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Many versions of PC-1500 ? PC-1600 too !

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Hey, we focused on the PC-1500 and PC-2 versions but do you know the PC-1600 versions ?
As this pocket is compatible with PC-1500 we can talk about it.

I have two PC-1600 but they are not exactly same.
Lets see the old version :
PC-1600 V1

and the new one :
PC-1600 V2

The memory place is different, as small board for the V1 and on CPU board for the V2.
If you look at the Technical Reference Manual you will have the first version :
PC-1600SCH V1

And if you look at the Service Manual there is the V2 :
PC-1600SCH V2

Are you looking for a screwdriver to open your precious PC-1600 ? 😉

Tandy a full system closed to Sharp one.

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Most of you better know the Sharp system. Why ?
Maybe because Tandy/Radio shack didn’t follow Sharp along the years for this pocket computer.
Here is the Tandy system :
EMI_2609

We know some PC-3, PC-4… but the PC-2 is still at the PC-1500 step.
I don’t know exactly why…
Someone can help me with this item ?

I already presented the PC-2.
To be precise I presented one version of the machine.
Yes, you really read “one version”, maybe the third one.
On the picture you can see lot of blue straps and a IC named “SC613128” with “A03”.
TRS-80_PC2_004

We know it’s the firmware revision. Then A03 seems to be the third.
Does someone have the first and the second ? Uh… that sounds mysterious…

I have the fourth !
Tandy_PC2_A04

As you see, no blue straps on the CPU board.
In fact it’s exactly closed to the PC-1500 evolution.
But… one moment please…
With some friends we had a really interesting discuss about Tandy and Sharp.
Like the chicken and the egg … which came first?

After reading this first article you have more questions than answers, isn’t it ?
– who have the versions one and two ???
– who can answer the chicken/egg question ???

Donation ?

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Hello dear visitors,

My site tries to gather all the information on the fantastic machine that was the handheld Sharp PC-1500 and its various versions.

To advance this work I need your help.
I’m not talking about donations “money” but documentation, books, hardware, software, plug-ins, accessories Sharp, Tandy … etc to complement this collection and also serve me for trade.

For example, Tandy sold a lot of software for the TRS-80 PC2 (Radioshack Tandy) but I found only rarely.
Besides my Tandy PC2 is not the best form and if someone has one to offer I agree 🙂

There is also the original boxes that I miss. Perhaps you have in your attic?
User manuals?
…

As you understand, anything can interest me and use me to advance this site.

I listen to your suggestions 🙂

Thank you to you.

ROM1500.

PC-1560 : CE-161 to replace system ROM ?

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Working on the PC-1560 project need some tools.
We have to design a new system ROM but at this time don’t have to work with (E)EPROM programmers.
The best way is to look at our hardware stuff !

We most have CE-161, isn’t it ?
Ok, how does this memory module work ?
It need to be plugged on the 40 pins bus.
The PC-1500(A) schematics shows that we have these signals available on the connector:
– /Y0
– /Inhibit (active low to disable the system ROM)

CE-161 schematics shows a 40H138 (Demux) selected by /Y0 (active low) going to /G2A (active low). This signal is nothing but &0000H address.

The system ROM is at &E000H… /Y3 from the 40H139 in the PC-1500.
Simple, no ?

Ok, a DOUBLE hardware inverter is all we need.
The inverter will a the same time :
– connect 40H139 signal /Y0 or /Y3 to the CE-161 on /G2A
– connect /Inhibit to GND or let it to it’s high value.

The inverter must be inside the PC-1500.
Cut the strap from pin 4 of the 40H139.
Connect this pin to one side of the inverter.
Connect pin 7 to inverter’s other side.
Connecter inverter middle pin to the cutter strap.
Now you can choose CE-161 function : RAM or system ROM.
… don’t miss the /INHIBIT pin…

I will soon show your a picture of the system.

Here is the updated schematics.
CE-161_ROM

CE-163 owners will have a dual ROM system… but be careful to switch ROM when powered off.

PTA-4000+16

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It’s another under license production by Hiradas Technika.
Do you use the module port to expand memory ? Yes ! 16KB more with CE-161
But they don’t !
Their PTA-4000+16 is nothing but a PC-1500 with a self made 16KB memory board inside.
Crazy, no ?
Stupid ! The module port has being removed and it’s door is glued.

PTA-4000-16_018 PTA-4000-16_019
PTA-4000-16_003 PTA-4000-16_005

Look at the buzzer… it’s now on the CPU side.
PTA-4000-16_009 PTA-4000-16_012

PTA-4000-16_016