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.