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HP-71b CMT-64E Eprom - Whats under the black goop ?
03-19-2020, 03:00 AM
Post: #21
RE: HP-71b CMT-64E Eprom - Whats under the black goop ?
(03-19-2020 01:22 AM)mfleming Wrote:  
(03-18-2020 06:10 PM)Ken S Wrote:  I saw that and will bid on it. A while back I picked up one with the 32k ram and a half dozen burned eproms so could use those with this on one of my 71s.

Everyone here who doesn't have this on their watch list raise their hand so I know who the other 14 of you are. Kidding aside, how difficult would it be to reproduce such a module? Though there is surely some custom logic involved, microprocessors and FPGAs have become quite small, if somewhat allergic to 5V.

The chip carrier and logic are probably not too bad, the board looks pretty simple, but isn't the set of sockets to accept the 11 pins in the Card Reader port somewhat unusual, and presumably hard to find?

--Bob Prosperi
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03-19-2020, 03:12 AM
Post: #22
RE: HP-71b CMT-64E Eprom - Whats under the black goop ?
(03-19-2020 03:00 AM)rprosperi Wrote:  
(03-19-2020 01:22 AM)mfleming Wrote:  Everyone here who doesn't have this on their watch list raise their hand so I know who the other 14 of you are. Kidding aside, how difficult would it be to reproduce such a module? Though there is surely some custom logic involved, microprocessors and FPGAs have become quite small, if somewhat allergic to 5V.

The chip carrier and logic are probably not too bad, the board looks pretty simple, but isn't the set of sockets to accept the 11 pins in the Card Reader port somewhat unusual, and presumably hard to find?

Not at all. I have the P/N from the FRAM71B BOM. 1001 in stock at Digi-Key.

https://www.digikey.com/product-detail/e...ND/2264450

Dave
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03-19-2020, 04:49 AM
Post: #23
RE: HP-71b CMT-64E Eprom - Whats under the black goop ?
Now that's pretty neat. I didn't look closely at the photos and just assumed plated through holes like the Classic and Woodstock connections. Looks like an IC under the socket? Forgot about the FRAM board. Any other parts on the BOM still stocked and available?

Remember kids, "In a democracy, you get the government you deserve."
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03-19-2020, 05:33 AM
Post: #24
RE: HP-71b CMT-64E Eprom - Whats under the black goop ?
(03-19-2020 04:49 AM)mfleming Wrote:  Now that's pretty neat. I didn't look closely at the photos and just assumed plated through holes like the Classic and Woodstock connections. Looks like an IC under the socket? Forgot about the FRAM board. Any other parts on the BOM still stocked and available?

The IC under the socket is most likely a 1LJ4.

The FRAM71B FPGA and FRAM are still active and available. None of the other parts are special.
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03-19-2020, 07:55 AM
Post: #25
RE: HP-71b CMT-64E Eprom - Whats under the black goop ?
(03-19-2020 12:16 AM)Dave Frederickson Wrote:  
(03-18-2020 03:30 PM)J-F Garnier Wrote:  To make the ROM image from a IRAM port, I recommend to use the ROMCOPY function to first create a ROM file on a mass-storage unit, then to load it back (again with ROMCOPY).
This may not be needed for ROMs with only LEX files, but it is mandatory for ROMs that include BASIC files, to make sure the chaining/compilation process is correctly done. This is something we discussed in the past, but I can't find the reference right now.

The CMT tool Port Generate Checksum, PTGENC$ described in Step 10 on p.11 of the CMT-71-P01 manual will chain all files that need to be chained.

Dave

Oh yes, you're right. Actually, my experience is mainly with the HHP EPROM module, for which I (at the time) had only the ROMCOPY as a tool.
I programmed CMT modules much much later, when I got a CMT programmer and a few modules (yes, I'm one of the 7 :-)

J-F
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03-19-2020, 09:14 AM (This post was last modified: 03-19-2020 09:20 AM by KimH.)
Post: #26
RE: HP-71b CMT-64E Eprom - Whats under the black goop ?
That is an excellent contribution Bob - thanks a lot for this!

Now all I need is the rain Smile

(03-19-2020 01:11 AM)rprosperi Wrote:  
(03-18-2020 04:38 PM)rprosperi Wrote:  I have programs (FORTH & BASIC) for generating the proper image, sent to a PC to burn the EPROM chip, just waiting for confirmation to post them here, as it was a collaboration with someone else. Did not think there would be much of an audience, as it's somewhat of a niche within a niche. Smile

While not real complex, it's not as straightforward as it seems.

I created a new thread (here) to post the programs for creating the image files, to avoid further hijacking of the original Black goop topic.
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03-19-2020, 10:13 AM
Post: #27
RE: HP-71b CMT-64E Eprom - Whats under the black goop ?
(03-19-2020 05:33 AM)Dave Frederickson Wrote:  
(03-19-2020 04:49 AM)mfleming Wrote:  Now that's pretty neat. I didn't look closely at the photos and just assumed plated through holes like the Classic and Woodstock connections. Looks like an IC under the socket? Forgot about the FRAM board. Any other parts on the BOM still stocked and available?

The IC under the socket is most likely a 1LJ4.

The FRAM71B FPGA and FRAM are still active and available. None of the other parts are special.

Thanks Dave and all. I am in awe of the knowledge of this group.

My motivation for the original post was to establish what was beneath the goop. Looks like a 1LJ4. Obviously it would be great to know whether the CMT eprom module could be programmed without cracking open the module itself. Not sure how the Fram71 can assist with this ? I am going to try and program an open module in circuit, unless thats a bad idea?

If only the Fram71 was still in production Smile

Cheers

Richard
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03-19-2020, 01:06 PM
Post: #28
RE: HP-71b CMT-64E Eprom - Whats under the black goop ?
(03-19-2020 03:12 AM)Dave Frederickson Wrote:  Not at all. I have the P/N from the FRAM71B BOM. 1001 in stock at Digi-Key.

https://www.digikey.com/product-detail/e...ND/2264450

Dave

Yeah, that was a stupid comment, as I've purchased 3 FRAM71 boards in recent years, each of which uses these sockets. Dumb, dumb, dumb...

--Bob Prosperi
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