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alan8086
August 31st, 2017, 10:27 AM
Hello All - I've been trying to get just one of my three vintage computers to work - in this case, the NEC APC. Mine is a colour version. It worked when I first got it, loaded MS-DOS from the floppy just fine. It stopped working when I foolishly (leave whats well enough alone) decided to clean the drive heads using a cotton bud and meths. Since then, all I get is the initial * which is the POST saying everything is fine and then on loading an OS floppy I get [LOD] and both floppy lights are lit, few seconds later the floppy load solenoid lets go, the 2nd drive light goes out. few seconds later it tried again - solenoid engages, 2nd drive light back on and then I get [LER] which is load error I believe. Once it has said [LOD M] Cant find that one in the documentation. Same symptoms on both drives and with every disk I have.

Have I...

a: misaligned the heads which are delicately held on lightly sprung carriages?
b: all my once usable floppy disks have suddenly been aged to death?
c: damaged the head/s which have damaged/scraped the media surface of all my once useable disks? I've just cleaned the heads again and left a blank floppy running and found no evidence of scoring on the unused disk

I had a go at creating some new DOS-2.11 disks using my DBIT FDADAP adapter (never used it before until now) connected to my Compaq Portable III.The Compaq has MS-DOS 6.22 loaded on the hard drive, a working BIOS battery and a utility to change the BIOS settings on the HD. I connected a straight cable from the Compaq floppy controller to the FDADAP board (no twists) and the controller end of the 50 pin cable from the APC to the connector on the FDADAP, connected a floppy power lead tot he FDADAP - the Compaq cant see drive a: The 8" floppy is powered by the APC and I have the COMPAQ BIOS set to drive A: as 1.2MB Nothing. Perhaps the Portable III was a bad choice for an imaging machine?

Things are not going well! I sound like Marvin from the Hitchhikers Guide!

Any comments or suggestions would be greatly appreciated.

Thanks!

alan8086
August 31st, 2017, 11:13 AM
Oh, does anyone know what the hidden switch at the back of the keyboard is on this machine? Pressing it gets you into some sort of low level monitor with a table of hex codes and a flashing cursor ready for something or other. No OS loaded from floppy is required - just press the button behind the rubber stopper thing in the keyboard plastics and up comes this monitor thing.

tipc
August 31st, 2017, 11:35 AM
Wow I never knew that. I no longer have an APC, used to have 2, now all I have is a set of boards, missing the cpu board. I thought I still had the keyboard, but it's nowhere I can tell. I do have a faint recollection of some kind of blob back there. They should have labeled the blob-thing.

SomeGuy
August 31st, 2017, 11:38 AM
If you have two drives in the unit, you might be able to switch the first and second drives (probably by changing jumpers on the drives). I would not expect both drives to have the same problem.

tipc
August 31st, 2017, 12:00 PM
Those disks won't last forever. The other possibility, though unlikely, the solvent wasn t allowed to.dry completely.

I'm likely the only person on earth who is the proud owner of a Butlet Flats Associates 5 1/4" floppy drive kit for the APC. The drivers are non recoverable though. I do have the dual drive cabinet, horrid shape, expansion card, and instructions. Strangely the card uses a wd1771 chip, or something close, while the APC stock floppy adapter uses the venerable upd765/8272..

alan8086
August 31st, 2017, 12:04 PM
Wow I never knew that. I no longer have an APC, used to have 2, now all I have is a set of boards, missing the cpu board. I thought I still had the keyboard, but it's nowhere I can tell. I do have a faint recollection of some kind of blob back there. They should have labeled the blob-thing.

A revelation! Defiantly a small press to make switch under there! Don't suppose you have any spare memory boards?!

alan8086
August 31st, 2017, 12:08 PM
If you have two drives in the unit, you might be able to switch the first and second drives (probably by changing jumpers on the drives). I would not expect both drives to have the same problem.

