HP Forum Archive 14

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MLDL2000: Basic functions work! Message #1 Posted by Meindert Kuipers on 11 Jan 2004, 3:44 p.m. Good news: the basic functionality for the MLDL2000 is now working. Tested features are now: - uploading of ROM images to SRAM from a PC - programming ROM images in FLASH eprom from a PC - using multiple images from both FLASH and SRAM on the HP41 - switching between sets of roms using an external switch Still to be tested: - Bank Switching - Correct power-on behaviour (is still a bit shaky still) I am currently using a parallel I/O interface for uploading ROMimages through a USB interface. This turned out to be very slow (about 1 min 30 sec for a 4K ROM to SRAM, and over 10 minutes for programming a 4K ROM to FLASH). The cause of this is known and I will modify the I/O interface and use a different USB controller. Finally I am getting there, and I hope to be starting PCB layout for the beta units with two weeks now! Meindert

Re: MLDL2000: Basic functions work! Message #2 Posted by Gene on 11 Jan 2004, 5:27 p.m., in response to message #1 by Meindert Kuipers Great News! Be sure to keep us informed! I have a working 41 card reader that will be sacrificed when you say it is ready! I can't wait! Gene

Re: MLDL2000: Basic functions work! Message #3 Posted by Diego Diaz on 12 Jan 2004, 3:13 a.m., in response to message #2 by Gene Hi Meindert, That's a good point indeed! As you already know, my CR enclosure is ready to hold these little wonder of yours... Keep up the good work! Cheers Diego.

Re: MLDL2000: Basic functions work! Message #4 Posted by Massimo (Italy) on 12 Jan 2004, 4:01 a.m., in response to message #3 by Diego Diaz Hello Diego, a CR enclosure? Does this reminds me of something? <wink wink nudge nudge> Keep up the good work you both! Massimo

Re: MLDL2000: Basic functions work! Message #5 Posted by Wayne Brown on 12 Jan 2004, 11:36 a.m., in response to message #2 by Gene Quote: I have a working 41 card reader that will be sacrificed when you say it is ready! Gene, I'm sure I don't have to tell you this, but for others who might be considering the same thing: PLEASE save the parts you remove from the card reader! I don't need any repair parts at the moment (my own reader was repaired with a small part donated by Luiz Vieira some time ago), but there must be people out there who need a new motor, or magnetic head, or leaf switches, or something. In fact I'd encourage anyone who disassembles a module or other component for one of these projects to save any unused pieces and make them available for others who might need them. When I think of all the empty module shells that must have been thrown away years ago when people were homebrewing double modules and the like... it's enough to make a person cry!

Re: MLDL2000: Basic functions work! Message #6 Posted by Donald1800 on 12 Jan 2004, 10:42 p.m., in response to message #1 by Meindert Kuipers This IS good news. I too have an extra Card Reader ready and waiting for this replacement for my "craped-out" MLDL. I crave working again in M-Code. I thought, however, that the final system would have software select of active or read enabled lower/upper 4K blocks instead of mechanical switching. Don

Re: MLDL2000: Basic functions work! Message #7 Posted by Meindert Kuipers on 13 Jan 2004, 5:09 a.m., in response to message #6 by Donald1800 Don, Software switching will be possible by using a special Mcode program. Mechanical switching is available to be completely independent of any of these special programs an be able to work with standard ROMs only. Without the switches an incorrect programming of the ROM configuration would require connecting the MLDL to a PC to recover. Meindert

Re: MLDL2000: Basic functions work! Message #8 Posted by Donald1800 on 14 Jan 2004, 1:17 a.m., in response to message #7 by Meindert Kuipers Mechanical switching is O.K. - I just didn't think that it would be physically practical to have 8 4K blocks in the HP41 ports with their own set of digital rotary switches covering the entire memory map of the MLDL2000 and still fit inside the Card Reader. I obviously missed something. Having mech. switches visable does make it a lot easier to instantly see what starting address is assigned to each U/L port block. Don

Re: MLDL2000: Basic functions work! Message #9 Posted by Meindert Kuipers on 14 Jan 2004, 2:44 a.m., in response to message #8 by Donald1800 Let me explain how the MLDL2000 works in this respect: 63 ROM images can be loaded in FLASH and 16 images in SRAM. in both types of memory there are 4 tables (the Settings Registers, 8 of these in total) that determine which image is plugged in which port (and in which bank as well), and also indicate if the image in in SRAM or FLASH and if it is writeable MLDL/RAM memory. The tables in SRAM are easily modified of course. These Settings Registers are the only way to move modules around. The mechanical switches (there will be 3 or 4) determine which of the tables is active and allow you to switch between different 'machines'. One setting could be for math calculations, with the Advantage ROM, CCD and such, another for Mcode development with CCD, HEPAX, DAVID Assembler etc. (Note that HEPAX is not supported yet). MBA types could have their favorite set with financial modules. Retro geeks with PPC ROM, MATH-1A, STAT, etc .... Meindert

Re: MLDL2000: Basic functions work! Message #10 Posted by Donald1800 on 14 Jan 2004, 3:19 p.m., in response to message #9 by Meindert Kuipers Thank you for the clarification. And yes, that looks like a good compromise between hardware and software. This is really looking good. Don

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