is at the moment.

I will open my email up so that you can contact me directly.

Regards, Frank.

 Return to top of page · Post #: 5 · Written at 8:06:08 PM on 3 December 2019.
Ian Robertson's Gravatar
 Location: Belrose, NSW
 Member since 31 December 2015
 Member #: 1844
 Postcount: 1737

Thanks Frank. We used to have one of those. I still have several machines with real printer ports, to support a desktop mill I have.

Not so urgent now, I found some boards in a garage cleanup that have what I need on them, already programmed. So my 10 test jigs are now finished, once a couple of toggle switches arrive.

I'll email you.

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