I've already tried swapping them round, altered the jumper settings and termination resistors too. Still behaves the same and as you say, it seems unlikely I've wrecked both drives so maybe its a media issue? My efforts to create new media are a flop so far - I shall try my fdadap adapter in a different old PC, I have a first gen Pentium Intel based board I can try other than my Compaq portable III.

alan8086
August 31st, 2017, 12:11 PM
Those disks won't last forever. The other possibility, though unlikely, the solvent wasn t allowed to.dry completely.

I'm likely the only person on earth who is the proud owner of a Butlet Flats Associates 5 1/4" floppy drive kit for the APC. The drivers are non recoverable though. I do have the dual drive cabinet, horrid shape, expansion card, and instructions. Strangely the card uses a wd1771 chip, or something close, while the APC stock floppy adapter uses the venerable upd765/8272..

Its quite possible the solvent didn't dry, allthough it would take time for me to go through all the disks I have and still have residual solvent left.
Parts for NEC APCs must be like hens teeth! Never heard of an external floppy drive, I knew there was an external hard drive. Shame we cant all get together somehow and catalouge our APC parts!?

tipc
August 31st, 2017, 12:17 PM
I could trade you for a cpu board :)

What drive are you attempting to create the disk with? Did you say you never used the adapter before? Dave Dunfield has instructions for building an adapter on his site, if it's still up. ImageDisk, his program, needs at least a 486 to work iirc. That pentium box is likely a better bet.

alan8086
August 31st, 2017, 12:52 PM
I could trade you for a cpu board :)

What drive are you attempting to create the disk with? Did you say you never used the adapter before? Dave Dunfield has instructions for building an adapter on his site, if it's still up. ImageDisk, his program, needs at least a 486 to work iirc. That pentium box is likely a better bet.

I am using one of the NEC APCs 8" drives connected to an FDADAP adapter which connects to my Compaq portable III motherboard.

FDADAP is here http://www.dbit.com/fdadap.html

I've got Dave dunfields Imagedisk on the Compaq, It runs the testfdc component ok. The problem so far is that the Compaq cant seem to see the FDADAP/8" drive in the first place. I have the BIOS set with the A: Drive as a 1.2MB drive but it just gives an error after the POST that the BIOS is not correctly configured. That is what would happen if I set a 1.44mb drive in the BIOS but it actually had a different drive. As far as I know, the 8" drives are 'logically' identical to a 5.25" 1.2 mb drive, so I expected to be able to set it as a 1.2mb drive in the BIOS and it wouldn't notice the difference with an 8" drive connected via the FDADAP adapter.

Nothing so simple!

alan8086
August 31st, 2017, 12:56 PM
I also have a WA1003 ISA mfm hard drive/floppy adapter I could try in my pentium machine which has ISA slots. I know there is a list of compatible ide chipsets on Dave dunfields site - this board isn't there but it may be worth a go if I disable its had drive controller and just use the floppy controller?

tipc
August 31st, 2017, 02:26 PM
Well if I read you you can run imagedisk from a hd floppy. Aawkward but doable. And although this doesn't help your current predicament, you could try connecting a hd floppy to your APC. With some sort of adapter.

alan8086
August 31st, 2017, 02:45 PM
Never thought of attaching a 1.2MB 5.25" drive to the APC - my adapter only goes one way. It should be possible to make a bootable 8" floppy for the APC using an IBM compatible PC, my adapter and one NEC APC 8" drive. That is how everyone else does it and that is what the FDADAP adapter was developed for.

SomeGuy
August 31st, 2017, 03:15 PM
A couple more thoughts: have you checked the voltages to the floppy drives? It could be there is a power issue that is not affecting the rest of the machine. What model of drives are these?

Have you also tried the second drive connected to your PC?

Assuming these are double sided drives and you are using double sided disks, then yes, they should look like 1.2mb drives to a PC. Some machines perform a seek test at boot and will complain the configuration is wrong if that fails.

