Okay, the common problem with PC1211 seems to be a damaged LCD screen. I also have a PC1211 with a damaged LCD screen. After watching this video, I plan to try how to fix it.Thank you, Dad.
Hey Birt, I just replaced the LCD in my PC-1211 based on this video, and have to say thank you, thank you, thank you! I just used a heat gun to free the old LCD, and it worked perfectly - it even left the old glue in place so the new LCD is sitting snugly in place, and working perfectly. I also fixed my EL-5100 the same way. I can't tell you how much I appreciate your videos - they have inspired me to start collecting the calculators and computers of my youth :-)
I always wondered if this could be done, and here's a video from Jeff proving it. Thank you so much for another video mate !. It is a pleasure watching your work with a mug of coffee in my hand :-)
That's a blast from the past. I had (still got somewhere) the Sharp PC-1211 with the cassette interface. I used to take it to school back in the day and wander around with it, playing a 3D maze game much like kid do today with their phones. Shame the interface cover is missing from the bottom of the dock.
46:35 What's that button and spring for anyway? The service manual refers to it as an "earth knob"... 🤔 I have a CE-122 with major corrosion that couldn't be saved anymore, despite major cleanup. Too far gone.
I suspect it was an attempt to bleed off any static charge from the printer. Early on there was a problem with the PC-1211 acting screwy while docked and printing. They started sending out two special case screws for the PC-1211 that had springs on the end. The springs would touch the front cover, so the front/rear covers were at the same potential.
@@HeyBirt Thanks for the info! Yeah, I found a note about the replacement screws along with the original (flat blade) crews in the carrying case. I still don't understand why it was so popular to equip these peripherals with built-in batteries. Individual cells were available off-the-shelf in electronics shops.
@@NuGanjaTron well, the original mercury batteries had 300 hours life -and this was the very first "pocket computer" long before anything like a "laptop" existed. Neither Sharp, Casio nor Tandy knew how much users would appreciate battery life vs replace-ability. They learned quickly enough for models 2 and 3, it's less surprising that the first model had flaws. They emphasized "programability" in BASIC differentiating it from mere "calculators". It still was ideal only for accountant and engineer-type applications. It also wasn't long before Model 100 TSR-80, came out so journalists could type out full text (files), and TI and HP came out with "Scientific" calculators for solving math problems without necessarily programming it in Basic. Also "Pocket Computers" were still updated for the Japanese market long after TRS-80 "PC" lineup ended.
So, I have the exact same items as you do Birt... I need to get the LCD display and replace. Spent the afternoon re-furb'ing the printer. Build up a battery pack, like yours. Spent a lot of time getting the printer mechanism freed up. The grease was solid and nothing moved. Once I cleaned this all up and lubricated everything, the printer mechanism now will feed the paper, move the head etc. when the feed button is pressed. However, I have yet been able to get the pocket PC to print. Initiating a LIST with a simple program in the PocketPC seems like it is sending but no activity on the printer. Any ideas? Wish we had the service manual for this thing... I'll start scoping various pins on the connector to see if there is any activity
One difference I see between your printer and mine, when you turn on your printer, yours feeds the paper. Mine does nothing. Not sure if that is relevant or not.
@@andrewkissel3807 Since yours is not triggering the printer init it means that the printer is just dead or perhaps it is not seeing the docking signal from the PC-1211 (forget the proper name but when you plug PC-1211 into printer it completes a circuit so printer knows it is there.)
@@HeyBirt Been looking at this for a couple of days now. I see CPU activity on the address lines, but nothing on the data, R/W, or Chip Enables. It seems like the code is executing in a loop, which makes sense if executing internal code in a polling loop. The schematic/PCB layout for the CE122 I have doesn't exactly match my unit so it had me down a couple of rabbit holes that were not related. I agree, there is something wrong. Wondering if the ROM code in the CPU degraded? The one rabbit hole I went down was trying to determine why the print mechanism/PCU wasn't being triggered to PageFeed at startup. The CE122 schematic shows control of the PF input to the PCU via several diodes + NPN that would assert the PF signal by the main CPU. Only, my PCB is different enough that the one diode that would perform this isn't installed on my PCB. What I need is a working unit to characterize the startup and running state for some of these signals....
Hey Birt, I'm in the middle of refurbishing my PC1 and soon to arrive the PC1 cassette/printer. I have ordered the LCD and the NiMH batteries as per your design. I'm curious what plug pack would work best for the cassette/printer and is it center negative. Thank you for your great content.
