HP Forum Archive 19

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Technical question; HP-41CV logic PCA Message #1 Posted by Geoff Quickfall on 19 July 2009, 1:59 p.m. Pictured above is the Logic PCA from a fullnut HP41-CV circa 1984. I have the manual for the HP-41C of which there are similarities. However I am trying to identify specific chips. INSCRIPTION YELLOW LABEL TYPE? ILE 906 A ROM ILE 907 ILE 908 ILE 703 B DISPLAY ILE 704 ILE 705 RAYT8306 C POWER SUPPLY N/A D CPU N/A E PEIZO TRANSDUCER Do I have A, B, and C correct? Cheers, Geoff edited to correct the CX reference . Edited: 19 July 2009, 8:42 p.m. after one or more responses were posted

Re: Technical question; HP-41CX logic PCA Message #2 Posted by Monte Dalrymple on 19 July 2009, 3:36 p.m., in response to message #1 by Geoff Quickfall B are the data storage (RAM) devices. Everything else is correct. Monte

Re: Technical question; HP-41CX logic PCA Message #3 Posted by Geoff Quickfall on 19 July 2009, 3:46 p.m., in response to message #2 by Monte Dalrymple Thanks Monte!

Re: Technical question; HP-41CX logic PCA Message #4 Posted by Monte Dalrymple on 21 July 2009, 7:44 p.m., in response to message #3 by Geoff Quickfall My pleasure. I've been staring at (and carefully measuring dimensions) of exactly this board for a couple of weeks. It's a marvel of miniaturization given the technology of the day. I especially like the capacitors mounted sideways, and on later versions the stacked 8-pin DIPs. Trying to squeeze an FPGA, a CPLD, a Flash memory and a static RAM, plus power supply and voltage translation circuitry on a board with these physical dimensions is "an interesting intellectual exercise" to say the least. Finding capacitors and an inductor that met the height restriction was a royal pain. Monte

Re: Technical question; HP-41CX logic PCA Message #5 Posted by Randy on 19 July 2009, 7:52 p.m., in response to message #1 by Geoff Quickfall That is not a CX board, it is a either a C or CV as the board part number (on opposite this view) is 5081-5563. There were a total of six different board layouts used in the life cycle of the 41, this was the fifth variant. The next board in sequence was 5081-5564 which was the only CX capable board. It was also used for the C and CV variants by installing the corresponding ROM and D/S parts. The CX added the timer IC 1LF6-0001.

OOOPS, sorry, it is a CV logic PCA... Message #6 Posted by Geoff Quickfall on 19 July 2009, 8:41 p.m., in response to message #5 by Randy Got my photos mixed up! I was working on a CX halfnut board when I typed the posting and I meant to say CV but CX was stuck in my head, REALLY ;-) Thanks Randy, Cheers, Geoff Edited: 19 July 2009, 8:43 p.m.

Re: OOOPS, sorry, it is a CV logic PCA... Message #7 Posted by Etienne Victoria on 20 July 2009, 12:48 a.m., in response to message #6 by Geoff Quickfall Hi Geoff, Diego Diaz has a nice page showing the successive CPU boards on his Clonix-41 website This can be helpful identifying boards & components. Cheers Etienne Edited: 20 July 2009, 12:48 a.m.

Re: OOOPS, sorry, it is a CV logic PCA... Message #8 Posted by Geoff Quickfall on 20 July 2009, 1:47 a.m., in response to message #7 by Etienne Victoria There are no coincidences, I was just on my way to Deigos site to copy his I/O-assembly flex-PCB pad instructions and thought to visit here first. So coincidence? off to Deigos, Cheers, Geoff The only manual I have is of the original HP-41C with screwed down logic PCA.

Re: Technical question; HP-41CV logic PCA Message #9 Posted by Eric Smith on 21 July 2009, 7:31 p.m., in response to message #1 by Geoff Quickfall FYI, the RAYT8306 line on the ceramic chip C is the vendor and date code, not the part number. The part number is the on first line, probably 1820-0953. The -1 suffix is most likely a minor manufacturing variation such as the case type, as any significant functional change would have resulted in a new part number assignment. Earlier 41s used the 1820-0566.

Re: Technical question; HP-41CV logic PCA Message #10 Posted by Randy on 21 July 2009, 8:12 p.m., in response to message #9 by Eric Smith The 1820-0953 replaced the original 1820-0566. The new part eliminated two resistors, R2 (100k) and R3 (1m) which were moved onto the die. The parts are otherwise interchangeable, so long as the resistor issue is addressed with the swap.

Thanks guys, thanks to Randy I am Message #11 Posted by Geoff Quickfall on 22 July 2009, 1:07 a.m., in response to message #10 by Randy digging up my hp 41C service manual and digging through the PCAs I have. Eric, some of us have bad eyesight and I thought the brand name would be easier to see as opposed to the discriptive label. Thanks for the help. Cheers, Geoff

Re: Thanks guys, thanks to Randy I am Message #12 Posted by Eric Smith on 22 July 2009, 1:22 a.m., in response to message #11 by Geoff Quickfall Quote: Eric, some of us have bad eyesight I'm one of 'em.

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