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I think I figured it out: head pressure. After gently putting extra finger pressure on the top head the drive was able to complete a successful write. From what I can find, there is a screw that runs into the neck of the arm that holds the head, on the back is a spring. I tried to turn the screw...

With more testing my cable seems fine as per Deramp's cable page 3. I can write double sided single density just fine, which to me means the top head works. Is it possible if the top head is rotated radially a few degrees that FM (single density) works but not MFM (double density)? here is a...

I guess I will start using IPA. I hooked the 8" floppy drive up to a 486DX with Dos. Although 22disk will format, it will not copy complaining about sector not found. I set the BIOS to 1.2M 5 1/4 drive and dos can format and copy onto and off of. It won't make a system disk saying there is not...

A few more observations and questions: Should the heads be perfectly aligned to one another? on one drive, the top head is about 20% shifted over from the bottom. The other drive, the head looks rotated about a few degrees - As I look down on the head, the metal the holds the head doesn't look...

I have cleaned the heads with rubbing alcohol (everyone uses IPA, whats the diff?). I thought about head pressure. I pushed a tiny bit on the top head and it instantly scratched the floppy disk. I believe the manual shows using a jig and a dial indicator to adjust head pressure. Does the heads...

With more testing I have a little more information: It seems I can write small files (1k - 2k) correctly. larger files will error out on the first transfer. Attached is a picture of the probes hooked to TP1 and TP2. My ground leads are on TP5. It is interesting to notice how high the signal sits...

An update: I can write double density to the drive, but with a lot of read after write errors. The errors always come from surface 1, which is the top head. I think this rules out a 16FDC problem and it being the drive itself. Maybe it needs an alignment?

I need some advice for a problem I am having. I have an 8" Floppy drive that gives me read after write errors when using DS/DD disks. I have followed instructions on setting up the 16FDC to accept Shugart drives. my drive setup: A: 5.25 half height floppy B: 5.25 Gotek C: 8" Shugart 850/851 (the...

I have figured out what I wanted to know. Everything has been revealed in the Multi-User Basic manual. This manual describes a multi user CDOS version that uses the 64Kz and 16Kz cars with bank selection to run up to 6 users in a CDOS like OS. Has anyone used MU Basic? After I get signed up to...

I have been reading some more and I am still confused. Looking in the 64KZ manual, it shows how to use 16KZ cards with it (banking up to 512K), but does not talk about what operating system. is it possible this is just a theory if people wanted to create their own bank selection? I guess they...

When I am stuck in this situation, I use an oscilloscope and probe pins while you type on keys... the 12volt are signals ready(-12) not ready(+12), and the 5volts are floating waiting for something to pull them high or low.

I am able to boot cromix with this PIICEON card, but I cannot login because I don't have another card, only 16Kz's and the DMB 6400 which is missing a modification for cromix. As much as I want to run Cromix, maybe the IMSAI should use the 16KZ with some static ram and someday maybe I will come...

So CDOS can not and was never designed to use more than 64K of ram? Can Cromix use 16KZ cards?

All of my knowledge is for the Z80 version: I also had to edit this a bunch because I was mixing the 16KZ with the 64KZ cards. This confuses me even more and I guess I have to go reread some documentation. This is what I have learned and please correct me because it sounds like I am wrong: -...

Looks like SB1 was for DOS/disk cache. I still don't know what 2-5 on SB2 do. Also, since E4 is sheered, and from what I have found it should be jumped. I might have to solder a new jumper and try again

I had my first battle with the slave-16 card. I could not get the IMD images to work. I tried 360K and 720Disk, but my IBM PC would not read them. I ended up using the the files in ALLOY.zip. running INSTALL did not go very far. The card asked me if I changed any jumpers on the board. answer yes...

Can you post your autoexec.bat and config.sys files? What IRQ,DMA and base I/O are you using? Sound cards should be IRQ 5, DMA 1, I/O 220h.

I noticed the first picture of ram has parity chips (the IC that is vertical on right side of ram stick). You said you tried different ram, have you tried ram without the parity chip? I also know 386's can be picky about memory density, so trying different ram stick with different chip...

I was looking through ISA cards trying to find info when I came across this post. I have one of these cards also. Thanks for the link to the software. I have owned this card for a while now and have not found more information until today. I'm excited to try this thing out! I will try it out and...

My journey with my IMSAI/Cromemco beast continues. I have recently aquired a 16FDC and some double sided shugart 850 floppy drives. I got tempted to try Cromix and quickly realized it wants more than 64K of ram. Out all of the ram cards I have bought probably won't work with Cromix. I am at a...