The Sinclair QL Forum

Having written off my “spare” QL my “spare spare” QL had been promoted to “spare”

It’s currently got a Minerva ROM and I’ve tried this using standard 128k & with 512k RAM expansion

But I find it keeps going on a “go slow” like the Minerva boot screen loads with pauses and if I start typing it will display the first, say, 10 characters and then there will be a significant pause before the rest of the characters I’ve typed appear. Programs also seem to pause in-appropriately

I was wondering if anyone has any suggestions as to what might be going on please?

Many thanks

This is a total guess - but having had something similar on a z80 based system - that was down to unexpected interrupts occurring.

With the QL - this could be the extint pin getting triggered - it's a pin present on the 64 way connector - and could have got bent and be touching other pins - it should be relatively easy to see if this is the case - the pin is about 3 in from one end.

Other than that - has the board had any soldering work done - where the could be solder bridges or shorts on the PCB?

Pr0f wrote: Fri Nov 08, 2024 5:55 pm This is a total guess - but having had something similar on a z80 based system - that was down to unexpected interrupts occurring.

With the QL - this could be the extint pin getting triggered - it's a pin present on the 64 way connector - and could have got bent and be touching other pins - it should be relatively easy to see if this is the case - the pin is about 3 in from one end.

Other than that - has the board had any soldering work done - where the could be solder bridges or shorts on the PCB?

Pins are all fine

Am not aware of any soldering work, all looks original from above anyway

Many thanks

Hi,

Sounds liek the QL channel #0 input into Superbasic basic is crashing, maybe try looking at the 8049 IPC or 8032, or the decoding chips handling the data input.

The ROM maybe be faulty.

Clean all plugin chips with a Pencil Eraser.

There could be a "dry" joint, or non-conducting joint that looks OK, but is causing a faulty connection.

Derek_Stewart wrote: Sat Nov 09, 2024 7:10 am Hi,

Sounds liek the QL channel #0 input into Superbasic basic is crashing, maybe try looking at the 8049 IPC or 8032, or the decoding chips handling the data input.

The ROM maybe be faulty.

Clean all plugin chips with a Pencil Eraser.

There could be a "dry" joint, or non-conducting joint that looks OK, but is causing a faulty connection.

Thanks Derek

I decided to just “go for it” so, after cleaning the sockets, I replaced all the socketed chips with known good ones from my spares box and a quick bit of testing suggests the problem is cured.

Obviously I don’t know which was the problem one, but that’s something for another day

The only issue I can see now is that the LED for MDV2 has a slight glow when not in use (but MDV2 is working). This was happening before I swapped the IC’s though.

Many thanks

t0nyt wrote: Sat Nov 09, 2024 9:34 am
The only issue I can see now is that the LED for MDV2 has a slight glow when not in use (but MDV2 is working). This was happening before I swapped the IC’s though.

Have just realised that as soon as power is applied, but not on a reset, MDV2 spins up and straight down again (this is all BEFORE memory checks start)

(Also, If I try to initialise my vDrive on this QL I just get "vDrive not responding" so can't use vDrive/vMap commands, but I can dir MDV3_ and read from it ok)

Many thanks

EDIT: Just to be 100% clear, the vDrive works perfectly with my main QL

Does anyone have the files mentioned in the vMap user manual please?

To load the vMapQL standalone utility copy the boot and vmapql_bin files provided onto a
spare cartridge and load into mdv1.

Many thanks

I tried swapping MDV1 and MDV2 and the LED problem moved with the drive (though it didn't spin up when power applied)

So I removed the MDV unit completely and vDrive initialised OK

So I then fitted a different MDV unit, and although I don't have the LED problem now, vDrive won't initialise again

I'm confused lol

t0nyt wrote: Sat Nov 09, 2024 2:21 pm I tried swapping MDV1 and MDV2 and the LED problem moved with the drive (though it didn't spin up when power applied)

So I removed the MDV unit completely and vDrive initialised OK

So I then fitted a different MDV unit, and although I don't have the LED problem now, vDrive won't initialise again

I'm confused lol

I swapped out the Regulator & Heatsink for a modern Regulator and now vDrive initialises ok

(I tried putting the original MDV unit back, as it was a fully functional unit, but that knocked out vDrive again. Will have to test the MDV cables in case something is broken)

So at least I have the spare up and running, but MDV1 doesn't format. But I guess I can live with that for now

Many thanks

Edit: Actually MDV1 doesn’t seem to be reading either. My head hurts.

I've tracked down the "slow down" problem to the ZX8302

Have now put back all the original IC's, but with a different ZX8302, and that problem has gone

Have put back the MDV with the LED glow (which is still fully working despite the slight glow) so the QL has 2 fully working MDV's

The only thing that doesn't fully work is my vDrive (which works fine with my main QL), but I can manually pre-load images on the SD - just can't use the vMap as the vDrive/vMap software won't initialise

It will have to do until I can pick up another replacement mobo for it

Many thanks