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CompatiCard IV

Shadow Lord

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Jun 16, 2010
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Hello All,

So I finally got my hands on a CompatiCard IV (w/ BIOS and dip switches). It should arrive in a few days. I did have a few questions for the more experienced guys out there:

1. I read on the IBM Support Site that the CC IV only reads 512 byte sectors and as such it can not read XDF formatted disks. Does this mean that it also does not work w/ the DMF format or programs like 2M/FD Format? Was this ever corrected w/ a BIOS update?

2. Do you need a particular floppy drive to benefit from the higher transfer rates of the CC IV? Or will any std. floppy drive do?

3. Is this card compatible w/ a COPY II PC Deluxe or Copy II PC Deluxe Enhanced Option Board? I would imagine it would be as it is like any other FDC but wanted to check.

Thanks!
 
Since I've probably had more experience with these than most folks, I'll address the questions in order.

The CompatiCard IV is nothing more or less than an NSC PC8477 (earlier ones had Intel 82077AA, before Intel broke the design) controller chip and supporting circuitry with optional BIOS. What makes it different is that it can be configured for various IRQ, DMA and I/O port addresses, leading to some rarely-used neat tricks.

1. Bullstuff. This is mostly a failure in IBM's not dealing with the CC BIOS. The CC IV was the centerpiece of Micro Solution's Uniform product, which reads and writes many different formats, few of which actually use 512 byte sectors. Stick an XDF or DMF disk in the drive and run AnaDisk on it and you'll see that the data reads just fine. As a matter of fact, if you set the controller to 3Fx I/O, DMA 2 and IRQ 6 and disable the BIOS, your own computer will see it as a normal floppy controller.

2. What higher rates? This is a commodity floppy controller. A 2D MFM floppy in a "360K" drive transfers at 250Kb/sec, just as it does on any other PC. The CC IV does give you the capability to transfer data at 1Mb/sec if you have a 2.88M drive.

3. Yes, I use one in my system with DOB.

The biggest values of the CC IV are its ability to use non-standard I/O, DMA and IRQ, as well as being able to read FM-encoded disks. There's also an extra line available on the back connector that allows for assertion of TG43 on 8 inch drives that require it.
 
What Chuck said.

I mainly use mine for 8" FM disk transfers, but it works fine with just about everything, both on the hardware side and on the software side.
 
Chuck(G),

As usual thanks for all the info.

1. Good to know it is a SW problem on IBMs side and not a HW problem. So if I am using only two drives I can use the card just like any FDC w/ DOS 6.22 and Win 3.x. I am assuming I will have to use FD Read as before.

2. As for the speed thing it was a misreading on my part. I thought the card could transfer at faster rates for older formats. A re-read of the manual indicates this is not so (except for the proper settings on single vs. double speed drives).

3. Unfortunately, I only have a regular Copy II PC at this time. So for now I plan to install a 360KB drive as a third drive w/ it. I wonder if I can run two copy ii pc boards in the same system... I'll have to check the info in the manuals!
 
Back in the early 90's, we brought out a product that used up to three controllers (usually standard base controller and 2 Compaticards) so that 3 copies could proceed simultaneously. This worked for 360K, 1.2M and 720K, but 1.44M was dicey, as the bus bandwidth was running near saturation. Tow overlapping copies at 1.44M worked fine, however.
 
I recall you previously mentioning that in another post. It is kind of weird thinking of the bus "being" saturated by such an innocuous task as disk copying.... But then as i have been getting back in to these older systems, and reading archived InfoWorlds, it is amazing how far things have come. BTW: Do you still have any printed manuals (I have the PDF) that you don't need or updated BIOS/drivers for these cards?
 
I still have a small pile of the printed manuals, I think. I'll make a note to include one when I return your PSU.

I don't know what level BIOS or drivers that you have, so I can't tell if anything's "updated".
 
Thanks Chuck. I'll pop in the card as soon as it gets here and figure out the BIOS revision. Another thread on the forum had a link to an updated BIOS but the link is dead now. Like you said for all I know it may have the latest BIOS revison on it already.
 
