Setup and use a GOTEK with a Tandy Color Computer 

I just wonder... I had 3 double sided drives on my CoCo 3. Originally RS-DOS allowed 35 tracks, it was modified by some CoCo owners to read and write 40 tracks. When 720k drives came out the amount of tracks doubled from 40 to 80, again CoCo owners modified RS-DOS to read and write all 80 tracks. The amount of data on the disk increased when the tracks were doubled, however there were limitations as only track 17 was used for the directory meaning you could still only have 72 files on a disk, for the most part this was not very limiting as most disks were full before you got to that 72 file limit. Later when 1.2 5.25 inch disks and 1.44 3.5 inch disk were introduced, the data rates were doubled as each track had double the data per track. This time some people added a hardware modification to over clock the floppy controller to read and write at the faster data rates. Please note: Not all floppy controller can be modified to read the faster data rates. The CoCo's RS-DOS has a second limitation, it sees only one side of the floppy drive, however it can access both sides again through modifying RS-DOS. After modifying RS-DOS to access both sides, the system still only sees each double sided floppy drive as being 2 separate drives. Drive 0 is the side normally read and written when using a single sided drive and be formatted identically to a single sided floppy, and Drive 1 would be the opposing side of the same disk. Now for the third limitation... CoCo 1, 2, and 3's when having both single and double sided floppy drives can not tell how many track the drive or floppy has. It is up to the user to know this. If you put a 40 track disk into a 80 track drive, RS-DOS can not figure out what is going on. There is a patch for this, but the patch is one that needs to be done after the system is booted and places in ALL RAM mode. All RAM mode copies all RS-DOS, BASIC, EXTENDED basic ROM data to RAM memory then switches the ROM out of the system and uses only RAM or "ALL RAM". This can be done in 64k systems only, as 23k systems did now have memory located in the addresses need to do this. Once in ALL RAM mode a basic program would poke data into the appropriate RAM locations and would make the floppy drives double step. allowing a 40 track drive to be read properly. You could then also switch back to not double stepping by restoring the original data and there by wiping out the code for double stepping. To copy a 40 track floppy from and 80 track disk was done using special software. You would tell the software which drive was 40 track and which was 80 track, then place 1 40 track floppy into the 80 track drive, the program would copy from the 80 track to the 40 track drive. Writing a 60 track floppy with an 80 track was feasible, however it should be a blank disk. The tracks on an 40 track floppy are twice as wide as an 80 track floppy. Writing 40 tracks to an 80 track floppy means on half of the track is written to. That means reading it would be reading the new data, but also possibly un-erased old data at the same time. That however brings me to my problem. I would love to have a GOTEK if it can assign it as drive 4 and 5. This is easy with physical drives as drive select 3 becomes the side select, and drive select 0, 1, and 2 remain drive selects for drives 0, 1, 2. Select 0 selects both drive 0 and drive 1 with the side select determining which "drive". The same for drive select 1 only it selects drive 2 and 3, and drive select 2 selects drives 4 and 5. Having the GOTEK know which drive is selected by decoding the drive select. This would allow me to assign a separate floppy image to each drive, or have one large floppy image that contains each side of the floppy. In a CoCo 1, 2, or 3 that would mean two directory listings each on track 17 with the drive 3 selector telling the GOTEK which one to use.

Thanks for the video - i flat out cannot get this to work. I ordered one off of eBay from NESynth that was supposed to work with the Coco…. It didn’t. I noticed it was the “new version” CPU, so flashed it to FlashFloppy. Flash Floppy shows up on the oled, i can select a disk on the oled, but i can’t get it to work. All I get is “IO Error” from my Coco. I’ve tried multiple cables, two different controllers and it just flat out doesn’t work. I have a physical floppy that works great and used the same controller and cables and all I can get out of this thing is “IO Error”… anybody have any suggestions? I have an a CocoSDC that works great, but I’d love to tandem this with my physical drive to make copies….

They did not use IDE in those days. Floppies were FM/MFM devices.

Do you have an MM/1? Trying to get my MM/1 to work with the GoTek as /d1 under OS9/68k Ver 2.4

Very nice video :) Thank you for making it :)

Great video! Will be a good resource for other Tandy Radio Shack Color Computer users!

Good video. I've got real floppy drives and also a CoCoSDC, but I've also wanted to try a GoTek and just haven't shelled out for one yet. Just to nitpick a bit, IDE stands for Integrated Drive Electronics, and it refers to hard drives, not floppy drives. In particular, IDE drives have a 40-pin interface (the standard floppy interface used on the CoCo and elsewhere has 34 conductors). They are a development of the preceding ST-506 interface, but Integrated the Drive Electronics (ie, the hard drive controller card) onto the drive itself. The IDE interface has similar signals to a subset of the PC/AT bus, so that the remaining interface between an AT class computer and an IDE hard drive is minimal. After SATA drives came out, the old IDE drives were retroactively named PATA, for Parallel ATA. ATA, or AT Attachment was another name associated with IDE hard drives or optical drives. What makes things a little confusing is that the 34-pin connectors you crimp onto a ribbon cable for a floppy drive interface are called IDC, or Insulation Displacement Connectors, because when you crimp them on, little blades displace the plastic insulation to make contact with the conductors in the ribbon cable. Also, the CoCo uses a flat ribbon cable (no twist), and uses the actual Drive Select jumpers on the drives to select which drive is 0, 1, or 2. These jumpers were present on all the old drives, though for some incomprehensible reason, IBM chose to jumper them all to drive 1 and hack up their cables with a twist, just to make things unnecessarily complicated. Later floppy drives cheaped out and eliminated the jumpers, hard-wiring them all to drive 1. Some earlier, and less cheapo 3.5" drives still included drive select jumpers or switches. I know that my original CoCo floppy drive cable was just straight through, anyway, so it didn't matter at all which connector you plugged into what drive, just as long as the drive select jumpers were set the way you wanted them. I have heard that some floppy cables had missing pins that were used for drive select purposes. If your card edge connectors are specific to D0 or D1, maybe that's why. Does the GoTek have Drive Select jumpering? Is that what the jumper blocks do on that drive?

Good job! Thank you for making the video :) Will be a great resource for other TRS-80 Color Computer (CoCo) users!

Do we have tools for flux with it? :D

when you saved the changed FF.cfg file. how do you implement it?

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