Update - replaced the LCD with no issues - Great! But my last 2 EBAY printer purchases proved to be a waste of hard earned money. Both units were corroded so much that the copper trackes and component leads were none existent. I'll still be searching......
Hi, I have sharp ce-122 (same as your printer /casette interface, but not branded as radio shack) and my unit was more corrorroded and the red wire from battery to the smaller pcb with the bus connector fell off because of corrosion, and I don't know where it should be connectoed on the smaller pcb and I was wondering if you could help me by checking where it connects?
I did not take a picture of that board when disassembled. Page 24 of the CE-122 service manual shows where each signal is connected to that PCB. If that does not help look at the contact information for this channel and send me an email so I can email you a picture.,
You will need to add a silicon diode in series with the positive battery lead. This will drop about 0.6V which will let you use alkaline cells. The paper roll is 45mm wide x 25mm OD according to the manual.
I did the same refurbishments as you did here. My printer interface was more corroded because of the batteries, but I managed to clean it up and repair broken traces. Now the printer and saving to cassette works, but I have the same problem as you that I cannot hear any loading sounds back. I managed to get it to load once or twice with the volume from PC sound card maxed out, but still, then it is not reliable. Maybe the cap from the input jack needs replacing? Do you have any suggestions? I doubt it really needs such high volume to load.
The audio output on the cassette interface is very, very low. It is just how they are designed. You need a pre-amplifier to raise it up to a level recordable by a PC sound card.
@@HeyBirt No no, I mean the output to pc works great, I can save my program from Sharp to PC, but I cannot load them back on the Sharp. The signal seems to low to load properly. I wonder if there is a fault or this is by design to expect a higher amplitude.
@@SilverGreen93 The problem is the output level of the cassette interface is too low. On the PC you have recorded a very quiet sound. When you play it back the PC cannot make it loud enough for the cassette interface to hear. Sometimes with Audacity you can normalize the recorded waveform and resave it to get it to work. This makes it as loud as possible in effect. This sometimes does not work though as the original signal is too low. The signal from the cassette interface you want to record need a preamplifier.
Great Video! My display is in great shape but when remove the back cover and insert new batteries, the computer gives a steady beeeeep and the display shows some gibberish. If I push the reset button, the beep starts again and the screen shows different gibberish. Any ideas? Thanks
Hi. I just changed the screen with a new screen, but now when I press ON to start the PC, DEF and RUN show up on the screen and then if powers off. The same happens if I press the reset latch on the back. DEF and RUN briefly show up, and then it shuts off. Do you have any idea what could have gone wrong? The PC was working perfectly before. Thanks!
@@HeyBirt I managed to fix it! 🕵 There was a tiny bit of loose solder that shorted two of the CPU 1 pins that caused the issue! Thank God nothing was burnt! 🙄
Hi Jeff, You can't use a line in port on your sound card, you need to use the microphone input. Use Audacity to bump up the volume of the recording and you are fine. Don't export the file as MP3, use plain WAV. Marcus
Hi, you are correct it 'should' have worked better. I was using the microphone input on a StarTech icusbaudio2d which is what I use for doing voice overs (so I had it plugged in at the time). I did have the microphone volume in audacity turned up as well and it is turned up to 100% in the windows configuration dialog too. I did not try and microphone input on my SoundBlaster card. I'm finishing refurbing a few small tape decks now so I can test saving/loading to them and I'll try the SoundBlaster mic input. Edit #1: I just tried with same USB input and normalized it after recording which brought the level up. I need to find an extension lead to plug into the sound blaster in the back of PC as I don't have the front panel sockets connected. I'll edit this reply again when I try the Sound Blaster.
It would have been NICE if he had even MENTIONED the word "cassette" since everyone else in the world selling one of these has no idea what it's there for...
Okay, the common problem with PC1211 seems to be a damaged LCD screen. I also have a PC1211 with a damaged LCD screen. After watching this video, I plan to try how to fix it.Thank you, Dad.
