Thanks,
tjb

This post was submitted by tjb.

I finally finished my review of Roger’s Drive Pak and CoCoNet. It’s all here with videos (GR2K is a yawner due to load time…). If you’re considering getting one of these cool new devices, go take a look. Hopefully the info there will help you make the right decision for your needs.

Brian

2. Take a 20-Pin Socket and snip off all pins EXCEPT: 1,2,4,9,10,19,20.

3. Bend the following pins of the socket straight out: 1,2,4,9.

4. Place the socket atop IC1 (74LS245) and solder pin 10 to pin 10, pin 19 to pin 19 (which is bent out on IC1) and pin 20 to pin 20.

5. Solder a wire from Pin 2 of the socket to either the PCB hole where Pin 19 of IC1 was snipped from or to Pin 52 of IC6.

6. Solder a wire from Pin 1 of the socket to pin 9 of IC4.

7. Solder a wire from Pin 4 of the socket to pin 11 of IC4.

8. Solder a wire from Pin 9 of the socket to pin 3 of IC4.

9. Install the PAL chip into the socket (pin 1 to pin 1 orientation).

10. Put everything back together and the MPI should now be 100% Compatible with the Tandy CoCo 3 Upgraded 26-3124 MPI.

Enjoy! -John

Name 26-3124 M.P.I. Upgrade ;
PartNo GCC-3124.01 ;
Date 6/1/2010 ;
Revision 01 ;
Designer J&R ;
Company GIMEchip.com ;
Assembly 26-3124 M.P.I. Upgrade PAL for CoCo 3 ;
Location U1 ;
Device g16v8 ;
/* ***************************************** INPUT PINS **********************************************/
PIN 01 = !CTS; /* Cartridge Select Signal */
PIN 02 = !DBEN_IN; /* Original !DBEN Signal */
PIN 04 = A7; /* Address Line A7 */
PIN 09 = !SLENB; /* Input To Disable Device Selection. */
/* ***************************************** OUTPUT PINS *********************************************/
PIN 19 = !DBEN_OUT; /* New !DBEN Signal – Active LOW – Enables The Multi-Pak Interface Data Buffer */
/* ***************************** LOGIC EQUATIONS & VARIABLE DEFINITIONS ******************************/
DBEN_OUT = CTS # SLENB # (DBEN_IN & !A7); /* Active LOW on CTS or SLENB or (DBEN_IN and not A7)*/
/* ***************************************************************************************************/
/* 26-3124 MPI Upgrade #2, Using a PAL (GAL 16v8) (c) 01 JUNE 2010 by J&R of GIMEchip.com. Enjoy! */
/* 1. Snip pin 19 of IC1 (74LS245) close to the P.C.B. and bend it up so that it sticks straight out.*/
/* 2. Take a 20-pin Socket and snip off all pins EXCEPT: 1,2,4,9,10,19,20. */
/* 3. Bend the following pins of the socket straight out: 1,2,4,9. */
/* 4. Place the socket atop IC1 (74LS245) and solder pin 10 to pin 10, pin 19 to pin 19 (which is */
/* bent out on IC1) and pin 20 to pin 20. */
/* 5. Solder a wire from pin 2 of the socket to either the P.C.B. hole where pin 19 of IC1 was */
/* snipped from or to pin 52 of IC6. */
/* 6. Solder a wire from pin 1 of the socket to pin 9 of IC4. */
/* 7. Solder a wire from pin 4 of the socket to pin 11 of IC4. */
/* 8. Solder a wire from pin 9 of the socket to pin 3 of IC4. */
/* 9. Install the PAL chip into the socket (pin 1 to pin 1 orientation). */
/*10. Put everything back together and the MPI should now be 100% compatible with the Tandy CoCo 3 */
/* Upgraded 26-3124 MPI, with the address range limited to $FF40-$FF7F, SLENB*, CTS* */
/* ***************************************************************************************************/

Thanks,

Wal.

