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Panasonic HHC

NeXT

NeXT

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Oct 21, 2008
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Location
Kamloops, BC, Canada
Someone at the VCF Consignment was selling three units in varying condition and I drew the short straw. :(
They all seem like they were from a portable programming system for GE radios and mobile telephones ( https://www.hallelectronics.com/getech/prog4.htm ) so they all came with the computer and 8k ram, the I/O bus expander, the printer/cassette option, an expansion ROM module and the programming jig which almost looks like an EPROM programmer if you squint hard enough. There's also a plastic tray that holds everything and is annoyingly just a little too large for me to fit into a standard briefcase, but mine has a Bell Canada asset tag! The lucky folks also got with theirs additional manuals and cables and even schematics which I asked if they could scan them. Mine turned out to have pretty bad battery damage that's eaten over a dozen landing pads for the LCD's zebra strip and possibly the LCD itself. I went over the rest of the boards and after a vinegar wash they cleaned up a bit and I don't see anything immediately bad, but without a screen the whole thing's kinda dud. I can probably find another unit but a lot of the online mentions seem to say it was almost exclusively a product that requires you to make custom application ROMs for it. I can't find any software available online to make it much more useful. There is mention of a Microsoft BASIC ROM but I've not found dumps of the option ROMs either.
 
I have another unit hopefully on order and arriving in two weeks.
So the catch is my has an "8" printed on the front and the replacement does not. Since it seems there was 2K, 4K and 8K models I'm assuming the damaged one is an 8K model and this replacement is a base 2K. I'm hung on if I should try swapping the ram or swapping the entire LCD/keypad board in order to build one working unit. Does anyone have advice here?
 
I am guessing that you have already received your replacement, I looked inside one of my 8K units, and if the board with the memory is undamaged in your 8K model it might be easiest to swap it over.

There is also a battery pack in the printer module, it is not real easy to get to and is in the middle of the unit so if it has leaked there is a high probability it will have done some damage.

One thing you will find is the hardware in these units is to say the least unusual. I have some of the language compiler ROMs but there is a catch, they are not an industry standard ROM. You will find that a lot of the ROM "capsules" that you will find in the ex insurance company units are Motorola 8K 68766 EPROMs that are mounted upside down and when you dig into it you will find that the chip enable pin is connected to one of the address lines. This works because the ROMs are enabled and disabled by turning power off and on, which leads to the ROM modules for the compilers, they are 16K modules so they have an address line where the chip enble line would be on the EPROMs.

There was a discussion about making a replacement using modern components on the forums of hpmuseum.org, look for "Panasonic HHC ROM capsules" I believe they where successful in recreating them, but I did not follow it closely since I have the compilier modules. Since you have one of the GE programming kit there may be a better solution for you, one of the custom modules that should be with it should be an EPROM module, and I suspect that you could burn an image into and EPROM and install it in there, it one of those things I meant to try but have not got around to it. BTW the GE kit where originall packed into a nice solid case, that is the way mine came. Along with the 8K HHC that came with it I have one other 8K and two 2K models I have also scrapped at least one due to battery leakage damage.

Paul.
 
Well the fact that it responds to keypresses, beeps when it should and seems to respond to the on/off button tells me that yes, swapping the CPU board to the 4K replacement I found will work, however it seems I've gotten so fond of how clean the 4K unit was I decided to leaave it alone, so I goess the next time I find one that has a good keypad/display board I'll swap that in.

I was warned about the battery in the printer. It was leaking but nowhere near as bad as it was inside the computer. They have been removed. I guess if the ROMs are "special" in their own way I'm rapidly losing interest in this because that then puts in about the same usefulness as the Tandy 100. Yes I do have the ROM box and yes it already has a few EPROMs in it already so that is however an alternate method I can use if I want.
 
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