divide loading errors

jagman5994 · August 2012

Hi All,

Just bought a divide unit and I am having a few problems. I select the TAP file from the fatware browser, then do a load "". I get a lot of "R Tape loading error", I get a lot of black screens, I get a lot of resets. When I do eventually get a successful load, I can reset and get another successful load of the same TAP file straight away, but I cannot always get a different tap to load. To get it to load requires a lot of power offs and trying again. Holding down space while the divide starts up seems to help. Sometimes after a failed load, the fatware browser shows a whole bunch of garbage filenames.

I have tried a sandisk 256mb CF card and a kingston 1gb card. I have tried fatware 0.12a and fatware 0.12 for ZX128.
I can load from an audio source successfully 100% of the time.

I am running on a 128k heatsink model, but with slightly modified rom. After a failure a couple of weeks ago, I replaced the rom with a bugfixed one downloaded from http://www.fruitcake.plus.com/Sincla...isassembly.htm.

Does formatting the CF card with a non-default allocation unit size maike any difference? I have tried various sizes, but I still get the errors.

Has anyone got any ideas as to what I can do to fix this problem?

Thanks
Bill.

BiNMaN · August 2012

tbh I've never been successful using a modified ROM with a DivIDE, only a standard one

I wanted to use the plus2c-0.rom in a modded grey +2 (velesoft replacement HAL), but all the NMI does is reset the machine into 48K basic. I've tried to do it under emulation (spin/specemu/fuse) to save me the mither of burning a ROM but still no success. From real tape there are no problems it loads fine.

Is everything ok using the original ROM?

jagman5994 · August 2012

Not sure, as my original rom is fried! I'll download an original one and write it to an eprom and see what happens. Good to hear though that you have not had success with a non-original rom. Looks like this could be the issue.

I'll let you know what happens.

Thanks

chev · August 2012

I rather doubt the bugfixes would cause the checksum error you seem to be getting. Have you got something plugged in between the 128 and the divIDE, like a joystick interface for instance?

In terms of the best ROM to use for compatibility you want the Spectrum SE ROM set (available as part of the FUSE package). Unless you have a keypad that is. The Spectrum SE ROM set is the original 48 BASIC (so you can load stuff that checksums the ROM) and the UK 128 editor with three bytes NOPed out to enable it to work with the 48 BASIC. That will give you a much more compatible machine than using the original UK 128 ROMs.

velesoft · August 2012

As first test stability of readeing data from IDE device/Cf card.

Here is test utility:
http://www.worldofspectrum.org/forums/showthread.php?t=40024

Only load this small program to ZX and wait (30 minutes is ideal) if not sign errors....

jagman5994 · August 2012

aowen, I have nothing else plugged in at all. I have downloaded the se roms and will copy them to eprom and see if they make any difference.

But first, I am taking the advice of velesoft and running the test utility. Looks like its gonna run for quite a while.

I'll post back later and let you all know what I find.

Thanks for all your ideas. At least its given me a few things to try.

Bill.

jagman5994 · August 2012

I let the test utility run for 3 hours until it completed. It reported no errors.
I then changed my rom back to a standard 128k rom downloaded from the Philip Kendall site. I did not change to the 128 se rom from fuse because I compared the image to the standard 128k rom and there looked like a bucket load of differences. I felt safer sticking with the standard rom.

Things look better, but still not great. I am still getting loading errors and random resets.

I don't know what to try next.

Any ideas anyone?

Thanks,
Bill.

velesoft · August 2012

jagman5994 wrote: »

I let the test utility run for 3 hours until it completed. It reported no errors.
I then changed my rom back to a standard 128k rom downloaded from the Philip Kendall site. I did not change to the 128 se rom from fuse because I compared the image to the standard 128k rom and there looked like a bucket load of differences. I felt safer sticking with the standard rom.

Things look better, but still not great. I am still getting loading errors and random resets.

I don't know what to try next.

Any ideas anyone?

Thanks,
Bill.

