TRS-80 Pocket Computer Model PC-2

[jappie]

Hello

I've just got my PC-2 out after 30 years of hiding in a box. I got 4 new batteries in and after power up & NEW0,  I wrote the MEM command....

First number that came up was 24576 which is the number I've always seen because I have the 8K expansion module.

 

Went in PRO mode and started writing lines, but it would not "keep" them....did the "reset" thing, removed the 8K module, NEW0 and MEM and got 16384 which is normal ( 16k ) without module.

Put back the 8K module, power up, went in PRO mode, and then all kind on funny garbage appeared,  lines from ( I guess )  and old program that was half delete ??? hard reset again, NEW0, MEM command and got 10042 ! not good !........... removed the 8K module, got 1850 of memory !!!  where is my 16K  basic MEM gone ???  I used to get 16384 but now 1850 ( without the 8K module ) but at least now, the computer is keeping my program lines in memory. but why 1850 instead of 16384 ? ( 16*1024)

 

Opened up the computer, nothing really strange, looked under a microscope,    I did find a strange looking Gelatine bar with sesame seeds inside !!! some sort of humidity thing ?? about 2 inch long secured in a corner .

 

Hope somebody will remember this old pocket computer.

 

Jean-Pierre

[Turbo-Torch]

You obviously have something going on with the internal RAM.  Is that "gelatin bar" bleeding over the circuit board? 

I have a Sharp PC-1500 version that had funky issues with the display and that bar thing was like a hemorrhaging internal organ.  Nasty, sticky blob that oozes and leaks all over and doesn't want to wash off your hands...took a lot of q-tips and rubbing alcohol to get the circuit board clean.  It also seemed to migrate to certain areas of the board while leaving other areas spotless, as if it was intelligent and knew what it was going after.

After removing it and cleaning everything, the PC has worked perfectly since.

 

 

 

 

[jappie]

yeah, saw your picture before !

I took a picture of the bar after it was removed, before it was a solid bar Kitt-Katt type, all secured in a corner inside the casing, it did not "migrate" anywhere, but as soon as I touched it it crumbled into several pieces. stinks a lot too. I wonder if these seeds aren't mushrooms ?

 

Also removed the batteries from my printer which I had already replaced severals years ago, again they had leak. Found 2 plastic gear broken, each on the motors of the feed and pen holder. Can't see how to replace them.

[Turbo-Torch]

Hahaha...it actually looks like it might taste good!

 

Now I really want to know what its purpose is/was?

 

Not sure what to tell you about the memory issues...are you using 1.5 volt alkaline and not nimh?  If using an external power supply, is the output ok?

[jappie]

I used 1.5v alkaline Duracell with & without power supply, and with & without the printer interface, which I replaced the rechargeable batteries by a adjustable power supply, I think I had 9 v & 1 amp, I could see the printer using approx. 600 milliamp at start-up.

 

JP