Hi, In my PC-1500 i had problems with the first TE-1507 version using Xicor memory.
It was impossible to write something in an unprotected X28HC256.
The Team1560 needs were to have a big system RAM and a place to test system ROM extensions.
Done ! The TE-1507 is now working with 2 RAM ICs and the R/W protection is done by jumper.
Here are some pictures the prototype :
This one, number 3, is reserved for…….. ? Stay tuned 😉
The release version should be available in one month.
The TE-1507 memory module is now in my PC-1500 !
This module offers a very wide memory space for developers.
It was initially planned to have RAM and EEProm but due to a bad EEProm lot… it’s now full RAM.
Standard memory for Basic/ML :
– from &0000 to &3FFF
– 2 x 16KB switchable by PV or PU (jumper to select active signal)
– read only by removing a jumper
– disabled by removing a jumper
EEProm memory (here it’s RAM) for ML only as system/peripheral ROM extension:
– from &8000 to &BFFF
– 2 x 16KB switchable by PU (as in the CE-158 interface)
– set by jumper if it’s in the PV=0 (like CE-150) or PV=1 (like CE-158 or CE-162E) memory space
– read only by removing a jumper
– disabled by removing a jumper
The two memory addresses can be inverted by placing the enable jumpers on the switch positions (90° move)
Here are the pictures :
This module will be a very good investment to expand your PC-1500(A) !
The Team1560 member CGH is working on a ROM builder to add Basic keywords from a wide library. Cool, isn’t it ?
The price for this special module is $75 without shipping costs.
Here is my full SHARP system “in box”.
– PC-1500 small box
– PC-1500 big box with manuals
– PC-1500A big box with manuals
– CE-150 printer and tape interface
– CE-151 4KB memory module
– CE-152 tape recorder
– CE-153 Soft ware board
– CE-154 Briefcase
– CE-155 8KB memory module
– CE-156 Katakana software tape
– CE-157 Katakana ROM module
– CE-158 RS-232C and parallel interface
– CE-159 8KB memory module with write protection
– CE-160 7,8KB Read only memory module
– CE-161 16KB memory module
– CE-162E Tape and parallel interface
The CE-163 2x16KB memory module is missing.
Impossible to find the box. Do you have one ?
The boards and the 74HCxxx components are here.
The memory ICs will arrive soon.
Ok, my tests are OK on the prototype board.
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…
I need some tests with the final board and i will tell you the price…
Is it enough to store your programs ? 😀
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.
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 :
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.
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.
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 :
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.
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.
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.
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 ?
First tests in 3 weeks !
The PC-1500 is a really well designed pocket computer and offers many ways to extend it’s software and hardware capabilities.
Some companies were seduced by the Sharp solution and it’s “owner” memory modules.
EDTech was one of these companies and were offering a solution for education administrators :
(Picture taken from eBay)
Externally it looks like the PC-1500A + CE-150.
But internally there is a custom memory module :
It holds a 57256 32KB EPROM
We have to distinguish three kinds of memory modules :
– RAMs stored between &0000 to &3FFF (like 4KB CE-151, 8KB CE-155, 8KB CE-159, 16KB CE-161 or 2x16KB CE-163)
– ROMs or EProms stored between &8000 to &BFFF (that extends the system with Basic instructions)
– Pseudo ROMs stored between &0000 to &3FFF (like the 7,8KB CE-160 used to store custom invisible Basic programs)
– EProms stored between &0000 to &3FFF used to store invisible Basic programs
The EDTech ROM is in this last case.
But if you understand address decoding “&0000 to &3FFF” is only 16KB wide.
On this module there is a TTL 74LS73 IC. It’s a dual J-K flip-flop with clear.
It’s function is to select one of the two 16KB pages.
Open the Technical Reference Manual and look for memory configuration and /S3 signal.
On the PC-1500 this signal select a memory zone starting at &5800.
On the PC-150A this signal select a memory zone starting at &6800.
Nice, this can work with the two pocket computers.
On my schematics you can see it connected to the CLK pin of the Flip-flop.
Now examine the content of each 16KB page (only the beginning, the rest is the EDTech program)… lines 11, 40 and 41
1st page :
2nd page :
The POKE instruction writes a value to a memory case. By this way the program can swap the page.
Depending on the address it writes a 0 or 1 on the J and K entries and the clock push it to the Q and /Q outputs.
It’s a very nice design, isn’t it ?
I asked EDTech to get some informations and maybe a user manual.
They answered but nobody was able to help me.
Can you ?
Contact me if you have other “non Sharp” modules… 😉