Category Archives: Blog

TE-1508 : Internal 512KB RAMDisk !

Ok, my tests are OK on the prototype board.

TE-1508_RAMDisk

Here are the module features :
– Reference TE-1508
– 512KB of static RAM
– 16 pages of 32KB located in the ME1 zone
– Software selection of the page
– Software Activation/Desactivation (for example the IWS video interface uses same zone in ME1)
– Optional CR-2032 backup battery
– Optional write protection by jumper.

The page selection uses a very special feature of the LH5801 processor which was never being used before… because Sharp never routed this pin !
The data bus can work as a multiplexed bus like the Intel 8052 from the MCS51 family. It means that at one time data are on the bus and another time it’s something else. And this is f… good feature ! I don’t have to use many logical cells. Page 42 of the Technical Reference Manual describe it as the ATP instruction. It pushes the accumulator value on the data bus and provides all signals to store it in a latch. And here we just have to plug an octal latch.

Manual routing is done !
Installing it in your Sharp PC-1500(A) will need some wrapping wires…
TE-1508_Reduce

I need some tests with the final board and i will tell you the price…

Is it enough to store your programs ? 😀

TEAM1560 : Testing a new module… TE-1508

I’m testing a new hardware to take place inside the PC-1500(A).
The schematics is OK, the circuit board is manually routed.
And i’m testing it with some classic DIP components.

This new module will be the TE-1508, a 512KB RAMDrive.
It’s like 25x the maximum user RAM area.
All this memory is organized in 16x32KB pages with a write protect jumper and a CR2032 battery.
It’s in the first half of the ME1 zone and can be disabled by software. (Remember that the IWS video interface uses the same ME1 zone.)
But installing it inside the PC-1500 will be a big job.

Stay tuned…

TEAM1560 : TE-1507 memory module designed to extend Basic

The TE-1506 could be too much complicated for most of the users.
Those who don’t need to replace system ROM but want a permanent Basic extension will be interested by this new module !
It’s like a CE-161 but with 2x16KB RAM and 2x16KB EEPROM for Basic extension.

Here is the schematics :
TE-1507

If a least 10 or more readers are interested i can produce it as a kit or mounted.
But only after having released the TE-1506 module.
If you have suggestions or see an error then please contact me.

Pocket Computer Newsletter : Part I, issues 13 to 28

That’s crazy, i can’t find the “Pocket Computer Newsletter” magazines anywhere !
But i have some articles about the PC-1500 extracted from it.

Here is the first part with issues 13 to 28.
You’ll find issue number at the bottom of each page.

Couvertures_Page_1Download

If you own the original magazines, please, contact me.
Maybe would you accept to offer it, sell it or send high quality scans…

Sharp CE-150 : pinions replacement solution ?

Hi all,

We all have ALPS printer modules with broken pinions.
Who knows a replacement part ?
EMI_2440

As told by Paul in the forum :

“The pinions measure 3.75mm OD and have 13 teeth. The shaft measures 1.55mm. I’m thinking that this is very similar to some remote control helicopter pinions I found online – 13T 1.5mm shaft mod .25 (101P). I’m going to check with a local RC hobby shop to see if they have anything, but otherwise I’ll try to order some of these pinions (http://www.xtreme-production.com/xtreme … ts_id=3013).”

Someone used pinions from a Sony CD player.

If you want to share your solution, please, contact me.

Team1560 : Prototype board for TE-1506 memory module ordered

The TE-1506 memory module is an important step on the way to the PC-1560.
It’s Sharp PC-1500(A) compatible and offers some nice features that missed from a long time.
I have ordered the prototype board and will receive it in two weeks.

CE-1506

In the size of a module you’ll have a 32KB static RAM and a 32KB Xicor EEPROM.

First remember the memory map. Example for the PC-1500A :
TRM 173

Now let’s see how it works :
The RAM :
It’s divided in two 16KB memory spaces from &0000H to &3FFFH and will replace your CE-161 module.
The LH5801 provide 2 flip-flops named PU and PV. They are mainly used to switch extension’s ROMs located from &8000H to &BFFFH.
Here you will be able to configure by jumper if pages are selected by PU or PV.
Natively the Basic can’t switch the RAM pages but… we will teach him.
For information the TRAMSoft memory extension use same page selection.
The whole RAM (from &0000H to &3FFFH) can be write protected by removing a jumper.
TE-1506_RAM

The EEPROM :
Xicor offers us a the perfect solution to store ROM extensions.
First, it’s 5v programable, second, it’s byte erasable !
No need of external EPROM programmer.
CGH already tested the Xicor solution on his PC-1500 as a permanent RAMDisk.
The 32KB of our EEPROM can work in two modes :

1 – As two 16KB ROM extensions located from &8000H to &BFFFH.
Depending on the peripheral used (CE-150 or CE-158) you can select the EEPROM’s position in the memory space.
If you use the CE-150 printer/tape interface then you have to select PU=1
If you use the CE-158 RS-232C/Parallel interface then you have to use PU=0
The two 16KB pages are selected by PV flip-flop.
Do you remember CGH’s tools ? BASWORD will be your friend.
TE-1506_ROM_CE-158TE-1506_ROM_CE-150

2 – As a 16KB ROM extension + 16KB system ROM replacement.
The first 16KB page becomes the new system ROM and the second 16KB page is still a ROM extension located on PV=0 or PV=1 zone.
The whole EEPROM can be write protected by removing a jumper.
TE-1506_SYSROMPV0TE-1506_SYSROMPV1

Amazing, no ? This will offer a solution to create you own root system !
Could you image a Forth native PC-1500 ?
an assembler native PC-1500 ?
a C native PC-1500 ?
Wow…

First tests in 3 weeks !

Tom’s story : my PC-1500 and Marilyn

I like when my readers want to share some of their PC-1500’s stories.
Today thanks to Tom for this one :

Memories about Marilyn
======================

Hi folks,
recently I found a 30+ years old school exercise book that I used as my private listing library for my very first computer which was – you might guess – a SHARP PC-1500.
It’s a lot cool stuff in it (e.g. a kind of minesweeper game that runs on the CE-150 and some projective 3D math), but I found one bonbon I’d like to share here: The first digitized picture I ever “took”.

Monroe

When I saw this, memories sprang into my mind:

I was a school boy, maybe 17, and a fan of Marilyn. And I had this brand new PC-1500/CE-150 which I spend ALL my money for.
So I took a photo of her as a template, painted a free hand silhouette image on an A3 paper and rasterized it utilizing a transparent millimeter paper. After that, my best friend had to dictate me all the ZEROs and ONEs for each pixel, in order to capture a “huge” dataset by hand.
I still remember that it was a completely CRAZY amount of work, but the result was very nice for the time of the early 80s.
In fact the jaws of my buddies dropped, when they saw the CE-150 at work, producing that image – point by point.
Well, today we take a 24M picture by the press of our fingertip …
But that doesn’t beat old memories, right? 🙂

Thanx to Eric for this great website!
Cheers
Tom

I will soon tell you another “Tom’s story”… let’s find the memory…