Hey Birt, I just replaced the LCD in my PC-1211 based on this video, and have to say thank you, thank you, thank you! I just used a heat gun to free the old LCD, and it worked perfectly - it even left the old glue in place so the new LCD is sitting snugly in place, and working perfectly. I also fixed my EL-5100 the same way. I can't tell you how much I appreciate your videos - they have inspired me to start collecting the calculators and computers of my youth :-)
I always wondered if this could be done, and here's a video from Jeff proving it. Thank you so much for another video mate !. It is a pleasure watching your work with a mug of coffee in my hand :-)
That's a blast from the past. I had (still got somewhere) the Sharp PC-1211 with the cassette interface. I used to take it to school back in the day and wander around with it, playing a 3D maze game much like kid do today with their phones. Shame the interface cover is missing from the bottom of the dock.
I have designed a 3D printable cover for the Casio pocket computers so a printable Sharp version should be doable.
46:35 What's that button and spring for anyway? The service manual refers to it as an "earth knob"... 🤔
I have a CE-122 with major corrosion that couldn't be saved anymore, despite major cleanup. Too far gone.
I suspect it was an attempt to bleed off any static charge from the printer. Early on there was a problem with the PC-1211 acting screwy while docked and printing. They started sending out two special case screws for the PC-1211 that had springs on the end. The springs would touch the front cover, so the front/rear covers were at the same potential.
@@HeyBirt Thanks for the info! Yeah, I found a note about the replacement screws along with the original (flat blade) crews in the carrying case.
I still don't understand why it was so popular to equip these peripherals with built-in batteries. Individual cells were available off-the-shelf in electronics shops.
@@NuGanjaTron well, the original mercury batteries had 300 hours life -and this was the very first "pocket computer" long before anything like a "laptop" existed. Neither Sharp, Casio nor Tandy knew how much users would appreciate battery life vs replace-ability. They learned quickly enough for models 2 and 3, it's less surprising that the first model had flaws. They emphasized "programability" in BASIC differentiating it from mere "calculators". It still was ideal only for accountant and engineer-type applications. It also wasn't long before Model 100 TSR-80, came out so journalists could type out full text (files), and TI and HP came out with "Scientific" calculators for solving math problems without necessarily programming it in Basic. Also "Pocket Computers" were still updated for the Japanese market long after TRS-80 "PC" lineup ended.
good stuff! I wish the tandy 102 had a docking station and printer
So, I have the exact same items as you do Birt... I need to get the LCD display and replace. Spent the afternoon re-furb'ing the printer. Build up a battery pack, like yours. Spent a lot of time getting the printer mechanism freed up. The grease was solid and nothing moved. Once I cleaned this all up and lubricated everything, the printer mechanism now will feed the paper, move the head etc. when the feed button is pressed. However, I have yet been able to get the pocket PC to print. Initiating a LIST with a simple program in the PocketPC seems like it is sending but no activity on the printer. Any ideas? Wish we had the service manual for this thing... I'll start scoping various pins on the connector to see if there is any activity
One difference I see between your printer and mine, when you turn on your printer, yours feeds the paper. Mine does nothing. Not sure if that is relevant or not.
CE-122 service manual found!!!! Woot.. Now to debug.
@@andrewkissel3807 Since yours is not triggering the printer init it means that the printer is just dead or perhaps it is not seeing the docking signal from the PC-1211 (forget the proper name but when you plug PC-1211 into printer it completes a circuit so printer knows it is there.)
@@HeyBirt Been looking at this for a couple of days now. I see CPU activity on the address lines, but nothing on the data, R/W, or Chip Enables. It seems like the code is executing in a loop, which makes sense if executing internal code in a polling loop. The schematic/PCB layout for the CE122 I have doesn't exactly match my unit so it had me down a couple of rabbit holes that were not related. I agree, there is something wrong. Wondering if the ROM code in the CPU degraded? The one rabbit hole I went down was trying to determine why the print mechanism/PCU wasn't being triggered to PageFeed at startup. The CE122 schematic shows control of the PF input to the PCU via several diodes + NPN that would assert the PF signal by the main CPU. Only, my PCB is different enough that the one diode that would perform this isn't installed on my PCB. What I need is a working unit to characterize the startup and running state for some of these signals....
Hey Birt, I'm in the middle of refurbishing my PC1 and soon to arrive the PC1 cassette/printer. I have ordered the LCD and the NiMH batteries as per your design. I'm curious what plug pack would work best for the cassette/printer and is it center negative. Thank you for your great content.
Update - replaced the LCD with no issues - Great! But my last 2 EBAY printer purchases proved to be a waste of hard earned money. Both units were corroded so much that the copper trackes and component leads were none existent. I'll still be searching......
Does anyone know of a source for the plastic front screen protector component that sits in front of the LCD and bezel? Mine has a crack in it.
