Sharp PC7000/7100 Expansion chassis recreation

[BlaBla1985]

The easiest way to connect a Gotek to a PC 7000 would be with something like this:
Floppy adapter
basicly, a little board that changes the edge connector to a 34 pin connector. I have not tried this though, i have only build a Gotek into a PC7100 (which has a standard 34 pin to card edge socket cable for it's floppy drive, not the special 3 connectors to card edge socket like the PC 7000).
On the PC 7100 i had to jumper the Gotek to be DS0 for the A drive.

As for an MDA card working in a the board, I don't know. I don't own a MDA card so I can't test it. But i have tried both CGA and EGA cards and neither works, so my guess would be that MDA doesn't work either.

 

[Patojanet]

The easiest way to connect a Gotek to a PC 7000 would be with something like this:
Floppy adapter
basicly, a little board that changes the edge connector to a 34 pin connector. I have not tried this though, i have only build a Gotek into a PC7100 (which has a standard 34 pin to card edge socket cable for it's floppy drive, not the special 3 connectors to card edge socket like the PC 7000).
On the PC 7100 i had to jumper the Gotek to be DS0 for the A drive.

As for an MDA card working in a the board, I don't know. I don't own a MDA card so I can't test it. But i have tried both CGA and EGA cards and neither works, so my guess would be that MDA doesn't work either.

Thanks for the info, but do you know of a way to force monochrome video output from the PC7000? Kind regards

 

[BlaBla1985]

Looking at a spare motherboard, from a machine with a destroyed case, the video of the build in screen seems to come from the top large square chip near the connector for the screen. I doubt any usefull video can be extracted from there.

 

[BlaBla1985]

I had wanted to do this much earlier... but for some reason I had misplaced the bracket that holds the original Hardcard inside the PC7100. But, it resurfaced recently and I've finally tried to mount one of my PCB's inside the bracked into the computer. This gives it an internal hard drive again, a little slower then the original but with a much larger capacity.




The screen tilt mechanism made it a bit of a squeeze to get everything in there, the first time I tried to close everything up the USB stick would keep the screen from folding in again. It is fitting fine now. These machines have very little spare room inside them.



The ribbon cable goes over the motherboard into the expansion connector, on the right side of the motherboard is the gotek I use to boot the system. The wiring of this machine is a mess of my own making, thanks to all sorts of solutions i've tried to get a hard disk like experience back into the machine. To the right of the gotek is a switch that switches the A and B drive (gotek is normally A while the floppy drive is B). There is also a mini din 6 port that can power a parallel port CF card reader.





And now it boots straight into the C drive, although I still need a floppy disk (or a bootable gotek image) with the driver for the ISA to USB hard. It works pretty well.

 

[fr4nk]

Thanks for this. My wife brought home a PC-7000 that she saw sitting by a dumpster in the rain! No printer or HDD unit, naturally. Did several jumper-wire trace repairs where the plastic supports had broken through the keyboard PCB... and it works 100%! It smells like high voltage when it's been running a while, if you know what I mean. Ozone? Any advice on that is welcome.

I left it in stock condition so far, my Goteks are in use elsewhere. Hoping to find a use for the empty internal expansion and HDD ports; nibbling to a Zip drive through the parallel port is slow and, of course, not a bootable device.

 

[seat safety switch]

What a lucky find (both partner and Sharp!) I would suspect the EL backlight circuit, or low-ESR caps in the power supply if it's a later one (post-87, early 90s production.) Do you hear any unpleasant faint whining noises?

I've had a bunch of Nichicon PX/PF/PMs vomit in the last few years in this class of "inexpensive tiny Japanese computers" - usually Brother and NEC word processors, but I wouldn't be surprised to find those inside this either.

 

[BlaBla1985]

I left it in stock condition so far, my Goteks are in use elsewhere. Hoping to find a use for the empty internal expansion and HDD ports; nibbling to a Zip drive through the parallel port is slow and, of course, not a bootable device.

There isn't really much internal expansion in the PC7000, apart from the 2 slots for a CGA card and a modem. The double floppy drive takes up most of the internal space inside the computer. A ZIP drive works if you use a special driver (palm zip or something, I was not really a fan of it as it needs specially formatted ZIP disks) A NEC V30 processor would fix that but my Sharp PC7100 did not want to work with a V30, only the 8086 it came with. I tried the V30 chip in another XT clone it worked fine it that.
Some parallel compact flash readers work too... but it's pretty slow.

If you want to connect a Gotek, you need to set the jumpers slightly different then with a normal PC. They follow the Shugart standard for drive selection instead of what the PC does with a twisted cable. If you use a tool from NFormat you can use Gotek images of up to 2,5ish MB.

On the Ozone smell... aside from the screen backlight and the PSU I don't think there is any real high voltage in there.

Finding one by the side of the road is a pretty neat find.