The Museum of HP Calculators

HP Forum Archive 13

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MLDL2000 update
Message #1 Posted by Meindert Kuipers on 25 June 2003, 6:36 a.m.

Just a quick update from my side about the MLDL2000. I was hoping to have some real good news this week, but I have made a terrible mistake in soldering the wiring for the SRAM/FLASH protoboard and that will cost me at least two nights to redo that work and get a new breadboard proto up and running.

What I am doing now is testing a setup with SRAM and verifying two things:

1. WROM functionality

2. Operation of the 3-cycle memory access to SRAM: write L8 word, read packed U2 word, modify U2 word, and writeback U2 word. The last part is really critical for the intended operation of the MLDL.

Above steps are potentially functional before or during the weekend, unless is simply does not work. Simulations however have shown excellent behaviour of the MLDL in this respect and has helped me to correct some other mistakes in the VHDL code.

If the above is working I will start on the I/O interface, critical for programming the FLASH memory (this cannot be done from the HP41). Most effort will be in the software on the PC. For those interested, the I/O interface is implemented using a not very expensive (around EUR 60) USB to parallel interface print. This actually means that the MLDL2000 will offer an optional USB interface! This is done with the USB V1.2 plus product, see It comes with drivers and an API and I have to make some software (using Delphi in my case) to be able to interface with the memory devices on the MLDL2000.

In the meantime, I have been working on the specifications, including definition of the I/O interface. A new version of this should be online in a week or two with renewed pictures of my developmnet environment and museum at

When the I/O interface is settled and verified, I will be ready to start working on the PCB and get some real hardware out. There will most certainly be a beta-test program but some details will have to be sorted out. I am targeting to have beta-units out around mid-september (conference time remember) but that timing is challenging.

A usual, I will let you all know when further developments are taking place! Do not hesitate to contact me for any questions. I have received many warming encouragements, and it appears that I have put some other fanatics to work on hardware projects as well.


Re: MLDL2000 update
Message #2 Posted by jeff on 25 June 2003, 1:33 p.m.,
in response to message #1 by Meindert Kuipers

Excellent work Meindert! I look forward to your next update. Jeff

Re: MLDL2000 update
Message #3 Posted by Gordon Dyer on 25 June 2003, 5:42 p.m.,
in response to message #1 by Meindert Kuipers

Great work! keep it going.
I am waiting to see the finished product on your web site...

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