From the disk images I am aware of, NEC APC disks may be either FM or MFM encoded. So you do need a PC controller that can read and write FM unless you are 100% sure the media you want do deal with is exclusively MFM.


I've got Dave dunfields Imagedisk on the Compaq, It runs the testfdc component ok.
Against the Compaq's drive, or with the 8" dirive?

tipc
August 31st, 2017, 04:51 PM
I was told by Dave himself a 486 is minimal for ID to.work.

Also not all 8" drives are the same. I don't want to discourage you from trying things, but those drives just may not work as other more standard drives do. And if all elae fails you could construct an adapter to attach a 5 1/4" drive. That may not work either, but something should eventually. You may need to appropriate a Shugart drive or have someone who's set up make disks for you.

SomeGuy
August 31st, 2017, 05:23 PM
I was told by Dave himself a 486 is minimal for ID to.work.
That is incorrect. If he told you that, he must have had his wires crossed. I have been using ImageDisk like crazy on a 286 and it has worked fine for me. Perhaps some performance issues in some cases, but it does its job as far as I can tell. I also have it on several 8088 machines.

Now, it DOES require a 100% IBM PC compatible floppy controller that some early clones may lack. For example, one would not (I'm fairly sure) be able to run ImageDisk on the NEC APC itself, even though it can run a port of MS-DOS.

new_castle_j
August 31st, 2017, 07:21 PM
Awesome, another NEC APC owner out there! I powered mine up a few months ago and got it to boot, still more experimenting to try though.

I also use the FDADAP board with my Pentium MMX machine and love it. You mentioned that you are using it with a straight thru cable, on my machine, that puts the 8" floppy as drive B: (given the 8" was originally pinned as drive DS1) In my BIOS I set both drives A and B to 1.2 mb and when starting Dunfield's IMG Disk I set the program to use drive B: and also set double-step to OFF.

I haven't tried making disks for the NEC on my PC, but I could try if it would help you out, let me know.

I also had an experience with an NEC 8" floppy where the grease turns into glue over time, the slides where the heads ride had built up a ball of grease and prevented the heads from fully loading in contact with the disk surface.

I've heard about some nifty CAD programs for the APC, if anyone has the one called "Arthur" I'd like to give it a spin. At some point I think I'll also try TurboDOS on it as there is a disk image on bitsavers.

alan8086
September 6th, 2017, 01:34 AM
....I've tried my FDADAP adapter in my intel / Pentium motherboard and also with the Western Digital WD 1003 adapter - same result, the PC cant see the A: drive, just comes up with 'floppy drive error 40' after the POST cycle. I'm wondering if DBIT have sent me a dud FDADAP adapter? Tried multiple cables too :(

alan8086
September 6th, 2017, 01:38 AM
A couple more thoughts: have you checked the voltages to the floppy drives? It could be there is a power issue that is not affecting the rest of the machine. What model of drives are these?

Have you also tried the second drive connected to your PC?

Assuming these are double sided drives and you are using double sided disks, then yes, they should look like 1.2mb drives to a PC. Some machines perform a seek test at boot and will complain the configuration is wrong if that fails.

From the disk images I am aware of, NEC APC disks may be either FM or MFM encoded. So you do need a PC controller that can read and write FM unless you are 100% sure the media you want do deal with is exclusively MFM.


Against the Compaq's drive, or with the 8" dirive?

....I've tested the voltages to the 8" floppy drives - I'm getting a healthy looking +4.9 -5.0 and +25 as per the PSU specifications in the manual. I did wonder if there was ripple on the DC voltages so I used my ancient analogue oscilloscope. I don't exactly know what I'm doing with scopes but there seemed to be little more than a straight DC line on all 3 voltages, some 'fuzz' if you really zoom in.

alan8086
September 6th, 2017, 01:42 AM
The floppy drives are NEC Model FD1165-A Manufactured 1983. Double Sided Double Density

alan8086
September 6th, 2017, 01:46 AM
406164061740618

...Regarding the hidden switch at the rear of the keyboard. The display reminds me of the COS on an RM380Z - a low level assembly language thingy although I may be remembering wrong as its over 20 years since I last had one.

