A Televideo TS803 might live again Part 1
Posted: Mon Nov 21, 2022 7:22 pmAfter limited success on my other systems revival attempts so far, I decided to unpack and try another one.
These have all traveled from Auckland to Kaiapoi, and haven't been powered on in at least 20 years.
This one is a Televideo TS803 Z80 CPM System with twin 5.25 floppy and integrated monitor from the 1980's.
download/file.php?mode=view&id=677
I'll upload a real photo when it isn't in pieces.
Finding the keyboard was the hard part, as it wasn't in the box with the system and there are about 50 boxes of "stuff" piled up.
Having finally located the keyboard, and once it was all assembled, I was ready sty start.
First it was opened up, cleaned and given a thorough visual inspection.
Then the moment of truth, so I crossed a few fingers and powered it on.
No smoke, so that was a good start, but one floppy drive was bouncing off the end stop, so I powered it off to remove the power to that fdrive.
Tried again, and noticed some led activity, so that looked promising, but nothing showed on the screen.
Time to read the manual. The leds are four that provide a diagnostic pattern, and it indicated a memory issue.
Of course, it was soldered in, so a bit harder to test.
No bother, I have a desoldering station, and a few hours later the eight MK4564's were out and sockets installed and a basic continuity test done to verify things looked reasonable.
Now the memory.
I'm a bit of an Arduino fan, so a bit of searching and building eventually resulted in an Arduino 2164 memory tester.
The MK4564 is an equivalent to the 2164.
I ran all of them through the tester and none failed.
Time to rummage through the bits box.
This produced plenty of 2164's and even another full set of MK4564's.
Before reassembling the logic board, I have removed the CRT PCB and will see if anything looks amiss before trying it again.
more to follow...
Mark.
These have all traveled from Auckland to Kaiapoi, and haven't been powered on in at least 20 years.
This one is a Televideo TS803 Z80 CPM System with twin 5.25 floppy and integrated monitor from the 1980's.
download/file.php?mode=view&id=677
I'll upload a real photo when it isn't in pieces.
Finding the keyboard was the hard part, as it wasn't in the box with the system and there are about 50 boxes of "stuff" piled up.
Having finally located the keyboard, and once it was all assembled, I was ready sty start.
First it was opened up, cleaned and given a thorough visual inspection.
Then the moment of truth, so I crossed a few fingers and powered it on.
No smoke, so that was a good start, but one floppy drive was bouncing off the end stop, so I powered it off to remove the power to that fdrive.
Tried again, and noticed some led activity, so that looked promising, but nothing showed on the screen.
Time to read the manual. The leds are four that provide a diagnostic pattern, and it indicated a memory issue.
Of course, it was soldered in, so a bit harder to test.
No bother, I have a desoldering station, and a few hours later the eight MK4564's were out and sockets installed and a basic continuity test done to verify things looked reasonable.
Now the memory.
I'm a bit of an Arduino fan, so a bit of searching and building eventually resulted in an Arduino 2164 memory tester.
The MK4564 is an equivalent to the 2164.
I ran all of them through the tester and none failed.
Time to rummage through the bits box.
This produced plenty of 2164's and even another full set of MK4564's.
Before reassembling the logic board, I have removed the CRT PCB and will see if anything looks amiss before trying it again.
more to follow...
Mark.