PC-1500 28Kb – Part 1

Lukas told me about his gift that there will be a 28Kb PC-1500.
This was a good news !
But this is more than a good news.
Lets me present this updated machine.

Opening the CE-150 box shows us some nice things.
Do you see what i mean ? Examine this picture carefully…

First there is a sticker “28K”. This means that the memory size is 28Kb. It’s the maximum reachable on this pocket because of the display addressing method.
Let’s open the machine…

Here is it :
This extension it made of 13 x 6116 ICs and present a total amount of 26KB of memory.
It’s a very professional board. You can see where the RAM pins are placed ? Simply on the holes between sides. Well done guys !
This board is named “DF1SE PC 1503”. (If you know more about it then use the contact form to tell it to me.)
PC-1500_28Kb_011 PC-1500_28Kb_012

Second, there is a switch on the PC-1500 side :

Do you know why ?
The LH5801 microprocessor is driven by a 2,6Mhz oscillator.
In 1982 it was fast ! In 1984 it was slow ! lol
This button switch between the 2,6Mhz and a new 5Mhz oscillator. Yes, the twice !!!
Uh… this has some back effects to the real time clock… but the speed is here !

The printer case and the pocket pouch have being modified for the switch.
PC-1500_28Kb_003 PC-1500_28Kb_006

Third, there is a very nice update of the printer’s door.
A little black plastic strap help the opening.

Next time i will explain something very particular on this PC-1500.
Do you have an idea ???

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