Then test you ZX ram: (If you will test it on DIVIDE, not remove divide jumper, ignore message on screen and press enter)
http://www.worldofspectrum.org/forums/showthread.php?t=40495

jagman5994 · August 2012

I ran TESTROM3, and that also gave no errors. Nice little utility by the way :)

I have made some progress though. I opened the 128 up again and cleaned the contacts on the expansion port and things seem better.

I'll let you know what happens.

Thanks for all your help everyone.

Bill.

chev · August 2012

jagman5994 wrote: »

I then changed my rom back to a standard 128k rom downloaded from the Philip Kendall site. I did not change to the 128 se rom from fuse because I compared the image to the standard 128k rom and there looked like a bucket load of differences. I felt safer sticking with the standard rom.

diff SE-0 against the original ROM-0 and you will find three bytes changed (to NOPs). diff SE-1 against the original 48.ROM and you will find no differences (unless your download was corrupted).

By replacing the SE ROMs with the original UK ROMs you have reduced the amount of software your machine will run.

Winston · August 2012

Don't forget to check the condition of the edge connector and the connector on the DivIDE. Intermittent problems are often caused by intermittent circuits, and a bad connection between the DivIDE and edge connector may be the culprit if this is the case.

jagman5994 · August 2012

Thanks Winston, but I've already tried that. I thought cleaning the connections made a difference, but it appears not to be the case. I'm still getting random errors.

I also tried the SE rom. That did not work at all! It just caused the spectrum to restart in 48k mode whenever I pressed the button on the divide unit.

I'll continue to tinker...

chev · August 2012

jagman5994 wrote: »

I also tried the SE rom. That did not work at all! It just caused the spectrum to restart in 48k mode whenever I pressed the button on the divide unit..

It's not the ROM causing that. A 128 with a divIDE connected is supposed to boot in 48K mode. If pressing the button causes a reset then the internal NMI code (which causes a reset) is running, and that sounds like there's an issue with the ROM/CS line

jagman5994 · August 2012

aowen wrote: »

It's not the ROM causing that. A 128 with a divIDE connected is supposed to boot in 48K mode. If pressing the button causes a reset then the internal NMI code (which causes a reset) is running, and that sounds like there's an issue with the ROM/CS line

I am now running with SE. I have been trying many things and one of those was to reflash the divide with 'FATware 0.12 for ZX128 (en)'. It seems that this version of fatware does not like the SE rom. I am now back on 0.12a, but still am having problems.

I have found a pattern though. I don't know if this will mean anything to anyone, but I am hoping it will.

If I turn on the spectrum, select paperboy.tap from the browser and load, I will always get an 'R Tape Loading Error'. I will get a corrupt loading screen at exactly the same place every time.
But, If I turn on the spectrum and hold down space while I still have the divide logo up to force an init, I can then select paperboy.tap and load successfully every time!

Weird eh?

ingo · August 2012

I have made of my own two divIDE 57C. Both didn't work with all Spectrums. therefore I desoldered the transistor that inverts the /MREQ signal. Instead I soldered a TTL triggering gate (74LS14).
The modified circuit delays the /MREQ and makes /MREQ a bit shorter. Using this modified schematic the divIDE works on all Spectrums I own (gray +2, 128k heater, 48k, 48k+, harlequin).

This picture shows the schematic I used:

These photos show the (ugly) realization:

Greets Ingo.

BiNMaN · August 2012

aowen wrote: »

It's not the ROM causing that. A 128 with a divIDE connected is supposed to boot in 48K mode. If pressing the button causes a reset then the internal NMI code (which causes a reset) is running, and that sounds like there's an issue with the ROM/CS line

My DivIDE 57c boots in 128k (on both an original and a HAL replaced grey +2, toastrack etc), I'm going to get the SE rom burnt to see how it fairs with both grey machines. I'm hoping it will work with the DivIDE on the HAL replaced machine.

chev · August 2012

jagman5994 wrote: »

I am now running with SE. I have been trying many things and one of those was to reflash the divide with 'FATware 0.12 for ZX128 (en)'. It seems that this version of fatware does not like the SE rom. I am now back on 0.12a, but still am having problems.