This post was submitted by CocoWal.

Thanks,

Wal.

This post was submitted by CocoWal.

Thanks.

This post was submitted by mikedubya.

This post was submitted by dentman42.

One device that can plug directly into the 2×6 header is A7′s EB301 bluetooth module.  In fact, in a Deluxe Wireless Pak, the header and module are mounted inside the case. The other device to arrive soon is the 2 GIG memory module which will be used as a simultaneous Disk BASIC and OS-9 drive system.

All pak models use the 6551 ACIA to communicate with either a bluetooth radio module or 2 GIG MicroSD drive module. The image below shows an external style serial pak with an EB301 module plugged in.  A regular Wireless Pak would have this module inside the case.

The photos suggest that this is a SparkFun EB301 when it’s actually a product of the A7 corporation.

This gadget was definitely late arriving in the CoCo world.  We needed this baby back in the 80′s or 90′s, for sure.

The Deluxe Wireless RS-232 Pak was designed to be a drop-in replacement for the Tandy Deluxe RS-232 Pak.  No Disk BASIC or OS-9 software should know the difference. Now, instead of stringing a long null-modem cable over to your PC, you can plug a bluetooth dongle or adapter into your PC and establish a wireless connection between the CoCo and PC.  After that, anything is possible.

• Compatible with the Dragon and all CoCo models
• The CoCo can use the wireless pak without a Multi-Pak Interface
• Built-in ROM Firmware (modified copy of Tandy Deluxe RS-232 Pak ROM)
• Using two paks, two CoCos will find each other and connect automatically
• Speeds up to 115200 bps or 230400 bps if the crystal is doubled
• Configure the pak using English commands
• Pak is pre-configured and ready to use out of the box

Please visit the Products page on this site to purchase your own wireless pak.

Here is a video of one user using his CoCo to connect to a Linux box that has an internet connection.

www.youtube.com/watch?v=ueowCfiTZ5s

This video shows a multi-player game being written and tested using two CoCos.

www.youtube.com/watch?v=W-NiaxW4siw

I started this list on CaptCPU’s forum ages ago. Then it was hacked and lost forever, so I figured I restart it here since I’ve found a some of my already tested units. As I find more of them, I’ll add to this article. While working on my repack project, I had tested numerous 3.5′s for CoCo use and here’s what I found:

This WEBSITE is a good place to look up floppy drives and see what type they are. There’s no jumper info, but, if you have the mfg and model number of the drive, you can look it up here and find out what density it is.

Sony MPF920-F (1.44MB from an HP) – has a jumper to select D0 or D1 (unit tested and worked as both)

Panasonic JU-257-133P (1.44MB) – has a four position switch for use as D0-D3 (Tested and worked as all)

Epson SMD-300 (720k) – The picture below is for the SMD-300 and 1.44MB SMD-340:

SMD-300 Jumper Setting

Chinon -FZ-357 – This is the best I could find on this drive and it leaves a lot to b desired…):

As I dig out more FDD’s I’ll check them and post what info I can find on them.

_________________________________________

1/18/10 – Update

I did some digging and found some more of my floppy drives to test. Here’s what I got:

Epson SMD-1340 – 3.5″ 1.44 MB FDD – has a place between the ribbon connector and power connector to solder jumpers for setting drive numbers. Worked as Drive 0 and 1.

Mitsumi/Newtronics D359T3 – 3.5″ 1.44 MB FDD – Has a block of jumpers between the drive motor and the ribbon connector to change several drive settings including drive numbers. Worked for Drive 0, 1 & 2.

I have two variants of the TEAC FD-235HF:

First – 6240 – 3.5″ 1.44MB FDD – Single jumper between the motor and power connector to set drive 0 or 1 – works as either.
Second – 3240 – 3.5″ 1.44MB FDD – a gaggle of jumpers between the motor and power connector for setting numerous drive features, including drives 0 – 3; worked as all.

