DivMMX x2 cannot get it to work

Post Reply
repetto74
Posts: 69
Joined: Tue Dec 20, 2016 8:46 pm

DivMMX x2 cannot get it to work

Post by repetto74 »

:?

Guys I am desperate to get the DIVMMCx2 to work. I bought this from 8BITS4EVER and followed the installation guide.
I have set the jumper to 1 for the ZX Spectrum 48K. I have then a 256MB SD card in FAT32 format where I copy all the needed folders in the root directory

/BIN
/SYS
/TAPE48K
/TAPE128K
/Util
etc..

When turning on the Spectrum ZX I can briefly see the ESXDOS booting screen the back to the ZX Spectrum prompt screen. Pushing the NMI button on the DIVMMC will just load a garbled screen as in attachments.

If someone knows where I am wrong before claiming for a replacement?
My ZX spectrum is fully working, tested also with an old cassette deck and a bunch of old games on tape and they will load successfully. Never tested the expansion port though this is the first time a peripheral is connected to it. :roll:

Do not pay attention to the wrong colors on screen, this is an issue with the composite input of my LCD screen.
Attachments
IMG_5512.JPG
(1.18 MiB) Downloaded 519 times
IMG_5508.JPG
(1.39 MiB) Downloaded 519 times
IMG_5505.JPG
(1.59 MiB) Downloaded 519 times
User avatar
Fwapp
Posts: 152
Joined: Mon Jun 01, 2015 10:32 pm

Re: DivMMX x2 cannot get it to work

Post by Fwapp »

First, try setting the device to a different type of Spectrum.

I have toastrack that needs to be set as not a toastrack to work.

The other thing that these devices need is a Z80 with a decent M1 line, can you try it on another Spectrum, as it might just be the Z80 cpu at fault.
ZX80, ZX81 - 2C158C Bugged Rom iss.1, 2C158C "kludge fix" iss1, 2C184E iss1, 2C210E iss3, US NTSC iss1 "straight traces", US NTSC iss3 TS1000
User avatar
1024MAK
Posts: 5103
Joined: Mon Sep 26, 2011 10:56 am
Location: Looking forward to summer in Somerset, UK...

Re: DivMMX x2 cannot get it to work

Post by 1024MAK »

Also clean the edge connector contacts with IPA / electronic solvent cleaner. Don't use any switch cleaner that has an oil or lubricant content.

Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp

:!: Standby alert :!:
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb :!:
Looking forward to summer later in the year.
RWAP
Posts: 1348
Joined: Thu May 08, 2008 8:42 am
Location: Stoke-on-Trent, UK
Contact:

Re: DivMMX x2 cannot get it to work

Post by RWAP »

If the above don't help - try reformatting the SD card and trying again. Are you sure it is not a fake SD card too - I know the fake Compact Flash cards give a lot of problems with various interfaces - not sure about SD cards...
repetto74
Posts: 69
Joined: Tue Dec 20, 2016 8:46 pm

Re: DivMMX x2 cannot get it to work

Post by repetto74 »

Hi,

Hope it Is not the CPU but honestly this Spectrum is fully working. I can load games and do programming with no issue so I really doubt CPU is at fault. Unfortunately I cannot test it on another Spectrum.
Have both tried jumpers on 1 ON and 1&3 ON but same result.
I may now as suggested clean port contacts with alcohol first and try with another SD card.
Could you please confirm that file structure on the SD is correct?
Strangely I have a doubt on the exsdos boot screen as I think that necessary files are not loaded properly before getting back to the main prompt screen. I do only see "loading exsdos" where normally I should see also other files being loaded into memory.
RWAP
Posts: 1348
Joined: Thu May 08, 2008 8:42 am
Location: Stoke-on-Trent, UK
Contact:

Re: DivMMX x2 cannot get it to work

Post by RWAP »

The file structure looks ok - but I guess you do not see the OK after loading esxdos.sys and loading nmi.sys ??

Some Z80s lack the M1 line which is essential for this type of device unfortunately - so it could be that, but if it crashes on loading esxdos.sys suggests the files on your SD card might be corrupt.
repetto74
Posts: 69
Joined: Tue Dec 20, 2016 8:46 pm

Re: DivMMX x2 cannot get it to work

Post by repetto74 »

Hi RWAP

So I have things moving a little bit :ugeek:
I have cleaned contacts on both sides with alcohol and looks good and have format another SD card (4GB) in FAT32 and installed the set of folder in the root directory.
Now switching on the ZX will move the booting up but still getting an error for one specific file (RTC.sys) but this file is not present in the SYS folder. Pushing the NMI red button will give then a black screen with bars on top and bottom.

Now I do not know what has caused the booting to proceed either having changed the card or the cleaning. Maybe more cleaning is needed? Is this RTC.sys required as it is not included in the package to be copied in the bootable SD card :? :?
:?: :?:
red and yellow light are lit on the DIVMMC not the third one I assume green.

EDIT : Ok actually I have seen a demo running the DIVMMC on a ZX Spectrum and I have noticed that at boot up also the RTC.sys is at Error but then the menu will pop up when pushing the NMI button. In my case I can only see the top and bottom borders but not the content of the SD card :cry:


EDIT 2 !!! : Ok I have replaced BIN and SYS from the one of EXSDOS version 0.8.6 and now I can access the SD folders from Menu! :D :D :D :D Fewwwwwwwwwww!!
Attachments
IMG_5515.JPG
(1.19 MiB) Downloaded 479 times
IMG_5516.JPG
(1.02 MiB) Downloaded 479 times
RWAP
Posts: 1348
Joined: Thu May 08, 2008 8:42 am
Location: Stoke-on-Trent, UK
Contact:

Re: DivMMX x2 cannot get it to work

Post by RWAP »

Glad you fixed it - it might be worth letting the seller know that the files were corrupt (or possibly out of date)....
repetto74
Posts: 69
Joined: Tue Dec 20, 2016 8:46 pm

Re: DivMMX x2 cannot get it to work

Post by repetto74 »

Hi RWAP
The seller did provide also a copy of bin and sys files for version 0.8.6 together with the 0.8.5 but the last is not working at least for me.
I assume anyway that manual is not very clear on how to troubleshoot those kinds of problems
Anyway luckily all is working now :-)
Post Reply