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Sharp PC7000/7100 Expansion chassis recreation

BlaBla1985

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Zuid Holland, The Netherlands
This is just a quick start, i'll have to do a proper write up soon, but for the past 5-ish years i've been trying to make a copy of the CE700E. This is the larger of the 2 external expansion chassis for the Sharp PC7000 and 7100 portable computers.

Yesterday evening i finaly got it working. And by working i mean i was able to use one of those ISA to USB boards as mass storage on a PC7100. My schematics are still a mess with some dumb and silly errors in it. I still need a floppy or a gotek to boot the machine and load the ISA to USB driver (thanks to FreddyV for the improved driver), so it's not a fully booting hard drive.

Here are some quick shots taken during the tests, I'll try to get more details out over the weekend, as i have to go to work in a few minutes.

Overview.JPG
driver.JPG

diskspeed.JPG

Closeup1.JPG
Closeup2.JPG
 

pearce_jj

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@BlaBla1985 - congrats on getting this working. Have you done anything to get that LCD working so clearly? I have a couple of machines here with that type of display - Tandy 1400 and Yamaha C1 - but both are verging in illegible as the contrast is so bad. TBH, I don't remember the Tandy (which I had from new) ever being as clear as that. Certainly, it never looked as advertised!
 

twolazy

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I have a similar project in mind soon, using an old word processor... Buddy has an old PC7000 thats case is just cracked everywhere and not worth saving. Considering marrying the 2 somehow. Height is a lil shorter but not much, and display seems about the right size.

A sharp like this... Will be following this thread closely! Would love a few isa slots!👍


The word processor... Hard part will be trying to merge the Sharp keyboard onto the Brother. Going to need to find someone with a big 3D printer maybe, or maybe I can make inserts I dunno, will worry about that bridge when I come to it. Have a tiny trackball I hacked off an old Dell XPi P90 laptop 2 decades ago, to work on an ps2/serial port that I wanted to use as well. Aiming for a nearly stock looking what could have been machine. Something unique (plus im kinda cheap and creative lol). :)

s-l1600.jpg


Will you be sharing the Gerbers or is it for sale once done or ?
 
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BlaBla1985

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@BlaBla1985 - congrats on getting this working. Have you done anything to get that LCD working so clearly? I have a couple of machines here with that type of display - Tandy 1400 and Yamaha C1 - but both are verging in illegible as the contrast is so bad. TBH, I don't remember the Tandy (which I had from new) ever being as clear as that. Certainly, it never looked as advertised!
Thanks, it's been an education in frustration but I'm quite happy it's working now. The display on the PC7100 is completly standard, it's set to it's highest brightness in the bios setup and set to inverse. The display of the PC7000 is a lot worse and far dimmer then this one. I still have to test the PC7000 with my board, but i don't think i have made a bootdisk yet with the ISA to USB drivers on it.
The PC7100 in the pictures boots from a Gotek that's hidden away in the back where the CGA option card goes.

I have a similar project in mind soon, using an old word processor... Buddy has an old PC7000 thats case is just cracked everywhere and not worth saving. Considering marrying the 2 somehow. Height is a lil shorter but not much, and display seems about the right size.

A sharp like this... Will be following this thread closely! Would love a few isa slots!👍


Will you be sharing the Gerbers or is it for sale once done or ?
While the ISA slots are standard, the Sharp portables are not completly IBM PC hardware compatable. Things like XT-IDE cards don't work (i believe anything with a custom rom not from original sharp expansions don't work) CGA/EGA cards don't work, as Sharp had a custom CGA card to use in the machines, same goes for modems and i think networking cards.
Serial/parallel card should work, but i have no -5/-12 Volts rails connected to this board and i think that's the reason i can't use those yet.

once i've ironed out most of the silly things from the schematics and so on i will probably just put them online for people to use. all i really did was redraw the schematic from the CE700E service manual, fixed a few mistakes in it using the boards from a real CE700E and ran an autorouter over the layout.

i do want to make the boards smaller and maybe even integrate the CH375 USB card to replace the Plus Development Hardcards in the PC7100, as there is really nothing else that works in these machines apart from some external parallel CF card readers.
 

BlaBla1985

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I made a bootdisk with the CH375 drivers and tried it on one of my PC7000. And it works on that machine aswell.


