|Re: MLDL 6E O.S. source|
Message #3 Posted by Donald Leonard on 13 June 2003, 3:01 p.m.,
in response to message #2 by Meindert Kuipers
It's a huge case (8 1/2" X 5 1/4" X 3") with a silk screened nomenclature over a painted silver/grey front panel. Interior circuitry has 3 daughter boards of discreat CD4000 series CMOS devices mounted through connectors to a buss board. The front panel contains the 4K EPROM SET (2732 & 2708), a RAM switch marked EIN/1ma at the top and AUS/.005ma at the bottom. I suspect that this switches the 4.5V battery backup out of the circuit when the MLDL is connected to the HP-41. Also on the front panel is a 31 pin test connector marked Port XFFF, sub divided into input 0-9, WPORT, ENOUT, XS, X, MS, and a miniture Digiswitch for 8K RAM Address select, with a 'X2' printed next to the digit.
This unit appears to be a corporate R&D/development unit rather than a home made/hobbiest unit. Some serious cost and preparation time went into the construction of this box. And, the MLDL 6E routine/function list is unusual as well. Besides the sample routine list given earlier, there are a total of 23, one of which is most likely used for developing commercial modules only (CHKSUM) as the HP-41 does not check for a checksum. This box also is from a european source as the HP-41 turns ON with european digit separators/radix when the MLDL is connected.
I would dearly love to find out about these routines as I have a suspision that they are a powerful support to the David Assembler also contained within the same EPROM set, not seperate. Don