Ive tried typing 'stuff' and it just returns a '?' on a new line. No mention in any of the manuals except for the existence of the push switch on the keyboard circuit diagram. Little about the APC on the net let alone this switch thingy.

alan8086
September 6th, 2017, 01:47 AM
...Sorry to keep droning on about this machine! Its just frustrating :((

JonB
September 6th, 2017, 01:47 AM
Hi Alan

I think the fuzz on the power lines is normal. I see it all the time on my Rigol DSO.

The switch is interesting. It is obviously dropping into a monitor of some sort.

Now, I may be able to help you image the boot disks. If it is a SS 500k 8" format I may be able to connect the Shugart drive in my Model II to my transfer PC (which has one of the most compatible motherboards listed on Dave Dunfield's IMGDISK site) and do the biz. I've also got a spare DS 8" disk lying around that cost an arm + 1 leg so I could try that as well (if you need double sided), although this has a minor problem (seek to track 0 doesn't work). Where might I download the boot disk image files from?

Cheers
JonB

alan8086
September 6th, 2017, 01:49 AM
https://www.ebay.com/p/NEC-Model-Fd1165-fq-Floppy-Drive-8-Disk-Vintage/1587067061

- WOW! $160! No, I'm not selling... :]

alan8086
September 6th, 2017, 02:00 AM
Hi Alan

I think the fuzz on the power lines is normal. I see it all the time on my Rigol DSO.

The switch is interesting. It is obviously dropping into a monitor of some sort.

Now, I may be able to help you image the boot disks. If it is a SS 500k 8" format I may be able to connect the Shugart drive in my Model II to my transfer PC (which has one of the most compatible motherboards listed on Dave Dunfield's IMGDISK site) and do the biz. I've also got a spare DS 8" disk lying around that cost an arm + 1 leg so I could try that as well (if you need double sided), although this has a minor problem (seek to track 0 doesn't work). Where might I download the boot disk image files from?

Cheers
JonB

JonB to the rescue - again! :} Nice to hear from you again.

There are images for DOS 2.11 + CP/M - 86 + USCD-p on dave's site:

http://www.classiccmp.org/dunfield/img54306/system.htm

It was my intention to get an imaging rig up and running with the NEC Model FD1165-A drives on the APC I have. The only other 8" drives I have are the big Shugart ones off my IMS 8000 S100 unit, they are single sided though I think? As you can see, this is not going to plan! The MS-DOS disk is more important as I have worstar and Multiplan for it, that's if the disks still work anyway. If you want the added headache (on top of the SB board) it would be highly appreciated. I can post some DS DD 8" floppies too if it helps?

By Monitor do you mean some sort of machine code/Hex low level programming environment or am I way off?

JonB
September 6th, 2017, 02:18 AM
To the rescue again? Not so far, your SB is still not booting. :(

Yes, that is exactly what a monitor is. That line of text is showing you the CPU register states.

Some things you might try in the monitor:

d [ENTER]
Might dump a region of memory.

L [ENTER]
Might list (diassemble) a region of memory.

These commands are guesses, so it might do nothing but print the ? again. Give them a go, and other single letter commands. You may find it does *something*.

Don't send any disks yet, I have some DS 8" here I think.

What settings are you using for imgdisk? I had the drive as B: 720k 3.5" (in the BIOS) and in Imgdisk B: Single Sided (use double for yours) Double step OFF. My settings allowed me to transfer a single sided TRS-80 Model II boot disk image to the 8" drive. I used 22DISK to verify (with the BIOS setup as B: 1.22M / 5.25") - yeah, I know, odd; but that is what I wrote in my notes.

There will be some delay so do not rely on me getting this done any time soon. Your SB is still on the bench and setting up the Model II and PC to transfer disk images takes ages, and is very disruptive in my study.