PC7000-0.JPG
PC7000-2.JPG

Although i'm quite happy with it working right now, i did allready try and design it to be smaller so it would fit on the Hardcard mount inside a PC7100 with room for the USB card. These are some WIP images of that, the connectors are not quite rightly positioned and it still has some footprint issues.
newboardwip.jpg
renderwip.jpg
This version would be around 10cm by 17cm (or around 4 by 7 inches, roughly).

I should have some good photo's of the original boards in the CE700E, but i have no idea where i stored them... I'll have to search for those or take some new ones. But this entire project is based on this.
IMG_3904a.JPG
and i'm really glad it can be shrunk down a lot.
 

seaken

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I was not sure where you were going to put that PC Board. But maybe now I see the Sharp Expansion Box under the PC-7100? Is that right? If so, it now makes sense for me. I looked on the internet but never saw a separate expansion box.

Nice project. Thanks for sharing.

Seaken
 

BlaBla1985

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I was not sure where you were going to put that PC Board. But maybe now I see the Sharp Expansion Box under the PC-7100? Is that right? If so, it now makes sense for me. I looked on the internet but never saw a separate expansion box.

Nice project. Thanks for sharing.

Seaken
the board in the pictures is just the first working prototype. really nothing more then a copy (down to the spacing of the IC's) of the original boards just to see if i could do a project like this. It's not really meant to be mounted anywhere yet.
The chassis is ungodly rare for some reason, took me years to find one on ebay.
I found the photo's of the original boards. inside the chassis are a powersupply that is controlled by the computer on top, an interface card, a backplane and a custom MFM controller with a 20MB harddrive.
The interface card:
interface.JPG
that connecter up top threw me for a loop while making the cable to my recreation. i would not have found that mistake without the original board.

The backplane:
backplane.JPG
The interface board plugs into the bottom connector, the custom MFMcard goes into the top pinheader. the isa bus on this backplane has it's own clock generator.

The MFM card:
MFMcontroller.JPG
i have not implemented this card in my design, as i doubt anyone has this card and not the rest of the expansion chassis... although the schematics are in the service manual.

the WIP design is actually meant to be installed in the empty space left when the hardcard in a PC7100 is removed. The hardcard is mounted in a metal bracket, so it should be reletivly easy to do. Instead of putting the ISA slots into the board directly i thing i will use IDC connectors and a short ribbon cable to an edge connector that can be attached to said ribbon cable (so the ISA card is lying flat on the bracked). i'm not quite sure where to put it in a PC7000 but i'll figure that out when i've finished the new board design and have some PCB's made.

it's really to bad these machines don't support costum roms, an XT IDE would be so convienent, but allas they don't work.
 

Getafix

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For clarity, in case I didn't understand this correctly. What you designed can be (eventually) put into a 3D printed case, hooked up with the ribbon cable and a PSU (or maybe powered by the PC?) and that will act as an external HD for anyone with a PC7000 or PC7100? Is that indeed what you built - something that acts like the interface card, backplane and MFM card, but for a USB stick "HD"? I know I'd be in the market for that alone, even if the device didn't have any ISA slots or any more functionality. Would love to add an HD to my PC7000.
 

BlaBla1985

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For clarity, in case I didn't understand this correctly. What you designed can be (eventually) put into a 3D printed case, hooked up with the ribbon cable and a PSU (or maybe powered by the PC?) and that will act as an external HD for anyone with a PC7000 or PC7100? Is that indeed what you built - something that acts like the interface card, backplane and MFM card, but for a USB stick "HD"? I know I'd be in the market for that alone, even if the device didn't have any ISA slots or any more functionality. Would love to add an HD to my PC7000.
mostly, like i said i have not included the MFM controller as i think it can only support the 20MB drive that comes with the original chassis. A lot of the Sharp's architecture is weirdly proprietary.
I'm only copying the interface card (basicly the adress decoding logic to hook the ISA bus up to the Sharp's expansion connector) and add the backplain and clock circuit to that. the ISA to USB board is one of those generic cards from China. It works as a hot swappable mass storage device, but it needs a driver to be loaded from either a bootdisk or a gotek. it more or less functions like one of those parallel port CF readers, but a lot faster.

but yeah, the currrent board has a +5 and +12 power input, so in theory it should work on the internal power supply. although i have it on an external supply now.
 