Last, Citizen OSDA-39E-U – 3.5″ 1.44MB FDD – has a toggle switch between the motor and ribbon cable for set Drive 0 or 1; works as either.

And finally, a nice little document I stumbled on while Googling the jumpers settings for one of these drives. It looks like a chapter out of a book, but, it has many popular 3.5″ drives in it (including some I’ve tested), and it has the jumper settings for these drives to help us set proper DS selections for use with our beloved CoCo’s.

3.5″ Floppy Jumpers

Brian

This is Cloud-9‘s impressive and popular SuperIDE Interface cartridge supporting CompactFlash memory cards, IDE devices, and much more! You owe it to yourself to visit their website and learn more about this cool cartridge and their other CoCo products.

SuperIDE Interface Documentation FAQ IDE And CompactFlash For Your CoCo!This revolutionary new CoCo product from Cloud-9 brings a plethora of storage options to your Color Computer! Hook up any IDE drive or CompactFlash device to your CoCo for use under Disk BASIC or NitrOS-9! The SuperIDE interface is the first mass produced product for the CoCo to utilize high-density parts which draw very little power. Another CoCo First: the SuperIDE also features FOUR software/hardware selectable banks of user-programmable FLASH! No more burning EPROMs, no more opening the case. With the provided software, you can easily flash any image into one of the 16K banks. Put your favorite DOS or even a ROM Pak into a bank and instantly load it onto your Color Computer! Standard Features Supports hard drives and CompactFlash devices On-board CompactFlash socket 40 pin IDE connector 64K of user programmable FLASH Supports NitrOS-9 and Disk BASIC (using HDB-DOS) Employs latest in chip technology for low power draw and upgradability Comes with FLASH programming software and test utilities under Disk BASIC Optional real-time clock SuperIDE Specifications Feature Description Connectors 40 pin IDE and CompactFlash Socket Memory 64K of internal FLASH Software IDE and FLASH programming utilities

Can’t find a CM-8 RGB monitor for your CoCo 3? Have no fear… Roy Justus is here. This guy has created an extremely cool RGB to VGA converter box! The video output is very nice and colorful. Pictured here is one of CoCo3.com’s newest wide-screen ‘VGA’ LCD monitors hooked up to a CoCo 3.

No problem!

For more information including photos and reviews, and to contact Roy, visit this site .

Learn More

For now, this page will be divided into three sections: one dealing with CoCo floppy controllers, the second with CoCo floppy drives, and the last containing information pertaining to the use of non-Tandy drives with the CoCo. Note that this page is in its earliest stages, and is nowhere near complete at this time. The primary goal of this page, at least initially, is to answer some of the common questions about interfacing various drives (particularly those from the IBM-compatible world) to our beloved CoCo.

Tandy offered floppy drives for the CoCo in various packages. Each of these included a controller cartridge which plugs into the computer’s system bus, as well as an external case with a floppy drive mounted in it. The controller cartridge (or ‘pak’) contains one of several Western Digital floppy controller chips, the Disk BASIC ROM chip, and the necessary interface logic. The drive unit contains a linear power supply and a 5.25″ single-sided (in most cases), double-density, half-height (in most cases) floppy drive. A captive (in most cases) ribbon cable exits the drive unit, terminated in a 34-pin card-edge connector which attaches to the controller pak. The drive unit also has an AC power cord. Even though the drives and controllers were sold as packages, they can be interchanged almost universally.

CoCo Floppy Controllers

26-3022

This first model of CoCo floppy controller was packaged in a long cartridge, and was introduced for use with the original CoCo. It uses a WD1793 controller chip, which requires +12V DC. For this reason, a multi-pak interface (or other source of +12V) is required to utilize this controller with a CoCo 2 or CoCo 3. This controller also uses an analog data separator circuit, infamous for its inherent unreliability. However, this controller is the only one capable of being modified (though with considerable difficulty) to allow use with high-density 3.5″ floppy drives.

