+- Discussion Forum for all things Microbee (https://microbeetechnology.com.au/forum)
+-- Forum: Microbee Forum (https://microbeetechnology.com.au/forum/forum-1.html)
+--- Forum: Non-Microbee Vintage discussion (https://microbeetechnology.com.au/forum/forum-8.html)
+--- Thread: Dick Smith System 80 (/thread-141.html)
Dick Smith System 80 - ChickenMan - 09-05-2020
I recently acquired a Dick Smith System 80, a TRS-80 Model 1 clone made by EACA in Hong Kong. It came with a lower case module and an X-4020 expansion unit that gives me a whopping 48kb memory and a floppy disk controller.
Reading the manuals, I was able to use the standard Microbee grey cable with DIN plug to connect the composite video output to monitor. After a bit of volume adjusting, I was able to load in a TRS-80 tape with the on-board Cassette deck, so all working as expected so far, but load time is quite long and I got no sound from the games via the Cassette port at the back.
I could have connected up a 5.25" floppy to the X-4020 expansion unit but why not use a Gotek instead. Some floppy images were gathered from Tezzas site ( https://classic-computers.org.nz/ ), used HxCFloppy Emulator software to convert the DMK files to Gotek HFE format and was now able to boot disks and play some games. Woo hoo...
This is a middle model System 80, just before the Blue Label version, that has no speaker in it so after a lot of reading I was able to direct the Cassette 1 recording pin to the external Cassette 2 port with a wire, made up a DIN plug and attached some powered speakers. Fantastic, now have sound from all the games
So have now made up some disk images with a heap of games on them as well as 20+ Infocom Adventure games. All booting the NEWDOS/80 system. It can even boot CP/M ver 1.4. Only thing thats needed is to install an audio amp internally with Volume control. This will be done as soon as some bits arrive.
Now time to start playing some of those great TRS-80 games, many that have been converted to run on the Microbee, but now on the original hardware.
RE: Dick Smith System 80 - ChickenMan - 01-06-2020
Have finally installed a small 3 watt Audio amp and added a speaker in the spot where its mounted in the Blue Label System 80. Volume control comes out the right hand side (yes I had to drill a 1/4" hole
) and all is working fantastically well. Can now finally put the lid back on
RE: Dick Smith System 80 - CheshireNoir - 16-06-2020
Awesome find and I appreciate the details on what you modded on it. Goteks are such an awesome solution to crumbling media, and getting images off newer systems into older systems.
RE: Dick Smith System 80 - ChickenMan - 17-06-2020
Yes Goteks have been a savior to the vintage computer collector really, I have them on most of my Microbees as well. The FlashFloppy firmware natively supports the DSK image format that the Microbee uses making life so much simpler. For the System-80 disks to boot, they need to be converted to HFE format though, not a big deal really but just another step.
I must take a few close up pics of the small audio amp I installed and where I picked up the connections for it as it might help others.
RE: Dick Smith System 80 - ChickenMan - 22-09-2020
This is my Gotek for the System 80 with LED, Sound and Rotary mods added. I bought a grey Gotek that didnt have a display or the 2 buttons that was extra cheap at the time. So added in the 2 buttons removed from a dead Gotek and decided to add a larger LCD screen which I mounted in the top of the case. Not wanting yet another power pack and leads, I decided to get the 5v needed from the large 5v regulator on the main motherboard of the System 80 and with the top cover on, the wires go out through the large Expansion socket hole. Works well
RE: Dick Smith System 80 - ChickenMan - 22-09-2020
This is the small audio amp I installed on the right hand side of the System 80 to the right of the Cassette player and in front of the power supply where there is a ton of room. I had to drill a small 1/4" hole in the case so the volume control pot can come through.
Since most of the TRS-80 games send the sound out via the external cassette port, unfortunately the System 80 has the main cassette built in, so no sound out the back cassette port 2 without some sort of modification. I made no modification and just picked up the sound signal thats going to the inbuilt cassette unit from Point 1 in the pic. Picked up 5v from Point 2 and earth from Point 3. A 50mm 4ohm speaker is mounted under the Video motherboard in the spot already provided for it. That spot though is designed for a 60mm speaker, so had to put in a holding strap to keep it in place.
The small 3w audio amp (uses PAM8403 chip ) with knob was bought off ebay $9.90, the speaker $10 and some wire so not an expensive upgrade.
RE: Dick Smith System 80 - CheshireNoir - 23-09-2020
Thanks for sharing these mods, ChickenMan!
It's always interesting seeing how other people overcome issues.
RE: Dick Smith System 80 - RP70 - 30-11-2025
(22-09-2020, 07:18 PM)ChickenMan Wrote: This is the small audio amp I installed on the right hand side of the System 80 to the right of the Cassette player and in front of the power supply where there is a ton of room. I had to drill a small 1/4" hole in the case so the volume control pot can come through.
Since most of the TRS-80 games send the sound out via the external cassette port, unfortunately the System 80 has the main cassette built in, so no sound out the back cassette port 2 without some sort of modification. I made no modification and just picked up the sound signal thats going to the inbuilt cassette unit from Point 1 in the pic. Picked up 5v from Point 2 and earth from Point 3. A 50mm 4ohm speaker is mounted under the Video motherboard in the spot already provided for it. That spot though is designed for a 60mm speaker, so had to put in a holding strap to keep it in place.
The small 3w audio amp (uses PAM8403 chip ) with knob was bought off ebay $9.90, the speaker $10 and some wire so not an expensive upgrade.
This is great. I am lucky enough to have acquired a Video Genie here in the UK and really like the machine. I am only (very) amateur at soldering but this looks within my modest skillset. I have all the parts for this but could you help me identify the resistor in the photograph? Would be great to get some sound out of this computer. Thanks.
RE: Dick Smith System 80 - ChickenMan - 01-12-2025
(30-11-2025, 12:10 AM)RP70 Wrote: I have all the parts for this but could you help me identify the resistor in the photograph? Would be great to get some sound out of this computer. Thanks.
That was a small 1k 1/4w resistor but not sure if really needed, I added it in because I had some