BlaBla1985

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The smaller board design is more or less finalized. Although i haven't made the gerbers yet, I tend to miss small errors if I do everything in rapid succesion. I've named the project "CE700minE", very original i know....
Here is a 3d render from KiCad:
CE700minErender.jpg
The triple pinheader is not supposed to be a pinheader, but my KiCad skills are very much at beginner level and i think i need to find some additional libraries. The idea is that the right 2 rows of pins are the same, so one can use either and IDC connector and a ribbon cable to a card edge socket (usefull inside the PC7000/7100) or a card edge socket (usefull for external chassis).
the original chassis powersupply is switched on via a signal from the PC's powersupply. this signal powers a relay in the chassis PSU. that signal is now near the power input pins at the top of the render.
i tried to put as many part numbers, values and orientations near the components as possible.

Here is also a screenshot of the board layout:
CE700minElayout.jpg

I was wondering about the best way of sharing this project once a good set of gerber files are made and i know the board is working, would just putting them here be usefull? or maybe start a github for it? this is very much new for me. I don't really want to start selling these, i barely have any freetime as it is.
 

BlaBla1985

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Quick update, i got the new prototype boards. Really happy with them. This gives me something to do this weekend.

NewBoard.JPG
It's quite a bit smaller then the first working prototype, it should fit really neatly inside the PC7100's hardcard bracket, with space for an ISA to USB card:

Comparison.JPG
 

BlaBla1985

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One of the new boards is finished and tested, and works like a charm. I intend to build 2 of them, one to put into a project box as an external option for the PC7000's I own. and one to build into my original PC7100 which kickstarted this project (the hunt for a new internal "harddisk") and my collection of vintage computers.

the only thing this setup doesn't officialy do is starting from the USB drive, it boots from a Gotek drive and then switches to C:\ once the driver has loaded and initialized the flashdrive. It can also start from a normal floppy. I've seen the massive thread on the forums about booting from the USB drive and that would be really cool, but these Sharp machines don't like costum roms... otherwise, XT-IDE would've been a good option for this aswell. The XT-IDE does work in the PC7200.

Overview.JPG

Closeup.JPG

Booting.JPG

Working.JPG

Testing.JPG
 

Ruud

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Things like XT-IDE cards don't work (i believe anything with a custom rom not from original sharp expansions don't work)
I assume the ISA bus has all address lines and an external ROM, like the one of XTIDE, can be read. If so, then IMHO it is the BIOS of the Sharp that prohibits that an external ROM starts up. An IBM looks for these external ROMs and if certain conditions are forfilled, the ROM is started. But if the Sharp's BIOS is lacking this function or will only start up ROMs made by Sharp, then the only solution that comes to my mind is changing the BIOS. Not easy, but not impossible either.

I am interested in your card. I'm even more interested in the older one, the one with three ISA slots. Ik hoor het wel :)
 

BlaBla1985

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I assume the ISA bus has all address lines and an external ROM, like the one of XTIDE, can be read. If so, then IMHO it is the BIOS of the Sharp that prohibits that an external ROM starts up.
This is from the originals service manual (which also provided the base schematics this entire project is based on).
screenshot.jpg

1 thing that this document claims doesn't work but does work: you can use a serial/parallel card (but not the gameport connector, that won't work) as long as you can set them via jumpers to be serial port 2/ parallel port 2 (i've tried a third serial port but that won't work).
i have tried an XT-IDE card, but it just seems to ignore it. no splashsreen or anything, it will simply ask for a bootdisk and then error out.

other thing that don't work, Adlib sound cards... for some reason, they give some sound but it's a few notes from time to time. my guess for that is because the expansion board runs at 4,77Mhz always (it has it's own clock section) and the computer can run on 7,something and 4,77Mhz.
Also, the systems are isolated from eachother by 2 sets of buffers, which might interfere with a lot expansion cards.
Plus, every card that has a simular function to something intergrated into the main unit won't work. i've tried CGA and EGA cards, don't work.
This is also the reason i went for a single connector on the current prototype, as the ISA to USB boards became the main focus for my personal usecase.

offcourse someone could modify the PC7000/PC7100 Bios, but i can barely do something usefull in basic

I am interested in your card. I'm even more interested in the older one, the one with three ISA slots. Ik hoor het wel :)
That version has a little flaw in the interface connector to the PC, the top and bottom row of pins need to be swapped to function. an oopsie i missed. that part of the board was designed before i got my hands on a real CE-700E and the interface board is mounted backwards into the case (components to the rear). It's a simple thing to fix in the design. although i cut the interface cable i made in half and crossed every pair of wires to test the board.
 

Ruud

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Where did you find this manual? The only one I found so far is the "Diagnostic manual". But as it does not contain the page shown above, the one you have must be a different one. Could you share it with us, please?