Finally.. those drives sure do look sweet! I bet they are less klunky than the Shugart ones.

Cheers
JonB

alan8086
September 6th, 2017, 02:30 AM
...The APC drives are defiantly an advance on the Shugart ones - still loud and clunk though. The shugarts on my IMS 8000 have more 'charm' however!

I didn't get very far with imagedisk - I assumed if the floppy drive detection fails at the POST then it aint gonna work? I could be horribly wrong however. In the PC BIOS I have the A: drive set at 1.2MB floppy, it then flips an error after its detected all the IDE devices. Once inside DOS, changing to the A: drive from C: results in Abort Retry Fail and if I run Dave Dunfields Testfdc program, it just skips and aborts all the tests. Am I going on incorrect assumptions here? Perhaps in my bumbling methodology, if I actually ignored all that and just run Imagedisk, will it work regardless?

alan8086
September 6th, 2017, 02:31 AM
Oh, just tried the D and L as well as all other letters in the monitor - just get a ? every time. Thanks for satisfying my curiosity though!

No hurry with any disk imaging you may do. I understand lack of space issues. I only have tons of it as I rent an empty shop in town. Really must do some actual work though....

JonB
September 6th, 2017, 02:51 AM
I get drive detection fails too. However, I was still able to create boot media. Try it, you might be lucky.

I assume you used DD's drive wiring schematic to build a 34 - 50 way drive adapter?

There is also this: https://oshpark.com/shared_projects/Hr1FTWxB which was done by Forum member NF6X. I don't know if it is bi-directional though - it is designed to allow connection of a 34 way floppy drive (5.25" or 3.5") to a controller that has a 50 way Shugart adapter pinout. You could try to put the boot image onto a 3.5 or 5.25 inch disk and use one of these to connect the disk to the machine. At least you could use this to get the machine up and running. I use it on the Model II with an HxC FDD emulator. No imaging of floppies required.

I have a spare...

alan8086
September 6th, 2017, 03:11 AM
...I assume you used DD's drive wiring schematic to build a 34 - 50 way drive adapter?...

...No one must have heard of the FDADAP adapter from DBIT? I looked at Dave's adapter and opted to spend $40 on this:

http://www.dbit.com/fdadap.html

https://www.youtube.com/watch?v=6ODv48t-Ya8

...it handles the TG43 signal, supposedly, when I can get it to work. I though it would be a neat solution. Don't think its bidirectional so I cant try a 1.2MB 5.25" drive on my NEC APC.

JonB
September 6th, 2017, 03:16 AM
No, but you could use the adapter card I linked to.

The Shugart drive worked fine without TG43 when I was imaging for the Model II.

http://nemesis.lonestar.org/computers/tandy/hardware/model16_6000/floppyfix.html <- this has a lot of info on adapting 50 way to 34 way Shugart interfaces.

alan8086
September 6th, 2017, 03:19 AM
'I have a spare... '

The OSH Park thing looks like what I was planning to make before I got the FDADAP adapter. No logic involved, just holes and traces on a double sided PCB. I even bought the DS copper clad board off eBay and found all the correct connectors from my piles of e-waste! I have an emotional/financial investment in the FDADAP adapter I paid $40 for, I'll not give up just yet! When I do, ill probably just try building D Dunfields adapter like everyone else probably does.

ldkraemer
September 6th, 2017, 04:50 AM
Alan8086,
In the Video with the FDADAP, and the Kyroflux, you are using a IBM Style twisted cable from the Kyroflux and the FDADAP Board.
That swaps Conductors 10 thru 16 from the Kryoflux. Also, what you might not know is that when using a IBM twisted cable, with an
IBM Controller, there are two Motor ON Signals (10 & 16 are BOTH Motor ON). I'm sure that is what is causing your problem, as the
Kyroflux doesn't have the Dual Motor ON Signals.

You need a straight though cable, or another connector squeezed on your Kyroflux cable (before the twist). Then try your Interface with the Kyroflux.