All subsequent controllers use the WD1773 controller chip, do not use the unreliable analog data separator, do not require +12V (so they will work with any CoCo model), and are capable of double-density operation only.

26-3029

This model was introduced for use with the CoCo 2 (as it lacked the original CoCo’s +12V power supply), and is also mounted in a long cartridge.

FD-500 (26-3129)

This model is also mounted in a long cartridge. It appears to be identical to the 26-3029, with the exception that it carries the Tandy name rather than the TRS-80 name.

FD-501 (26-3131)

One of the more ‘modern’ controllers (mounted in a shorter cartridge than the older ones), this is also the only Radio Shack model ever to feature gold-plated card-edge connectors. Due to the much higher reliability of gold contacts over tinned PC fingers, this is my personal favorite among all of the Radio Shack controllers. This model was introduced in the 1986 Radio Shack catalog.

FD-502 (26-3133)

This is the last Tandy controller. It reverted back to mere solder-tinned edge connectors, for whatever reason (cost?!). Unlike every previous model, this one uses a 28-pin ROM rather than a 24-pin ROM for Disk BASIC. This model was introduced in the 1988 Radio Shack catalog.

All Radio Shack (and some third-party) CoCo floppy controllers use a pair of 7416 open-collector buffer chips to communicate with the floppy drive(s). These chips can fail and cause various strange symptoms. They may be replaced with 7406 chips, which are more rugged (the 7416 is rated at 15V, while the 7406 is rated at 30V). Socketing the replacement chips makes future replacement much easier, should it become necessary.

CoCo Floppy Drives

26-3022 ‘Color Computer Mini Disk’

These original CoCo floppy drives were gray in color, matching the exterior of the original CoCo (and other early TRS-80 machines and peripherals). They use a 5.25″ full-height TEC (Tokyo Electric Corp.) drive mechanism, infamous (like the mating controller) for reliability problems. The drive unit stands vertically, making it taller than it is wide. It was reportedly capable of accessing only 37 tracks or so physically, prompting Tandy’s incorporation of the 35-track limit into Disk BASIC. These (and all subsequent) drives were double-density and, like all but the very latest model (FD-502), were single-sided. This resulted in a capacity of approximately 160 kilobytes per disk.

26-3029 ‘Color Computer Mini Disk’

This drive model had a white case, but was still a full-height, vertically-mounted assembly. These first two styles have 34-pin card-edge connectors on their rear panels rather than captive ribbon cables. The addition of extra drives required using additional case/power supply/drive units.

FD-500 (26-3129), FD-501 (26-3131)

All subsequent drives were also white in color, but were mounted horizontally and used half-height drive mechanisms. They shipped with a single drive (Drive 0) in the lower ‘bay’, and a blanking plate over the upper opening. These drives could be upgraded to a dual-drive system by installing the second drive kit in the existing case. Note that the kit included, and all dual-drive installations in these cases require, a 12-volt cooling fan. The units run acceptably cool with a single drive, but not with two drives. The 4 cm diameter, 1 cm thick brushless fans (as used on many CPU heatsink assemblies) work well in these cases.

FD-502 (26-3133)

This drive unit is like the FD-501, with two notable exceptions. This is the only Tandy model ever to incorporate true double-sided drives, and its drive power connectors are like those of typical 3.5″ floppy drives rather than those of normal 5.25″ drives. The smaller power connectors are also reportedly wired differently than typical 3.5″ drive connectors. As noted elsewhere, either a patched Disk BASIC or an alternative operating system is required to gain access to the second side of disks. A cooling fan must be installed for safe operation if a second drive is added.

CoCo Use With Non-CoCo Drives

Yes, drives other than those from Tandy may be used with the CoCo. In particular, the common 360K PC drives are CoCo-compatible. To put it into the proper perspective, IBM chose for the PC the same pre-existing floppy standard that Radio Shack chose for the CoCo. Actually, IBM deviated from the standard more than Radio Shack did!