I'd switch to esxDOS. 128 BASIC is unstable with divIDE connected which is why the device normally switches to 48 mode.

jagman5994 · August 2012

I have now tried esxDOS and have similar problems, although its not as bad. I can load a few tap files for a while, but then the browser will show only the last loaded tap over and over. i.e. I see a screen full of paperboy.tap and multiple pages of it.

before I switched to esxDOS, I tried the divide on a +3, but had similar results.

Do you think I could have a faulty divide unit?

phoenix^ra · August 2012

jagman5994 wrote: »

I have now tried esxDOS and have similar problems, although its not as bad. I can load a few tap files for a while, but then the browser will show only the last loaded tap over and over. i.e. I see a screen full of paperboy.tap and multiple pages of it.

before I switched to esxDOS, I tried the divide on a +3, but had similar results.

Do you think I could have a faulty divide unit?

When you get this behaviour, if you reinit esxDOS (reset+space), does it start working again or does it stay the same?

BiNMaN · August 2012

It's beginning to look that way (I'm no expert though), especially if you have tried it on different machines.

How many different machines have you tested it on?

jagman5994 · August 2012

phoenix^ra : Yes, when it all goes crazy, if I reset and hold space, it all returns to normal. This happens in fatware and esxdos.

BiNMaN : I have tried it on a 128K and a +3

1024MAK · August 2012

DivIDE SRAM being corrupted or losing contents maybe?

lotharek · August 2012

1024MAK wrote: »

DivIDE SRAM being corrupted or losing contents maybe?

I suspect above. Please, let me know to lotharek@lotharek.pl what is producer of sram chip ?

bverstee · November 2012

ingo wrote: »

I have made of my own two divIDE 57C. Both didn't work with all Spectrums. therefore I desoldered the transistor that inverts the /MREQ signal. Instead I soldered a TTL triggering gate (74LS14).
The modified circuit delays the /MREQ and makes /MREQ a bit shorter. Using this modified schematic the divIDE works on all Spectrums I own (gray +2, 128k heater, 48k, 48k+, harlequin).

This picture shows the schematic I used:

....

Greets Ingo.

Ingo,

I tried the mod myself, but after the mod the DivIDE bootscreen isn't shown anymore and the ZX Spectrum boots up normally.

Pics of the mod:

I think I've done exactly the same as you.
Any idea what I'm forgetting?

ingo · November 2012

Hi Ben,

actually I can not see any failure at your pictures.
I did this mod for 4 items of divIDE. All 4 are working successfully till today.

Did you use an oscilloscope to check if the circuitry is working properly? Is there the possibility of any additional problem? (short, bad IC or somethink like that)

Greets Ingo.

ingo · November 2012

You also use a 74LS14 not a HCT or HC type? I hope that I really used the type at the schematic not a difefrent technology.

bverstee · November 2012

ingo wrote: »

You also use a 74LS14 not a HCT or HC type? I hope that I really used the type at the schematic not a difefrent technology.

I tried both 74HC14 and 74LS14, but both solutions fail.
I replaced all chips on the DivIDE, but no difference.

I will:
- check for short circuits (because of soldering)
- check signals with my scope
- will try getting that DivIDE back to standard; maybe something else is failing. It worked fine before the mod however.

bverstee · November 2012

Solved the problem this morning: the 1N4148 seemed to have failed (always a first time...).

But unfortunately the mod did not get the DivIDE working on two boards.
After swapping the Z80, the DivIDE got working, so it seems that both Z80's had problems, maybe the M1 problem.

I'll continue in this topic: http://www.worldofspectrum.org/forums/showthread.php?t=40248.

ingo · August 2013

Hello,

I reactivate that thread because I found an error at my schematic I did in the past - sorry for that. Note, if you want to improve the compatibility of divIDE that I used a 74 HC14 or 74 HCT14 NOT a 74LS14. The LS needs more input current - that way my schematic would not work. I corrected the file:

Greets Ingo.

divide loading errors

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