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MAI basic four systems s/10 (4105), Help Please.

Muttley Black

Muttley Black

Experienced Member
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Aug 4, 2019
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104
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Greece
Hello all

I have a mai basic four systems s/10 (4105) but sadly in not an working order.

When i plugged it and power on the switch, what I see is some green lines for a sort of time in the screen then black screen and one of the floppy always spinning. I dont have system disks and i don't know if that normal behavior with out a system disk? I believe it's not.

I can’t find any information online, or a copy of system disks.

Any help is more than welcome.

Have a great day!

Here you can se a video of the problem: https://www.dropbox.com/s/3dbhla003g8md7w/IMG_7210.MOV?dl=0

Here some photos :

image3.jpeg
image0.jpeg
 
What CPU does it have? If it is a Z80, 8080 or 8085 then there is a small chance that it is a CP/M machine and you can ask in the CP/M section.
 
I didnt know they made a basic 4 so small? Are we sure that isnt just the terminal with floppy drives built in? I was under the impression they were all mini computers like my Basic 4.
 
Yup, they even produced an 80286 box. But here's some info on the OP's system:

M.A.I. S10 Basic Four

www.obsoletecomputermuseum.org

From the description, you'll need the IPL floppy to do anything.

However, http://www.ardiehl.de/basicfour/ says that both the Business BASIC and the CP/M boot disks are availabe on Dave Dunfield's Site.

(It took me about 2 minutes to find all this online. You need to improve your browsing skills :) )
 
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Hello again!

Yes i found all that online and btw Dave Dunfield's Site. is down. what i meant, is that i didn't find infos for my symptoms. I don't know if you see my video. And yes this is Z80 CPU machine
 
If you read the description in my first link, yours has normal operation--nothing really happens until the IPL floppy loads. Which is why I said that you won't get anywhere without one.
In any case, Dave's system/install disk archive is here. It does include disk images for the MAI BASIC/4 system here.

You're welcome.
 
Yes, please let us know. I have one as well (slightly different keyboard) but I haven't powered it up in a while and mine has a big thick ribbon cable coming out of the back like it needs to connect to something.
 
snuci said:
Yes, please let us know. I have one as well (slightly different keyboard) but I haven't powered it up in a while and mine has a big thick ribbon cable coming out of the back like it needs to connect to something.
Click to expand...
I believe that there was an external hard drive option for the system. I suspect that's what the cable is for.
s10_01.gif
 
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I have one as well. When I first got it, it powered up OK and booted (CP/M, I think). At some point it died while booting. That was many years ago. I suspect power supply problems, but I never had the time to track it down. I ought to get it out and make an attempt at fixing it. It seemed to be a pretty nice system. I also have an MAI mini (68010 based) that was used in a small office environment (maybe 4 remote terminals?). Sadly, the hard drive in that one doesn't spin up anymore.

From the looks of it (in your video), I'd suspect there is a problem with the CRT.

Roger
 
Chuck(G) said:
I believe that there was an external hard drive option for the system. I suspect that's what the cable is for.
s10_01.gif
Click to expand...
I pulled mine out as well now and will need to check some caps tomorrow before powering it up. This is a quick pic of the extra card with the ribbon cable attached. It is a 50 pin ribbon cable so I a immediately thought SCSI but I'm not sure if this is a standard interface or not. for a WDD "Winchester Disk Drive"?

card_front (Medium).JPG

If you had a picture in your post, it wasn't visible.

Thanks Chuck(G).
 
In my post, the small box next to the CPU box is the hard disk drive, also shown in the small photo at http://www.ardiehl.de/basicfour/. At any rate, that's very likely the interface to a WD1000 or similar hard disk controller. The legend "WDD Interface Board" (Winchester Disk Drive) on the PCB and the presence of the 220/330 termination pack pretty much cinches it. The interface isn't complicated, just a Z80 PIO driven by a Z80 CPU. Apparently the board plugs into a 40 pin DIP socket on the main board, judging from the male connector (careful that you don't bend those pins!)

I suspect, just like some of the TRS-80 early hard drives, that the box contains a controller (probably WD) and an 8" drive, probably a Shugart SA-1000, and power supply.

The solder side of that card might actually help determine specifically what the controller in the hard drive box was.
 
norwestrzh said:
From the looks of it (in your video), I'd suspect there is a problem with the CRT.
Click to expand...
As soon as i figure it out how i use ImageDisk 119 on dos system to write cp/m.imd on a floppy disk and do my first try to boot the system, i will tell you. If i don't have good news i will do a full recap on crt board, check all the voltages etc. Something that i will do no matter what. Till now what i have already done is to check both z80 & z80ctc, all 4116 dram ic's with my BK Precision 575 tester and they are all in working order. Unplug and clean every socket and IC's and put them back again.
 
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Can anyone help what parameters/ setting’s should I put to the program to be able to write cp/m.imd image to disk. I use dos 6.22

750857D9-F1E9-4B0E-AA48-46956FB0B635.jpeg
 
Unfortunately, mine has no high voltage but I do have fan spin so I may have an issue with my power supply. Visually, everything looks okay but maybe not. I would have tried writing these disks and seeing if they worked before commenting on your post @Muttley Black . I don't have my disk making computer out yet but check the README fie that states:

"To view the details of a disk image, please use the IMDAM utility provided with ImageDisk. You can also simply TYPE the file to view the image comment". I was going to try that direct but otherwise, I would have tried with a simple "double step" setting on and tried to write out the disk to try it. Other than the drive letter, I don't think you need to specify anything else.
 
My dos system is a Pentium MMX 166 with 5.25 1.2mb floppy. As OS, I have installed only the 6.22 ms-dos.
 
snuci said:
I would have tried with a simple "double step" setting on and tried to write out the disk to try it. Other than the drive letter, I don't think you need to specify anything else.
Click to expand...
I did that and what i get is write error - no data. Seems try to white but with error.

But it’s not only that. To continue to write of format ask not only the drive letter. Ask also for sides and interleave, sectors/track in format, start sector, mfm kbps, sector size.

Ok some infos I have them by read the content of image (.imd file) with imdv. But what about interleave?

I do serval try’s to white an image to disk but with no luck. :)
 
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