The standard specifies the possibility of up to four drives connected to one controller. All decent floppy drives have four drive selection jumpers, usually numbered 0 through 3 (occasionally 1 through 4). While they were used properly in some early PCs, the standard was still not utilized to its full potential (by allowing only two drives). The CoCo supports all four possible drives. All ‘modern’ PCs use a twisted floppy interface cable, with all drives permanently set to ID 1 (or 2; the second of the four possible choices). The same selection method may be used with the CoCo, but will result in the same limitation of only permitting two drives. The usual selection method Tandy used was different. They jumpered all drive select lines on all drives, and removed all but the desired ‘teeth’ from the edge connectors on the ribbon cable. This is commonly referred to as the ‘dental extraction’ method of drive selection. PC and CoCo floppy drives alike may be connected to their controllers in the proper way, with a straight-through ribbon cable feeding all edge connectors, and the proper use of drive select jumpers on the drives themselves.

Another area in which the PC ‘world’ deviated from the standard is the issue of drive cable termination. The standard specifies that a terminating resistor array shall be installed at the end of the interface cable farthest from the controller, and nowhere else. As with SCSI interface cables, 10base2 networking, and all other RF applications, proper termination prevents reflections and standing waves in transmission lines. CoCo drives typically are (and should be) terminated in the proper manner. The Wintel crowd, on the other hand, decided to eliminate that little additional bit of required knowledge (along with drive selection elimination by twisting the interface cable). What they do is terminate ALL drives; that way, one cannot forget to install the terminator at the proper place. Of course, with only two possible drives in the first place, it does not cause as much of a problem as four terminators would.

Another issue to be aware of is that all drives in a CoCo system must spin up when told to do so by the ‘motor on’ line, and not by their drive select lines. PC drives may be jumpered wrong for CoCo operation. Problems may arise when copying information from one drive to the other, as the CoCo assumes that all drives are spinning while any drive is accessed. No delay is inserted between reading from one drive and writing to another. The name of the jumper which controls this behavior depends on the specific drive.

5.25″ 80-track 720K (‘quad-density’) and 3.5″ 720K drives are also CoCo-compatible, within the preceeding constraints. They are electrically identical to each other. Disk BASIC will only access the first 35 tracks on the first side of any disk, however, so they will still only hold about 160K of information each. Various patches exist to Disk BASIC to allow access to the extra space, and the OS-9 operating system can make use of it as well. Note that 720K 5.25″ drives were virtually unknown on the PC platform (except in the Tandy 2000); they were fairly popular in the CP/M and OS-9 communities.

5.25″ 1.2 meg drives are virtually useless on the CoCo. They are reportedly more like the old 8″ drives than either other 5.25″ or 3.5″ drives. They also spin at a different rate (360 RPM rather than 300). Some may reportedly be jumpered to spin at 300 RPM and function as either 360K or 720K drives, but they would still not be reliable for use with true 360K media (just as they are not in PCs).

3.5″ 1.44 meg drives can sometimes be jumpered to function as 720K drives; one should always use true 720K media when doing so. The previously-mentioned hack for the original 26-3022 controller may make these drives useful (under patched Disk BASIC or OS-9, of course) as true 1.44 meg drives; I have not attempted to implement that hack. UPDATE: supposedly, just the act of using true 720K media (without the high-density hole) will make a high-density 3.5″ drive function as a double-density drive. I intend to confirm this.

Something else should be noted about 1.44 meg 3.5″ floppy drives. I encountered such a drive which appeared to be nonfunctional. Further testing revealed that it worked with 720K disks, but not 1.44 meg disks. I checked the density hole sensor switch, and found it to be good. I then traced the circuit from that switch and found that it connected to one conductor in a small mylar ribbon cable connecting the two halves of the drive’s logic circuitry. It turned out that the ribbon cable was not making solid contact. Disconnecting it from the small connector on the one PC board and reseating it fixed the drive. I have since repaired other bad drives in the same manner.