40622

Larry

alan8086
September 6th, 2017, 05:25 AM
Alan8086,
In the Video with the FDADAP, and the Kyroflux, you are using a IBM Style twisted cable from the Kyroflux and the FDADAP Board.
That swaps Conductors 10 thru 16 from the Kryoflux. Also, what you might not know is that when using a IBM twisted cable, with an
IBM Controller, there are two Motor ON Signals (10 & 16 are BOTH Motor ON). I'm sure that is what is causing your problem, as the
Kyroflux doesn't have the Dual Motor ON Signals.

You need a straight though cable, or another connector squeezed on your Kyroflux cable (before the twist). Then try your Interface with the Kyroflux.

40622

Larry

Thanks for your reply Larry - I should have mentioned it, that youtube vid isn't mine. I just put it there as an example of the FDADAP adapter in action as no one seemed aware of it. I don't have the kryoflux, just the fdadap. I've tried straight cables, cables with the twist, cables with the a: And b: Plug but plugging in the B: Plug into the fdadap because its got no twist. I might just be the old cables I have! Eventually I may hit on the correct combination of parts!

SomeGuy
September 6th, 2017, 05:52 AM
I didn't get very far with imagedisk - I assumed if the floppy drive detection fails at the POST then it aint gonna work? I could be horribly wrong however. In the PC BIOS I have the A: drive set at 1.2MB floppy, it then flips an error after its detected all the IDE devices. Once inside DOS, changing to the A: drive from C: results in Abort Retry Fail and if I run Dave Dunfields Testfdc program, it just skips and aborts all the tests. Am I going on incorrect assumptions here? Perhaps in my bumbling methodology, if I actually ignored all that and just run Imagedisk, will it work regardless?
Imagedisk actually does bypass the BIOS, so it *might* work even if BIOS is not happy. It depends on the actual problem. You may need to pass a parameter to ImageDisk and TestFDC to specify the physical drive number since it may not know what the DOS drive letter is now.

See how far you can get. Does the drive light come on? Does the head move?

alan8086
September 6th, 2017, 06:08 AM
Imagedisk actually does bypass the BIOS, so it *might* work even if BIOS is not happy. It depends on the actual problem. You may need to pass a parameter to ImageDisk and TestFDC to specify the physical drive number since it may not know what the DOS drive letter is now.

See how far you can get. Does the drive light come on? Does the head move?

Hmmmm, think I will have to start again with this. That's quite clever if it bypasses the BIOS. The drive light seems to come on when you close the door with a floppy inside. The head load solenoid also activates, no head stepper activity though. Not sure if that means 'intelligence' or would it do it with just power and no data connection to the drive.

I've packed it all away for now as its time I did some actual work. I'll have another go later and report back.

Thanks for all of your responses ��

alan8086
September 7th, 2017, 04:34 AM
Ok, its towel throwing time.

I have before me one VX Pro motherboard with Pentium 133MHz cpu, 170MB HD with DOS 6.22 loaded etc etc

I have straight ribbon connectors from the board floppy controller to the FDADAP adapter and from that to my NEC APC 8" drive

In no way can I get the PC to communicate with the 8" drive.

I've tried also my WD1003 controller - no different although it works fine with a 1.2MB and 1,44MB drive so at least I know it works.

Ive started IMD (imagedisk) - entered some settings - A: Drive Cylinders: 77 Sides: Two Double Step: Off (guestimate) Sectors Per Track 8 Start Sector: 1 Speed: 500Kb/s FM Sector Size: 1024

Tried to run a format...

Insert Disk, press enter - It just displays the above settings and says Format Error <0> WriteProt - Fatal Error

It must be me???

SomeGuy
September 7th, 2017, 06:33 AM
Does the drive light activate? Does the head move? (Never bothered with the format option in IMD since it automatically formats when it writes images, but I would expect it to try and seek track zero)

What exactly happens when you try reading a disk?