Hi, I have sharp ce-122 (same as your printer /casette interface, but not branded as radio shack) and my unit was more corrorroded and the red wire from battery to the smaller pcb with the bus connector fell off because of corrosion, and I don't know where it should be connectoed on the smaller pcb and I was wondering if you could help me by checking where it connects?
I did not take a picture of that board when disassembled. Page 24 of the CE-122 service manual shows where each signal is connected to that PCB. If that does not help look at the contact information for this channel and send me an email so I can email you a picture.,
@@HeyBirt Thanks, found where it should connect
Do you have the power supply polarity for the CE-122 (the same that the TRS 80 Printer cassette Interface, but from Sharp) ?
It is a Sharp EA11E power adapter, 6VDC unregulated, center negative.
@@HeyBirt thanks. Pretty sur i have one but unable to find it. Damned power plug everywhere
Is it fine to power from SR44 considering they have 1.55V?
Also, what paper width does this take?
You will need to add a silicon diode in series with the positive battery lead. This will drop about 0.6V which will let you use alkaline cells.
The paper roll is 45mm wide x 25mm OD according to the manual.
Thanks, I will try that
I did the same refurbishments as you did here. My printer interface was more corroded because of the batteries, but I managed to clean it up and repair broken traces. Now the printer and saving to cassette works, but I have the same problem as you that I cannot hear any loading sounds back. I managed to get it to load once or twice with the volume from PC sound card maxed out, but still, then it is not reliable. Maybe the cap from the input jack needs replacing? Do you have any suggestions? I doubt it really needs such high volume to load.
The audio output on the cassette interface is very, very low. It is just how they are designed. You need a pre-amplifier to raise it up to a level recordable by a PC sound card.
@@HeyBirt No no, I mean the output to pc works great, I can save my program from Sharp to PC, but I cannot load them back on the Sharp. The signal seems to low to load properly. I wonder if there is a fault or this is by design to expect a higher amplitude.
@@SilverGreen93 The problem is the output level of the cassette interface is too low. On the PC you have recorded a very quiet sound. When you play it back the PC cannot make it loud enough for the cassette interface to hear.
Sometimes with Audacity you can normalize the recorded waveform and resave it to get it to work. This makes it as loud as possible in effect. This sometimes does not work though as the original signal is too low.
The signal from the cassette interface you want to record need a preamplifier.
Great Video! My display is in great shape but when remove the back cover and insert new batteries, the computer gives a steady beeeeep and the display shows some gibberish. If I push the reset button, the beep starts again and the screen shows different gibberish. Any ideas? Thanks
This is a state I have seen them get into and have not found a solution. It would not hurt to try a fresh set of batteries and hope that solves it.
Tried new batteries and the problem remains.@@HeyBirt
Hi. I just changed the screen with a new screen, but now when I press ON to start the PC, DEF and RUN show up on the screen and then if powers off. The same happens if I press the reset latch on the back. DEF and RUN briefly show up, and then it shuts off. Do you have any idea what could have gone wrong? The PC was working perfectly before. Thanks!
Check around the areas of the PCB where the metal tabs of the LCD frame are. It is very easy to scratch a trace and cause a problem.
@@HeyBirt I managed to fix it! 🕵 There was a tiny bit of loose solder that shorted two of the CPU 1 pins that caused the issue! Thank God nothing was burnt! 🙄
@@SilverGreen93 Great news!
Hi Jeff, You can't use a line in port on your sound card, you need to use the microphone input. Use Audacity to bump up the volume of the recording and you are fine. Don't export the file as MP3, use plain WAV.
Marcus
Hi, you are correct it 'should' have worked better.
I was using the microphone input on a StarTech icusbaudio2d which is what I use for doing voice overs (so I had it plugged in at the time). I did have the microphone volume in audacity turned up as well and it is turned up to 100% in the windows configuration dialog too.
I did not try and microphone input on my SoundBlaster card. I'm finishing refurbing a few small tape decks now so I can test saving/loading to them and I'll try the SoundBlaster mic input.
Edit #1: I just tried with same USB input and normalized it after recording which brought the level up. I need to find an extension lead to plug into the sound blaster in the back of PC as I don't have the front panel sockets connected. I'll edit this reply again when I try the Sound Blaster.
Great video.
It would have been NICE if he had even MENTIONED the word "cassette" since everyone else in the world selling one of these has no idea what it's there for...
What are you referring to?