Chuck (G),

I got the card in today and the BIOS revision on it is 1.02. I couldn't check out the driver versions as they came on a 5 1/4" disk and I have to dig my drive out of storage. I know there was at least a 1.05c BIOS update from my googling around but couldn't find any info as to what was fixed or made better. Do you have any info? Thanks!
 
Chuck (G),

I got the card in today and the BIOS revision on it is 1.02. I couldn't check out the driver versions as they came on a 5 1/4" disk and I have to dig my drive out of storage. I know there was at least a 1.05c BIOS update from my googling around but couldn't find any info as to what was fixed or made better. Do you have any info? Thanks!

I don't think I've ever seen much detail on what went into the various revisions. If you can burn an EPROM, I can post an image of a 1.05 BIOS.
 
Chuck(G),

That would be great. I don't have a programmer myself. But I believe one of my friends has access to one. I'll try and looking up the driver versions tonight but my guess is like many old companies they probably never updated their drivers! Thanks.
 
Sorry to resurrect an old thread but I did not want to clutter the board w/ a new post:

I am a bit confused. I thought that if the CCIV BIOS was enabled I could boot off of any attached drive (i.e. both 3.5 and 5.25"). Did I misunderstand this? I can boot fine off of A: drive which is the 3.5" but I can not boot off the 5.25" B: drive. The other benefit of the BIOS I thought was the fact that it supported 2.88MB drives. So what happens if the PC BIOS only support 1.44 and 720 drives? Does the system see the correct size drive or will there be compatibility issues? Thanks.
 
SW1-8 enables "auto-boot". The CCIV will read each drive in succession until one with a valid DOS boot sector is read (that can include "non-system" disks, so be careful). When it finds one, it boots the system from it.

2.88MB drives are supported, regardless of the PC BIOS. Just set the configuration switches appropriately. (on+on for each drive). The CCIV BIOS essentially replaces the PC BIOS for floppy access.

Be sure that the CCIV is configured as the primary FDC (Port 3Fx, IRQ 6, DMA 2).
 
SW1-8 enables "auto-boot". The CCIV will read each drive in succession until one with a valid DOS boot sector is read (that can include "non-system" disks, so be careful). When it finds one, it boots the system from it.

2.88MB drives are supported, regardless of the PC BIOS. Just set the configuration switches appropriately. (on+on for each drive). The CCIV BIOS essentially replaces the PC BIOS for floppy access.

Be sure that the CCIV is configured as the primary FDC (Port 3Fx, IRQ 6, DMA 2).

Chuck(G) I have the card configured as the primary FDC but I have to double check the switch. The reason I ask about the BIOS is related to another problem I had. The Everex MOBO does not have a built in FDC. However, the BIOS/ECU has an option to define the floppy drive type for A: and B:. On the CCIV I have A: as 1.44 and B: as 1.2. However, in the ECU it was reversed and when I tried to access disks it would error out. Switching it in the ECU so A: was 1.44 fixed the problem.

I am not quite sure how does the ECU/BIOS on the MB interact w/ the BIOS on an add in FDC? After all the Everex doesn't even have a FDC so why would it have FDC code/functions in the BIOS? And if defining the wrong type interferes with access then would defining "no drive" disable access? I, unfortunately, don't understand the behind the scene interactions well enough to understand what is going on here.
 
All motherboards (with the exception of very recent ones) have BIOS code for floppies (and even some of the more recent ones can boot from a USB floppy). But even the original 5150 had floppy code in the BIOS.

You might try telling the ECU BIOS that you have no floppies and see if the CCIV will take over.
 
All motherboards (with the exception of very recent ones) have BIOS code for floppies (and even some of the more recent ones can boot from a USB floppy). But even the original 5150 had floppy code in the BIOS.

You might try telling the ECU BIOS that you have no floppies and see if the CCIV will take over.

Okay I will try that either tonight or tomorrow. However, I still don't see how this works. I.E. does the BIOS from the CCIV step in and take over by overwriting the sections on the MB BIOS related to floppy control? Or does it just intercept the calls? With the Adaptec the system loads what it calls an "optional ROM" (Everex's "English" translation of the code generated when the BIOS from the SCSI controller is initialized) I guess what I am asking is how did the original designers of the PC envision this working.
 
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