I read point 2 as it accepts cards with memory, which IMHO can be either RAM or ROM, but the Sharp doesn't support DMA to this range. Therefore my request still stands: insert a card with an onboard ROM and try to read that ROM. The EGA card should do fine, just use DEBUG with M C000:0000 (anybody correct me if I'm wrong).

> the top and bottom row of pins need to be swapped to function.
IMHO things would have worked as well if you had put the connector at the bottom of the board

2 4 6 8 ....
1 3 5 7 ....

becomes

1 3 5 7 ....
2 4 6 8 ....

Again, anybody correct me if I'm wrong. And even when I'm wrong, I'm still interested.

> off course someone could modify the PC7000/PC7100 Bios, but i can barely do something usefull in basic
I'm busy with a renovation in the house right now but this is something that could be done during breaks. But I first have to dig up my own Sharp. Or has someone a dump of the BIOS at hand?
 

BlaBla1985

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Where did you find this manual? The only one I found so far is the "Diagnostic manual". But as it does not contain the page shown above, the one you have must be a different one. Could you share it with us, please?
At some point these manuals were freely available from a website called NoDevice, but that is no longer the case, i downloaded several Sharp manuals back then.

IMHO things would have worked as well if you had put the connector at the bottom of the board

2 4 6 8 ....
1 3 5 7 ....

becomes

1 3 5 7 ....
2 4 6 8 ....
... I think you're right, that would work. Would've been an easier fix then the weird interface cable i ended up with to test that first board.


I will have to dig out my EGA card, it's "somewhere" in my computerroom. I have very little experience with debug, but i will give it a try.

I'm busy with a renovation in the house right now but this is something that could be done during breaks. But I first have to dig up my own Sharp. Or has someone a dump of the BIOS at hand?
I have a dump of the PC7100 roms, including the roms from the 20mb hardcard that is no longer working. in the attached zipfile is also the manual for the expansion chassis. It has a lot of hardware info in there, theory of opperation, signal timings. And offcourse the schematic (although there are 2 labels in the schematics that are wrong)
 

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BlaBla1985

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I read point 2 as it accepts cards with memory, which IMHO can be either RAM or ROM, but the Sharp doesn't support DMA to this range. Therefore my request still stands: insert a card with an onboard ROM and try to read that ROM. The EGA card should do fine, just use DEBUG with M C000:0000 (anybody correct me if I'm wrong).
I put my EGA card in the real CE-700E and started everything up, connected a monitor through one of those converters to VGA and got nothing. And with chassis open i realized that it's not an inability of the machine to read ROMs, as the MFM controller card has a ROM on it (right?). The reason it's not working is because the EGA card has a CRT controller in it, and because there allready is a special card that the bios of the computer looks for it simply ignores the EGA bios. I have the CGA card for the PC7000 (which sadly is different then the card for the PC7100) and it just works when connected the same way.
I also couldn't find a combination of working Sharp PC7xxx machine and a dos installatio with debug.

Same goes for XT-IDE, from the service manual:
screenshot1.jpg
That INT13h and 80h, although i have no real idea what that exactly means, i noticed these 2 terms beeing discussed in the ISA to USB thread where they are making the cards bootable.
So, it's not that the computer can't see the ROM, it just ignores it because it's not the ROM from the Plus HardCard (the internal harddrive for the PC7100), or the ROM from the MFM controller (inside the CE-700E).
(I don't know if the XT-IDE uses any DMA).

The reason those USB cards work is that it relies on a driver, not a bootrom. same goes for those external flashcard readers.
 

BlaBla1985

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I've been working on a simple case for the boards, it's a little messy now with wires going everywhere. But it now works in a simular way as the real CE-700E.
CE700minE-Case-open2.JPG

It is powered by a 12V external powerbrick that feeds an ATX PicoPSU. The PicoPSU is turned on and off by a relai that is controlled by a control line from the PC7000/PC7100's PSU. The real CE-700E uses a simular setup, with a relai in the PSU turning the unit on and off when the main PC is switched on. Since the PicoPSU has no -5V line on the connector, i've included a negative voltage regulator so the -12V it turned into -5V.
CE700minE-Case-psu.JPG

When it's closed up, it looks a little like an Apple ][ addon.
CE700minE-Case-closed2.JPG

All in all, the CE-700minE is at least a lot smaller then the actual CE-700E.
Size-difference.JPG
 
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