Also, remember that the write protect notches on 8" disks work the opposite of 5.25" disks. You put a tab on it to enable writing if it has a notch.

tipc
September 7th, 2017, 07:42 AM
You did try swapping the drives iirc, so the problem wasn't that the drives were bad to begin with?

I hope you get this working. Besides my Canon As-100 8" drives, the NECs are the only set I still have. Remember don't rule out putting hd floppies in the APC. I can't remember if my external 5 1/4" drives were bootable. Makes no difference anyway, I don't have drivers, so if I ever decide to write my own I could always make it so.

Clearly you could try another mobo and/or floppy controller. The native APC floppy ic is the NEC upd765 so we're not dealing with an unconventional setup. But then there's the bios ...

alan8086
September 7th, 2017, 10:05 AM
Does the drive light activate? Does the head move? (Never bothered with the format option in IMD since it automatically formats when it writes images, but I would expect it to try and seek track zero)

What exactly happens when you try reading a disk?

Also, remember that the write protect notches on 8" disks work the opposite of 5.25" disks. You put a tab on it to enable writing if it has a notch.

The drive light activates as soon as you pinch the door shut, and the solenoid lowers the heads onto the disk surface. It does this in any circumstances so long as a soft sectored disk is inserted. tried it with a hard sectored disk and the lights do nothing.

Write protect notches are the opposite of 5.25" drives - notch covered = write / notch uncovered = write protected - I've tried both :(

When trying to format a disk, nothing happens to the drive, I get this on the screen - Format Error <0> WriteProt - Fatal Error - and nothing happens on the 7 segment display on the FDADAP adapter, except one time when it displayed '4' !!

alan8086
September 7th, 2017, 10:17 AM
You did try swapping the drives iirc, so the problem wasn't that the drives were bad to begin with?

I hope you get this working. Besides my Canon As-100 8" drives, the NECs are the only set I still have. Remember don't rule out putting hd floppies in the APC. I can't remember if my external 5 1/4" drives were bootable. Makes no difference anyway, I don't have drivers, so if I ever decide to write my own I could always make it so.

Clearly you could try another mobo and/or floppy controller. The native APC floppy ic is the NEC upd765 so we're not dealing with an unconventional setup. But then there's the bios ...

I've tried both drives - are terminating resistors meant to get hot by the way? They are the white ceramic type in sockets. I'll try another motherboard. I'm just surprised that there is no head movement whatsoever from the drives, unless somehow I have destroyed both? I am wondering if my adapter is the problem. Maybe time to make one myself.

SomeGuy
September 7th, 2017, 11:00 AM
The drive light activates as soon as you pinch the door shut, and the solenoid lowers the heads onto the disk surface. It does this in any circumstances so long as a soft sectored disk is inserted. tried it with a hard sectored disk and the lights do nothing.
Wait... and stays on? That is not right.

What happens if the FDADAP is completely disconnected? The light should NOT come on.

You don't have the cables backwards do you? Re-check that pin 1 really matches up everywhere (regardless of cable marking and polarization notches, which are sometimes wrong).

Otherwise it sounds like something is seriously borked in either the FDADAP or both of the drives.

I'd test the drive by itself, when disconnected from an interface the drive light should stay off. If you touch a wire between the ground and the appropriate drive select pin the drive light should come on.

alan8086
September 7th, 2017, 11:26 AM
...tell you what, I'll make a video of my setup and what the drives do in the APC and what they do in my imaging setup. The FDADAP has a tiny '1' to one side of the solder side of the 50 pin and both 34 pin sockets, in the mask if that's what you call it. I have the ribbon cables so the red wire is aligned with the '1'. I haven't tried the other way round although its worth a go? Having them incorrectly aligned would certainly explain a lot! this adapter didn't come with a manual, although it should be too straightforward to need one!

harry
September 7th, 2017, 12:18 PM
If its a help, I can post you one of my working disks ...CPM/86 which boots my machine no problem, then at least you will have a known working disk, I would have thought any damage to your original disks would be quite evident if done by scoring with the drive heads. If the APC worked prior to you cleaning the drives, did you remove the drives for servicing, or try cleaning them in situ? I like to remove drives,to get at all moving parts for cleaning and lubricating and check and clean all connections.
pm me If I can help.
...Harry

alan8086
September 7th, 2017, 12:32 PM
Hi Harry, yes I removed the drives and unscrewed the metal rf shield plate to get to the drive heads. That's a kind offer - having a working floppy would certainly be of use, cut a long story short at least! I can send you a replacement blank disk too? I'll try and work out how to PM you :) Oh I'll cover any postage cost also. It would be nice to re visit CP/M too!

alan8086
September 8th, 2017, 04:39 AM
Harry has very kindly promised to post an APC CP/M-86 disk. To console myself until it arrives, I used my Compaq Portable III, one of my Intertec Superbrain floppy drives and D Dunfields Imagedisk to make a Superbrain boot disk! It reported success. No idea for sure as I do not yet have a working Superbrain as JonB is performing surgery on it - It felt good though!

harry
September 8th, 2017, 05:17 AM
Disk was packed and posted today, I hope you receive it soon , undamaged!
best of luck,
Harry

alan8086
September 8th, 2017, 06:39 AM
Disk was packed and posted today, I hope you receive it soon , undamaged!
best of luck,
Harry
Brilliant! Thankyou!

alan8086
September 9th, 2017, 01:40 AM
Disk was packed and posted today, I hope you receive it soon , undamaged!
best of luck,
Harry

Damnaggit! Managed to miss the post this morning, something has arived, likely yiur disk Harry, have to wait until monday now :(

alan8086
September 9th, 2017, 03:09 PM
SUCCESS!!!!

4067140672


https://youtu.be/NMiSFlffNn8

Oh the Joy!!

alan8086
September 9th, 2017, 03:13 PM
Thanks again to you all and to Harry for supplying the CP/M-86 disk.

regarding the disk, I have a confession regarding why the video shows an MS DOS listing and not CP/M - Harry can spill the beans if he wishes :hammer: :headslap:

Oh, I will continue my efforts to make a disk imaging setup, I don't have a complete DOS disk, I'd like Microsoft BASIC and whatever other software I can find and I need to safeguard what software I have (Multiplan, WordStar, my NEC dos matrix printer driver)

I'll also make a better, more detailed video if anyone is interested? The quality is rubbish in this one as I only had an old Samsung galaxy tab lying around at the time.

Thanks again and goodnight!

JonB
September 10th, 2017, 01:43 AM
Hi Alan

It looks like a colour display in the video, is that right? You'll be playing Commander Keen before you know it!

I read it has high resolution graphics and could run MS-DOS and CP/M-86. Cool..

Anyway, congrats on getting it working!

Cheers
JonB

archeocomp
September 10th, 2017, 02:56 AM
VERY sweet machine!

alan8086
September 10th, 2017, 05:04 AM
Hi Alan

It looks like a colour display in the video, is that right? You'll be playing Commander Keen before you know it!

I read it has high resolution graphics and could run MS-DOS and CP/M-86. Cool..


Anyway, congrats on getting it working!

Cheers
JonB

...Yes its colour. I've only seen green text until now but the TEST disk and one of the DOS disks make use of different colours.

alan8086
September 10th, 2017, 05:10 AM
VERY sweet machine!

I suppose it is! :) I hope to realise its full potential - I've had success of sorts from my FDADAP adapter and managed to format an 8" floppy using a Pentium motherboard and an old mfm hd controller. Still wont write an .IMD file to disk yet - just says 'No interrupt from FDC' Still experimenting. The issue with the FDADAP was the cables being the wrong way round and not corresponding to the markings on the silk screen. Weirdly, if I plug in the 34 pin cable with its pin 1 in opposition to where the 50pin cables pin one is - it works! Confusing if you are convinced the silk screen numbers must be meaningful!